nesa- inquiry, the nature of science, and technology abilities to do scientific inquiry sc 12.1.1...

NeSA- INQUIRY, THE NATURE OF SCIENCE, AND TECHNOLOGY

Abilities to do Scientific Inquiry

SC 12.1.1 Students will design and conduct investigations that lead to the use of logic and

evidence in the formulation of scientific explanations and models.

Standard-SC 12.1.1.a 2

OBJECTIVE

PRACTICE

•Formulate a testable hypothesis supported by prior knowledge to guide an investigation

A scientific hypothesis is a prediction which can be tested through controlled experimentation. Scientists base their hypotheses on observations, questions, previous knowledge (knowledge of scientific literature) and interpretations (biases).

1. Which of the following is/are commonly used to establish a hypothesis?

a. scientific literature b. observations

c. previous personal knowledge d. all of these

2. A hypothesis must be both a prediction and be testable. a. true b. false


ANSWERS & EXPLANATION

1. (d) all of the above Scientists design hypotheses based on observations of events, previous knowledge they

have, knowledge that is contained in scientific literature and interpretations they have regarding possible relationships they can predict. Hypothesis propose a logical outcomes of events that occur through manipulating variables.

2. (a) true

In order for a hypothesis to be tested in a scientific experiment it must make a prediction based on changes in independent variables and must be a statement that can be tested through controlled experimentation.

Key Terms

hypothesis a testable statement about the natural world that can be used to develop inferences and explanations

Standard-SC 12.1.1.b 4

OBJECTIVE

PRACTICE

•Design and conduct logical and sequential scientific investigations with repeated trials and apply findings to new investigations

The scientific method is the process by which scientists conduct controlled experiments. This form of scientific inquiry tests single variables (independent variable) by measuring its affect on another variable (dependent variable)

1. The variable that is altered by the scientist in a controlled experiment is identified as

a. independent b. dependent c. controlled

2. A controlled variable is a. changed in each trial b. allowed to change in

trials c. held constant in each trial



1. (a) independent

A scientists purposefully alters ONE variable in an experiment in order to test changes in another variable.

2. (c) held constant in each trial

Controlled variables are conditions in an experiment that should not affect the dependent variable. These should be the same for all individual trials.

Key Terms

control group a group of subjects, closely resembling the experimental group but not receiving the factor under study, which serves as a comparison to the experimental group

experimental group

a group of subjects which receive the factor under study

Standard-SC 12.1.1.c 6

OBJECTIVE

PRACTICE

•SC 12.1.1.c Identify and manage variables and constraints

Scientific investigations are designed to test one variables (independent variable) influence on another variable (dependent variable) while attempting to keep all other variables constant (controlled variables).

1. A study comparing the weight gain in mice due to the amount of fat in their diet was conducted. What is the independent variable?

a. amount of fat b. weight gain c. mass of food

2. In the same study above, what is the dependent variable? a. amount of fat b. weight gain c. mass of

food



1. (a) amount of fat

The research was studying the amount of fat in the diet and how it affects the weight gain in mice. The amount of fat in the diet was determined by the scientist and the weight gain by the mice was an effect of fat changes. The amount of fat is the independent variable because it is the variable that was purposefully changed.

2. (b) weight gain

The weight gain by the mice was analyzed by comparing it to the amount of fat in the diets of the mice. The weight gain is considered dependent on amount of fat.

Standard-SC 12.1.1.d 8

OBJECTIVE

PRACTICE

•Select and use lab equipment and technology appropriately and accurately

In order to conduct sound scientific investigations scientists must use appropriate equipment, data collecting instruments/devices and analyze data using appropriate means. Much of the collecting and analysis of data is done with technology.

1. In order to test the acidity of a solution, a scientist would need a a. balanceb. scale c. pH meter d. meter stick

2. What measure would a beaker or flask be able to provide? a. mass b. length c. density d. volume



1. (c) a pH meter

pH meters measure the acidity of a solution based on the concentration of hydrogen ions (H+) that exist in solution. The greater the concentration of hydrogen ions, the higher the acidity and the lower on the pH scale it is. Acids have pH values which are less than 7 and bases have pH values greater than 7

2. (d) volume

Beakers and flasks measure the volume of liquids (or gases) in the container.

Standard-SC 12.1.1.e 10

OBJECTIVE

PRACTICE

•Use tools and technology to make detailed qualitative and quantitative observations

During a scientific investigation scientists must be able to make observations and measures which are free of bias. Two types of observations are quantitative (numeric) and qualitative (a description).

1. An observation that describes the color of an objective would be

a. qualitative b. quantitative c. neither

2. A quantitative observation can be a. a count b. a measure c. both a & b



1. (a) qualitative

Qualitative observations describe the physical attributes of an object. Examples are color, shape, texture, odor and taste.

2. (c) both a & b

Quantitative observations are numeric descriptions of an object. Two ways that numeric observations can be made are counting objects or measuring objects. Measures can include mass, volume, length, density, brightness, and area.

Standard-SC 12.1.1.f 12

OBJECTIVE

PRACTICE

•Represent and review collected data in a systematic, accurate, and objective manner

Scientists normally collect data from experiments and organize it into tables where changes in the dependent variables are recorded in relation to changes in the independent variable.

Student finger length (cm) finger circumference (cm)

Luke 8.1 8.0

Angelina 5.1 4.2

Marcie 4.2 4.5

Pham 7.2 6.3

Wendy 5.6 4.9

1. Which student has the second longest finger? a. Luke b. Wendy c. Pham d. Marcie

2. Which student has the smallest length to circumference ratio? a. Luke b. Angelina c. Wendy d. Marcie



Student finger length (cm) finger circumference (cm)

Luke 8.1 8.0

Angelina 5.1 4.2

Marcie 4.2 4.5

Pham 7.2 6.3

Wendy 5.6 4.9

1. (c) Pham

Luke has the longest finger (8.1 cm) and Pham has the second longest (7.2 cm)

2. (d) Marcie

Marcie has the lowest ratio of length to circumference. She is the only student who has a finger which is shorter than the circumference. This puts her ratio lower than 1. All other students have ratios greater than 1 because their lengths are greater than their circumferences.

Standard-SC 12.1.1.g 14

OBJECTIVE

PRACTICE

•Analyze and interpret data, synthesize ideas, formulate and evaluate models, and clarify concepts and explanations

Upon completing a scientific experiment and collecting non-biased data, a scientist must analyze the data and represent the results in a way that shows the relationship between the dependent and independent variable. Graphs are usually used to represent these relationships.

1. Which region of the brain has the most receptor binding sites? a. 1 b. 2 c. 3 d. 4

2. If region 1 is the outer most region and 4 is the inner most region, where are most receptor binding sites found? a. outer b. inner c. they are the same



1. (b) 2

Brain region #2 has over 50 binding sites where the other three regions have less than 40 binding sites.

2. (a) outer

The outer regions ( regions 1 & 2) have more receptors than the inner regions (regions 3 & 4)

Key Terms

theory a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses

Standard-SC 12.1.1.h 16

OBJECTIVE

PRACTICE

•Use results to verify or refute a hypothesis

A conclusion is a statement that uses the results from an experiment to explain whether a hypothesis can be accepted, refuted or needs modification.

1. A conclusion has to be a statement which answers the validity of a

a. hypothesis b. result c. data d. observation

2. The conclusion should describe the relationship between the dependent variable and the

a. controlled variable b. dependent variable c. independent variable



1. (a) hypothesis

The conclusion needs to explain whether the data & results supported or did not support the hypothesis.

2. (c) independent

Remember the hypothesis is a prediction of how a dependent variable will change in relation to an independent variable. The conclusion should state if the prediction was valid or not valid, based on what the results showed.

Standard-SC 12.1.1.i 18

OBJECTIVE

PRACTICE

•Propose and/or evaluate possible revisions and alternate explanations

A scientific discussion is the explanation following a conclusion which describes the research, identifies possible errors within the research, proposes possible changes in the procedure and compares the conclusion to existing knowledge.

1. A student predicted their dog would lose mass through the winter and spring. Did the results support their hypothesis? How should they change their hypothesis?



1. The student’s hypothesis did not match their results. They predicted the dog would lose mass when it really gained mass. The results shows that the masses for each month increases from January to February.

The student should reject the hypothesis and restate it saying that their dog increases mass through the winter and spring.

Standard-SC 12.1.1.j 20

OBJECTIVE

PRACTICE

•Share information, procedures, results, conclusions, and defend findings to a scientific community (peers, science fair audience, policy makers)

Scientists share the outcomes of research by publishing their findings in journals which are designed to evaluate the work through peer editing. It is this sharing that allows science to continually correct our understanding of the world around us.

1. Tabloids, twitter and facebook are great sources of scientific research.

a. true b. false

2. Why does scientific research need to be reviewed by the scientific community?



1. (b) false

Scientists commonly seek to publish their work in highly respected and peer-reviewed sources, such as scientific journal like Science, Nature, Annual Review of Biochemistry & Cell. These are highly ranked science journals.

2. The process of reviewing scientific research allows other scientists to evaluate each others work. This is important so that incorrect work is not published and that science continues to find better explanations.

Standard-SC 12.1.1.k 22

OBJECTIVE

PRACTICE

•Evaluate scientific investigations and offer revisions and new ideas as appropriate

The body of knowledge known as Science is a continually growing set of facts, ideas and predictions which are evaluated by other scientists, policy makers and other community individuals. This knowledge is built on everyone’s ability to question results, conduct further research and compare different ideas.

1. Explain why it is important that scientists attend conferences, discuss their work and collaborate with each other on research projects.



1. Scientific conferences are places where scientists who share a common interest or research subject meet to discuss current research and newly found information. They provide an opportunity for scientists to clarify their own research and develop new research directions.

The October 1927 Fifth Solvay International Conference on Electrons and Photons, where the world's most notable physicists met to discuss the newly formulated quantum theory. The leading figures were Albert Einstein and Niels Bohr. Seventeen of the twenty-nine attendees were or became Nobel Prize winners, including Marie Curie, who alone among them, had won Nobel Prizes in two separate scientific disciplines.

Standard-SC 12.1.1.l 24

OBJECTIVE

PRACTICE

•Use appropriate mathematics in all aspects of scientific inquiry

Mathematics is the process by which data is analyzed. Scientists use mathematic principles to seek relationships between variables in an experiment. Most graphs represent a mathematic model, outlining these relationships.

1. Which of the lines in the graph above has a greater slope? a. red line b. black line

Standard-SC 12.1.1.l 25


1. (a) red line

Data represented on a graph can be expressed as a mathematic equation. The slope of a line shows the linear relationship between two variables. A more vertical line has a greater slope and a more horizontal line has a less slope.

NeSA- Physical Science

Matter

SC 12.2.1 Students will investigate and describe matter in terms of its structure, composition and conservation.

Standard- SC 12.2.1.a 27

OBJECTIVE

PRACTICE

•Recognize bonding occurs when outer electrons are transferred (ionic) or shared (covalent)

-Ionic bonds are formed between metals and nonmetals when electrons are transferred. This forms an ionic compound, also called a salt.-Covalent bonds are formed between two nonmetals when they share electrons. This forms a covalent compound called a molecule

1. Which element below would form an ionic bond with iron?a. sodium b. oxygen c. gold d. copper

2. Chlorine atoms have 7 valence electrons. How many covalent bonds do they commonly form?

a. one b. two c. three d. eight



1. (b) Iron reacts with oxygen

Ionic bonds occur between metals and nonmetals. Metals lose electrons to nonmetals because nonmetals have high pulls on electrons and metals have low pulls on electrons. Losing electrons is called oxidation and gaining electrons is called reduction. Iron reacts with oxygen to form rust, ferric oxide, Fe2O3

2. (a) Chlorine normally forms 1 covalent bond with other nonmetals.

Nonmetals share their electrons with other nonmetals in order to fill their valence shell with eight electrons. They share because two nonmetals both have high pulls on electrons and therefore overlap to share electrons.

Key Termschemical bonding an attraction between two or more atoms resulting in the formation of different chemical substances

covalent bond a form of chemical bond characterized by the sharing of a pair of valence electrons between atoms

ionic bond a form of chemical bond characterized by transfer of electrons from one atom to another resulting in the attraction of oppositely charged ions

molecule a group of atoms bonded together forming the smallest fundamental unit of a pure substance

valence electrons the electrons in the outer shell or energy level that are available for bonding


OBJECTIVE

PRACTICE

•Describe the energy transfer associated with phase changes between solids, liquids, and gasses

Solid particles have the lowest energy and highest attraction. Melting occurs when heat overcomes the attractions and separates solid particles. Boiling occurs when liquid particles gain more heat to escape from each other’s attractions.

1. Which of the following processes are endothermic? a. melting b. freezing c. boiling d. both a & c

2. When ice melts in your hand, energy moves from a. your hand to the ice b. the ice to your hand e. no movement of energy



1. (d) Both melting and boiling

Both melting and boiling require an input of heat, endothermic. Freezing occurs when liquid particles lose energy and form a solid.

2. (a) your hand to the ice

Thermal energy moves from areas of high concentration (hotter) to areas of low concentration (colder) until a thermal equilibrium is obtained (temperatures become the same). For the ice to melt it has to gain heat which your hand provides. Your hand feels cold because it has lost heat.


OBJECTIVE

PRACTICE

• Describe the three normal states of matter (solid, liquid, gas) in terms of energy, particle arrangement, particle motion, and strength of bond between molecules

1. Which state of matter has particles with the highest energy? a. solid b. liquid c. gas

2. Which state of matter has constant shape and volume? a. solid b. liquid c. gas



1. (c) gas

Energy is either input into a substance or released from a substance. If energy is put in, the particles move faster and overcome their attractions. The movement of particles is a measure of energy. The more energy they gain, the faster they move. Solids become liquids and liquids become gases as the particles gain energy.When particles lose energy, they slow down and the attractions become greater. Gases become liquids and liquids become solids as their energy is released.

2. (a) solid

Solid particles have the lowest energy and the highest attraction. The particles in a solid are therefore held into place (constant shape) through strong attractions and not free to move (constant volume).


OBJECTIVE

PRACTICE

• Recognize a large number of chemical reactions involve the transfer of either electrons (oxidation/reduction) or hydrogen ions (acid/base) between reacting ions, molecules, or atoms

Redox reactions occur when one particle loses an electron and another gains an electron.

Acid/base reactions occur when an acid donates a hydrogen ion (accepting electrons) and a base accepts a hydrogen ion (donating electrons).

1. Iron oxidizes in the presence of oxygen to form rust (iron oxide). What charge does the iron become if it is oxidized?

a. negative b. positive c. neutral

2. Which of the following is true about bases? a. they donate hydrogen ions b. they accept electrons c. they accept hydrogen ions d. none of the above


ANSWERS & EXPLANATION1. (b) positive

Oxidation occurs when an atom loses electrons. Losing electrons causes an atom to have more protons than electrons, which makes the atom more positive.

Reduction occurs when an atom gains electrons. Gaining electrons causes an atom to have more electrons than protons, which makes the atom more negative. Think of reduction as reducing charge by gaining electrons.

2. (c) accept hydrogen ions

Acids are hydrogen ion donors and bases are hydrogen ion acceptors. You may also hear acids as proton donors and bases are proton acceptors because a hydrogen ion and a proton are basically the same thing. In order to lose a hydrogen ion to a base, the base must have a pair of electrons which the hydrogen can bond to (formation of a new covalent bond).

acid a substance that dissolves in water to release a hydrogen ion (H+)

base a substance that dissolves in water to release a hydroxide ion (OH-)

chemical reactions

changes in chemical substances involving bond breaking and/or bond forming resulting in different chemical substances

Key Terms


OBJECTIVE

PRACTICE

• Identify factors affecting rates of chemical reactions (temperature, particle size, surface area)

1. Temperature- particles move faster and interact more2. Surface area- the smaller the “pieces” are, the more they will interact.3. Concentration- more particles in a space means more interactions4. Catalysts increase interactions without changing themselves

A chemical reaction requires reactant particles to interact. Any factor that increases the interactions will increase the reaction rate. Here are four common factors :

1. The rate of a reaction is measured by how fast reactants become products. a. true b. false

2. Which of the following will NOT increase the rate of a chemical reaction? a. increasing temperature b. having gas particles instead of solid particles c. decreasing concentration d. adding a catalyst



1. (a) true

The rate of a chemical reaction is measured by how fast reactants are converted to products.

2. (c) decreasing concentration

The rate of a reaction is affected by how fast reactants particles interact with each other. If the concentration of reactants is decreased (more spread out) the less they interact and the reaction rate decreases.

Key Terms

pH the measure of acidity or alkalinity of a solution

rate of chemical reaction

the speed at which chemical reactions occur affected by factors such as temperature, substance surface area, agitation, and pH


OBJECTIVE

PRACTICE

• Recognize the charges and relative locations of subatomic particles (neutrons, protons, electrons)

1. Which of the following subatomic particles is found in the nucleus and has a positive charge?

a. neutron b. proton c. electron d. quark

2. Which of the subatomic particles has the smallest mass? a. neutron b. proton c. electron



1. (b) proton

The proton has a positive charge and is located in the nucleus. Neutrons have no charge and are located in the nucleus. Electrons have a negative charge and are located in the energy levels outside the nucleus

2. (c) electron

The electron has the smallest mass of the particles, approximately 1/2000th the size of a proton or neutron. The neutron and proton both have approximately the same mass.

electron a negatively charged subatomic particle located outside the nucleus

neutron a neutral subatomic particle located inside the nucleusproton a positively charged subatomic particle located inside the nucleus

Key Terms


OBJECTIVE

PRACTICE

• Describe properties of atoms, ions, and isotopes

Isotopes are atoms of an element that have the same number of protons but different numbers of neutrons.

Atoms are the smallest particles of matter which have the properties of that matter. They are electrically neutral (equal protons and electrons). Ions are atoms which have gained electrons (anions) or lost electrons (cations).

1. An oxygen atom has an atomic number of 8 (contains 8 protons). How many electrons does an oxygen atom contain?

a. 4 b. 6 c. 8 d. 10

2. The atomic number for lithium is 3 (3 protons). How many neutrons does the Lithium-7 isotope (7Li) contain? a. 3 b. 4 c. 5 d. 0



1. (c) 8

The atomic number of an element is the number of protons found in the nucleus. Every atom, ions or isotope of a specific element contains the same number of protons. Atoms are electrically neutral and therefore contain the same number of protons and electrons. Oxygen atoms all contain 8 protons and 8 electrons.

2. (b) 4

Isotopes are atoms of an element that have different numbers of neutrons. The mass number of an isotope is equal to the number of protons + neutrons and is used to identify the specific isotope. This number is written after the name or as the upper left superscript with the symbol. Lithium-7 (7Li) would be an isotope of lithium which has 3 protons and 4 neutrons (3 + 4 = 7).

Key Terms

ion an atom or group of atoms in which the number of electrons is different from the number of protons resulting in a net charge other than zero

isotopes atoms of the same element with different numbers of neutrons


OBJECTIVE

PRACTICE

• Describe the organization of the periodic table of elements with respect to patterns of physical and chemical properties

The periodic table to the right shows two sets of trends, the red arrows show increasing trends to upper right and the blue arrows shows the increasing trends to lower left.

1. Which of the following elements has the largest atomic radius? a. neon (noble gas) b. chlorine (halogen) c. potassium (alkali metal)

2. Which family of elements have the highest pull on their electrons? a. alkali metals b. transition metals c. noble gases



1. (c) potassium (alkali metal)

The trend for atomic radius is to increase towards the bottom left of the periodic tables. Metals have larger radii than metals in the same period due to having lower pulls on their electrons. Nonmetals have a higher pull on their electrons and therefore are smaller than metals in the same period.

2. (c) noble gases

The trend for pull on electrons is to increase to the upper right. Nonmetals have high pulls on their electrons, are smaller atoms than metals and tend to gain electrons. Metals have lower pulls on their electrons, are larger than metals and tend to lose electrons.

Key Terms

periodic law the law stating many physical and chemical properties of the elements recur periodically as their atomic numbers increase


Force and Motion

SC 12.2.2 Students will investigate and describe the nature of field forces and their interactions with

matter.


OBJECTIVE

PRACTICE

• Describe motion with respect to displacement and acceleration

Displacement is the distance travelled from the starting point with direction. Velocity is the rate at which an object changes its displacement.Acceleration is the rate at which an object changes its velocity.

1. What is the displacement of a car moving with a uniform velocity of20 meters per second west for 40 seconds?a. 200 meters b. 200 meters westc. 800 meters d. 800 meters west

2.What is the acceleration of the object represented by the following graph if it is travelling north?a.2 m/s2 north b. 4 m/s2 northc. 8 m/s2 north d. 12 m/s2 north

Standard-SC 12.2.2.a

45


1. (d) 800 meters west

Displacement is a vector quantity that must include direction.

20 m/s * 40 s = 800 meters west

2. (b) 4 m/s2 north

The slope of a velocity/time graph is the acceleration of the object.

Key Terms

acceleration change in velocity (a = Δv /Δt)

displacement change in position from one point to another (distance and direction)

v = d/t velocity = displacement / time


OBJECTIVE

PRACTICE

• Describe how the law of inertia (Newton's 1st law) is evident in a real-world event

Newton’s 1st law is the law of inertia. It states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

1. What force causes a projectile to follow a curved path?a. gravity b. frictionc. air resistance d. none of the above

2. Why does a chair stay at rest on the floor?a. No forces are acting upon it. b. The forces acting on the chair are unbalanced.c. The net force on the chair is zero d. None of the above



1. (a) gravity

Projectiles accelerate toward the center of the earth due to the force of gravity. Therefore they follow a curved path.

2. (c) The net force on the chair is zero.

If an unbalanced force acts on the chair its velocity will change.

inertia the tendency of an object to resist any change in its motion

Key Terms


OBJECTIVE

PRACTICE

• Make predictions based on relationships among net force, mass, and acceleration (Newton's 2nd law)

Newton’s second law states that the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object. This is often represented by the equation Force = Mass * Acceleration.

1. For any object, the greater the force that's applied to it, the greater its ____ will be.a. inertia b. acceleration c. gravity d. velocity

2. A 3,000-N force acts on a 200-kg object. The acceleration of the object is ____.a. 50 m/s2 b. 150 m/s2

c. 15 m/s2 d. 26 m/s2



1. (b) acceleration

A net force on an object will cause it to accelerate.

2. (b) 150 m/s2

By using the equation F=ma we can find that 3000 N / 200 kg = 150 m/s2.

F = ma force = (mass)(acceleration)net force vector sum of all forces acting upon an object

Newton's 2nd Law the relationship among net force, mass, and acceleration (F = ma)

Key Terms


OBJECTIVE

PRACTICE

• Recognize that all forces occur in equal and opposite pairs (Newton's 3rd law)

1. When a force is exerted on a box, an equal and opposite force is exerted by the box. These forces are called ____ forces.a. frictional b. gravitational c. action-reaction d. centripetal

2.If the earth exerts a gravitational force of 980 N on you, what force do you exert on the earth?a. 980 N in the same direction b. 980 N in the opposite directionc. 0 N d. not enough information provided

Newton's third law states that for every action, there is an equal and opposite reaction. Therefore, all forces occur in pairs that are equal in magnitude and opposite in direction.



1. (c) action/reaction

When you exert a force on a box, the box provides a reaction force in the opposite direction on you.

2. (b) 980 N in the opposite direction

All action/reaction forces come in pairs that are equal in magnitude and opposite in direction.

Newton's 3rd Law all forces occur in equal and opposite pairs

Key Terms


OBJECTIVE

PRACTICE

• Describe how Newton's 3rd law of motion is evident in a real-world event

1. In the above picture the magnitude of the force the bat exerts on the ball is _______ the magnitude of the force that the ball exerts on the bat.

a. greater than b. less thanc. equal to

2. What force propels a rocket and allows it to accelerate through space?a. the action force of the rocket on the gasb. the reaction force of the gas on the rocketc. neither

All forces that occur have a reactionary force. These reactionary forces are equal in magnitude and opposite in direction to the action force.



1. (c) equal to

All action/reaction forces come in pairs that are equal in magnitude and opposite in direction. Therefore the force on both is the same.

2. (b) the reaction force of the gas on the rocket

The reaction force of the gas on the rocket causes the rocket to accelerate. The action force of the rocket on the gas causes the gas to accelerate.


OBJECTIVE

PRACTICE

•Describe gravity as a force that each mass exerts on another mass, which is proportional to the masses and the distance between them.

1. The size of the gravitational force between two objects depends on their ____.a. inertia b. frictional forces c. speed and direction d. masses and the distance between them

2. The force of gravity between two objects is 10.0 Newtons. If the distance between them is doubled, what is the new gravitational force?a. 2.5 Newtons b. 5.0 Newtonsc. 10.0 Newtons d. 20.0 Newtons

Gravity is an attractive force between any two objects which have mass. It is directly related to the masses of the two objects and inversely proportional to the square of the distance between them. The equation which describes this relationship is



1. (d) masses and distance between them

From the equation:

We can see that the force of gravity is dependent upon both the masses of the two objects and the distance between them.

2. (a) 2.5 Newtons

Increasing the distance between two objects decreases the force of gravity between them. The force of gravity is inversely proportional to the square of the distance between two objects. If the distance between two objects is doubled the force of gravity will be decreases by a factor of 4 (22 = 4).

10 Newtons / 4 = 2.5 Newtons

Newton's Law of Universal Gravitation

every mass attracts every other mass with a force directly proportional to the masses and inversely proportional to the distance between them

Key Terms


OBJECTIVE

PRACTICE

•Recognize that an attractive or repulsive electric force exists between two charged particles and that this force is proportional to the magnitude of the charges and the distance between them

Coulomb’s law states that the force between two charged particles is directly related to the charge of the particles and inversely related to the square of the distance between them. The equation that describes this relationship is

1. The force between two positively charged particles is a. attractive b. repulsive c. both attractive and repulsive

2. One positively charged particle and one negatively charged particle are separated by a distance R. If the charge on the positively charged particle is doubled and the distance between them stays the same, the force will increase by a factor of ______.

a. 0.5 b. 1 c. 2 d. 4



1. (b) repulsive

Particles which have the same charge repel one another. Particles which have opposite charges attract one another.

2. (c) 2

The electric force between two charged particles is directly proportional to the charge of the particles. Therefore, if the charge of one of the particles is doubled, the electric force between the charges will double as well.

attraction (electric)

opposite charges pull towards one another

electric force the force between two charged particles that is directly proportional to the magnitude of the charges and inversely proportional to the distance between them

repulsion (electric)

like charges push away from one another

Key Terms


Energy

SC 12.2.3 Students will describe and investigate energy systems relating to the conservation and

interaction of energy and matter.


OBJECTIVE

PRACTICE

•Describe mechanical wave properties (speed, wavelength, frequency, amplitude) and how waves travel through a medium

The wavelength of a wave is how far it takes to repeat a cycle. (meters)The frequency of a wave is how many cycles it completes in one second. (Hertz = 1/second)The amplitude of a wave is how far a wave’s crest or trough is from its equilibrium point. (meters)

The speed of a wave can be found by taking the wavelength time the frequency. This allows you to find the distance per unit time the wave is covering. Mechanical waves need a medium to travel through. A medium is a substance or material which can propagate a wave. The only type of wave which does not need a medium to travel through is an electromagnetic wave.

1. If a wave completes 20 cycle in 5 seconds, what is its frequency?a. 2 Hertz b. 4 Hertz c. 6 Hertz d. 8 Hertz

2. Mechanical waves can travel through a vacuum (no matter).a. True b. False



1. (b) 4 Hertz

Frequency is the amount of cycles a wave completes in one second.

20 cycles / 5 seconds = 4 Hertz

2.(b) False

Mechanical waves need a medium to travel through.

amplitude (wave) height of the wavefrequency (wave) number of complete waves that pass a point per secondmechanical wave

propertiesfrequency, wavelength, and speed of a wave through a medium are related by the formula v=fλ (a.k.a. c = λν)

medium the substance that carries a wavewavelength distance between adjacent crests

Key Terms


OBJECTIVE

PRACTICE

•Recognize that the energy in waves can be changed into other forms of energy

The law of conservation of energy states that energy can not be created or destroyed. Therefore, when one type of energy is lost, another type of energy is gained. Energy from waves can be changed into other forms of energy. This is the case with electromagnetic radiation, which can be turned into electrical power.

1. Energy can be destroyed.

a. True b. False

2. Energy from waves can be converted into ___________ energy.

a. kinetic b. potential c. thermal d. All of the above



1. (b) False

Energy is transferred from one form to another, not created or destroyed.

2. (d) All of the above

Energy from waves can be converted to many types of energy.

Key Terms

forms of energy kinetic (electrical, heat, light, motion, and sound) and potential (chemical, gravitational, mechanical, and nuclear)

transformation of energy

energy can transfer from one form to another (e.g. nuclear to heat, chemical to mechanical, electrical to light )


OBJECTIVE

PRACTICE

•Recognize that light can behave as a wave (diffraction and interference)

Light can demonstrate qualities of both a wave and a particle. Therefore, it exhibits properties of diffraction and interference. Diffraction is the change in the directions and intensities of a group of waves after passing by an obstacle or through a slit whose size is approximately the same as the wavelength of the waves.Interference is the mutual effect on meeting of two wave trains that constitutes alternating areas of increased and decreased amplitude.

1. When light passes through a slit it is diffracted.a. True b. False

2. Light interference demonstrates its _______ nature.a. particle b. energy c. wave



1. (a) True

Light’s wave nature causes it to be diffracted when it passes through a slit.

2. (c) wave

Interference happens amongst waves, so light interference demonstrates its wave nature.

diffraction bending of light as it passes around the edge of an object

interference the effect of waves coinciding to create a new wave pattern

Key Terms


OBJECTIVE

PRACTICE

•Distinguish between temperature (a measure of the average kinetic energy of atomic or molecular motion) and heat (the quantity of thermal energy that transfers due to a change in temperature)

Thermal energy is measured by the kinetic energy of the particles. Temperature is the average kinetic energy and heat is the total kinetic energy. Temperature is independent of the amount of material and heat is dependent of the amount of material.The right box has more kinetic

energy, which means more thermal energy.

1. Which has the greatest amount heat? a. cup of water at 100oC b. bucket of water at 50oC c. swimming pool at 35oC

2. Which is hotter (higher temperature)? a. cup of water at 100oC b. bucket of water at 50oC c. swimming pool at 35oC



1. (c) swimming pool at 35oC

Heat is a measure of the total thermal energy in a substance. This includes both the kinetic energy of the particles and the total amount of particles (mass). Even though the average kinetic energy is lower, there is a lot more water in a swimming pool than in either a cup or bucket.

2. (a) cup of water at 100oC

Temperature (how “hot” something feels) is the average kinetic energy in a substance. The cup of water has fewer particles than both the bucket and swimming pool, but there is much more kinetic energy per particle due to the higher temperature. Even though the particles may have a higher kinetic energy, they will not be able to release much heat because there are fewer particles. Pouring cup of water at 100oC into a bucket of cold water may not raise the temperature of the water by much, but a bucket of warm water can raise the colder water much more because there is more water in the bucket of warm water.

heat the kinetic energy that flows between two samples of matter due to their difference in temperature

Key Terms


OBJECTIVE

PRACTICE

•Compare and contrast methods of heat transfer and the interaction of heat with matter via conduction, convection, and radiation

Conduction Direct contact Heat is transferred by collisions The man’s hands will gain energy because it is touching the hot iron directly.

Convection Transfer of heat in a fluid

Air is a fluid , the more energetic particles move from one location to another transferring heat (in currents).

The child is warming their hands in the air that has been heated by the campfire.

Radiation No matter needed Radiant energy can travel in the space between gas molecules, heat is transferred by electromagnetic radiation.

The earth receives radiant energy that travels through space from the sun. The heat from the fire is transferred to the hands by radiation because it can travel through the empty space between air molecules.

1. How is heat transfer by conduction different from convection and radiation?

2. Which type of transfer is used to fry an egg on an electric stove?

3. Which type of transfer is used to cook an egg in the microwave?



1. How is heat transfer by conduction different from convection and radiation? Conduction is transfer by direct contact, conduction would be transfer through a gas or liquid and radiation does not need any molecules.

2. Which type of transfer is used to fry an egg on an electric stove? The metal coil would directly touch the pan and the pan would be in direct contact with the egg, so conduction is the method of transfer.

3. Which type of transfer is used to cook an egg in the microwave? The microwave oven uses microwaves, a type of electromagnetic radiation to heat food, so the transfer is radiation. Notice that the air in the microwave does not heat up like a traditional convection oven.

Key Terms

conduction transfer of heat energy between heat substances that are in direct contact with one another

convection the movement of ensembles of molecules with gases and liquids

radiation heat transfer due to electromagnetic waves


OBJECTIVE

PRACTICE

•Recognize that the production of electromagnetic waves is a result of changes in the motion of charges or by a changing magnetic field

An electromagnetic wave is a wave of energy having a frequency within the electromagnetic spectrum and propagated as a periodic disturbance of the electromagnetic field. They are produced by a change in the motion of a charge or by a changing magnetic field.

1. Electromagnetic waves can be produced by a changing magnetic field.a.True b. False

2.Electromagnetic waves contain both an electric field and magnetic field component.a. True b. False



1. (a) True

Electromagnetic waves are produced by a change in the motion of a charge or by a changing magnetic field.

2. (a) True

Electromagnetic waves have both an electric and magnetic field component.

Key Terms

wave (electromagnetic)

a disturbance that travels through space as a result of changes in the motions of charges or changing magnetic field


OBJECTIVE

PRACTICE

•Compare and contrast segments of the electromagnetic spectrum (radio, micro, infrared, visible, ultraviolet, x-rays, gamma) based on frequency and wavelength

All electromagnetic radiation -- from radio waves to x-rays -- travel at the speed of light. In empty space this speed is approximately 300,000 kilometers per second!Each type varies from the other by the wavelength and the frequency of those waves. Radio waves have a long wavelength, and are not very frequent, gamma waves have a very short wavelength but are very frequent which gives them the strength to penetrate most objects.

1. X-rays have a ___________ wavelength as compared to microwaves.

a. larger b. smaller c. similar

2. ___________ have a high frequency as compared to ultraviolet waves.

a. Visible light waves b. Infrared waves c. gamma waves



1. X-rays have a smaller wavelength as compared to microwaves.X-rays and gamma rays are at the end of the spectrum that has small wavelengths; the frequency of those waves is much greater than the longer waves, like radio waves. X-rays are so energetic that they can travel through matter, breaking bonds as they go.

2. Gamma waves have a high frequency as compared to ultraviolet waves. Gamma waves have the smallest wavelength and the largest frequency. Ultraviolet waves are not as frequent and have less penetrating power through matter. (They can carry enough energy to enter your skin cells, whereas gamma can travel farther into tissue and is used to treat patients who have cancer.)

Key Terms

electromagnetic spectrum

a continuum of all electromagnetic waves arranged according to frequency and wavelength


OBJECTIVE

PRACTICE

• Recognize that nuclear reactions (fission, fusion, radioactive decay) convert a fraction of the mass of interacting particles into energy, and this amount of energy is much greater than the energy in chemical interactions

A chemical change involves changes in electron distribution in atoms. A nuclear change involves changes within the nucleus, commonly changes in the number of protons or neutrons. In every nuclear change, some of the mass is converted to energy and the energy is found using Einstein’s equation: E = mc2, where c is the speed of light (3 x 108 m/s). A common form of released energy is gamma radiation, a high frequency wave.

1. A radioactive isotope undergoes nuclear fission. The atomic number of the resultant particle(s) is always

a. smaller b. greater c. the same d. equal to 1

2. The amount of energy released from a nuclear reaction is directly proportional to a. type of decay b. mass change c. product isotope



1. (a) smaller

Nuclear fission involves the splitting of a nucleus. The resulting isotope(s) will always have a smaller atomic number because the initial nuclear broke into pieces, leaving fewer protons in each new isotope’s nucleus.

2. (b) mass change

The amount of energy released through mass defect (change in mass) is directly proportional to the amount of mass lost. According to Einstein’s equation (E = mc2), the more mass that is lost, the greater the energy released.

nuclear reactions reactions that convert a fraction of mass into energy (e.g. fission, fusion, radioactive decay)

Key Terms


OBJECTIVE

PRACTICE

•Interpret the law of conservation of energy to make predictions for the outcome of an event

The law of conservation of energy (1st law of thermodynamics) states that the energy in an isolated system is constant over time but it can change forms and locations. Knowing the amount of stored energy, we can predict the amount of energy given off or the amount of work done. One gram of explosive will always release the same amount of energy and the same falling apple from a given height will always release the same amount of energy.

1. The heat lost by one object in an isolated system must equal the heat ____ by another.

a. gained b. lost c. destroyed d. created

2. If a pendulum (image to the right) contains 100 J of potential energy when pulled back (1), the amount of kinetic energy at the bottom (3) of the swing must be (assume no friction)?

a. less than 100 J b. more than 100 J c. equal to 100 J



1. (a) gained

The law of conservation of energy states that energy can neither be created nor destroyed, but can change forms or position. If one object in an isolated system loses energy (heat) the other object must gain that energy (heat).

2. (c) equal to 100 J

The (potential) energy of the pendulum at the beginning must equal the kinetic energy of the pendulum at the bottom of the swing. The energy it took to raise the pendulum to the starting height would have been the same energy lost when it falls back to the starting position.

kinetic energy energy of motion

potential energy stored energy

Key Terms


OBJECTIVE

PRACTICE

•Identify that all energy can be considered to be either kinetic, potential, or energy contained by a field (e.g. electromagnetic waves)

Kinetic energy is the energy due to the motion of an object.Potential energy is stored energy due to an object’s position or composition.An object’s mechanical energy is the total of its potential energy and kinetic energy.Energy can also be contained in a field, such as electromagnetic waves.

1. As an object falls through the air, its mechanical energy _________.a. decreases b. increases c. stays the same

2. Energy due to an object’s position is its _________ energy.a. kinetic b. potential c. nuclear d. chemical



1. (c) stays the same

An object’s mechanical energy is the total of its potential energy and kinetic energy. As an object falls through the air, its potential energy decreases at the same rate its kinetic energy increases. Therefore its mechanical energy stays the same.

2.(b) potential energy

Energy due to an object’s position or composition is its potential energy.


OBJECTIVE

PRACTICE

•Identify endothermic and exothermic reactions

Chemical reactions typically involve a change in energy as they proceed. Heat is a common measure of energy change within a reaction. Those reactions which give off heat are called exothermic and those that gain heat are endothermic.

1. The combustion of wood is used as a fuel source for cooking. The combustion of wood is a type of _____________ reaction.

a. endothermic b. exothermic c. reversible d. nuclear

2. An endothermic reaction will have heat written into the equation as a a. reactant b. product c. catalyst



1. (b) exothermic

The combustion of wood releases heat which is absorbed by the food source. The combustion of any fuel source (hydrocarbon) involves the following reaction seen below. It is the conversion of the fuel (a reduced form of carbon) to a carbon dioxide and water (more oxidized forms) that releases the energy.

2. (a) reactant

An endothermic reaction requires the input of energy in order to drive the reaction. Heat would then be considered a reactant because it has to be put into the system.

endothermic reaction chemical reaction in which heat is absorbed

exothermic reaction chemical reaction in which heat is released

Key Terms

NeSA- Life Science

Structure and Function of Living Systems

SC 12.3.1 Students will investigate and describe the chemical basis of the growth, development, and

maintenance of cells.


OBJECTIVE

PRACTICE

•Identify the complex molecules (carbohydrates, lipids, proteins, nucleic acids) that make up living organisms

Carbohydrates- Include sugars (C6H12O6) and starches and are used for energy storage, and serve as building blocks. They are made of monosaccharides linked together.Lipids- (fats, oils, waxes, steroids) Are hydrocarbons that are used for energy storage, and to line cell membranes. They are made of fatty acids. Proteins- Are structural materials (hair/nails, muscle) , are enzymes (to increase reaction rates), and they act as carriers to facilitate getting large materials into cells. They are made of amino acids and have peptide bonds. Nucleic Acids -Are made from nucleotides which have 1 sugar (deoxyribose or ribose), 1 or more phosphate bases and 1 nitrogen base (A,T,C,G,U). They are molecules that store information as DNA or RNA.

1. What are the building blocks of carbohydrates?

2. Which molecule is used by cells for increasing reaction rates and is a component of the cell membrane?



1. Carbohydrates are made of simpler substances such as monosaccharides linking together to make larger molecules which are sugars and starches.

2. Proteins function in many different ways, they provide structure for the muscles, they transport materials across the cell membrane, they are enzymes which increase the rate of chemical reactions and they are active in the immune system as defense molecules.

Key Terms

carbohydrate molecule that is the major source of energy for an organism

lipid molecule that stores energy and is the main structure of cell membranes

nucleic acid building block of living organisms that passes genetic information from one generation to the next (e.g. DNA)

protein molecule needed by organisms for growth and repair


OBJECTIVE

PRACTICE

•Identify the form and function of sub-cellular structures that regulate cellular activities

Organelle Structure Function Organelle Structure Function

Cell Membrane Phospholipid bilayer- hydrophilic heads, hydrophobic tails, proteins embedded in surface

Semi-permeable membrane, it helps regulate the materials going into and out of the cell. (Osmosis/diffusion/facilitated diffusion/active transport

Endoplasmic Reticulum (RER and SER)

Large folded membrane outside of the nucleus which holds ribosomes (RER)

Site of protein synthesis and transport of newly made proteins

Cell wall (plants/bacteria)

Rigid wall which surrounds cell membrane

Provides structural support and helps prevent dehydration

Golgi Apparatus Folded membrane structure

Proteins are packaged here to be moved out of the cell

Chloroplasts (plants) A vesicle which holds chlorophyll

Chlorophyll is the pigment which absorbs sun’s energy for photosynthesis

Mitochondria Bean shaped organelle with folded layers inside

Site of Cellular Respiration ( ATP made here)

Nucleus Large membrane bound structure which holds DNA

Site of transcription of mRNA

Ribosomes Small organelles found free-floating and on ER

Site of protein synthesis

1. Which part of the red blood cell will allow water, oxygen, carbon dioxide, and glucose to pass through?

Because other substances are blocked from entering, this organelle can be described as:A perforated. B semi-permeable. C non-conductive. D permeable.

2. A cell from heart muscle would probably have an unusually high proportion ofA lysosomes. B mitochondria. C mRNA. D Golgi bodies.



1. Which part of the red blood cell will allow water, oxygen, carbon dioxide, and glucose to pass through? Cell Membrane (plasma membrane)

Because other substances are blocked from entering, this organelle can be described:B semi-permeable; Some substances (like water) flow into and out of the cell easily, some are too large, the concentration gradient does not favor what the cell requires or the molecules are charged so they must enter and leave through different types of proteins channels.

2. A cell from heart muscle would probably have an unusually high proportion ofB mitochondria, since the heart’s muscle cells are constantly contracting a lot of energy (in the form of ATP ) is required, so the heart has a large amount of mitochondria.

cell membrane thin barrier that surrounds all cells that controls what enters and leaves the cell

cell wall strong supporting layer around the cell membrane in some cells

chloroplast organelle found in some organisms that carries out photosynthesis

cytoplasm the fluid portion of a cell's interiormitochondria organelle that converts digested food into cellular energy

nucleus organelle that regulates the production of proteins and contains genetic material

organelle subcellular structureribosomes organelle that is the site of protein synthesis

vacuole organelle that is used to store materials


OBJECTIVE

PRACTICE

•Describe the cellular functions of photosynthesis, respiration, cell division, protein synthesis, transport of materials, and energy capture/release

Process OverviewPhotosynthesis converts light energy into the

chemical energy of sugars and other organic compounds

light + 6CO2 + 6H20 C6H12O6 + 6O2 Photosynthesis takes place in chloroplast

ATP and Sugar Production

Respiration Sugar is broken down to produce ATP

C6H12O6 + 6O2 6CO2 + 12H20 + energy (ATP)

Respiration occurs in mitochondria of all organisms

Cell Division Mitosis Cell Cycle: DNA duplicates and is divided between 2 cells before they divide.

For growth, repair and asexual reproduction

Protein Synthesis Proteins are assembled in ribosomes

Transcription-DNA is template for mRNA made in nucleus

Translation-amino acids created and linked by peptide bonds in ribosomes

Material Transport Concentration gradient: amount of materials inside and outside of cell

Diffusion: High to low (No energy) Osmosis: diffusion of water

Active Transport: Needs energy to move materials low to high or large molecules

Energy Capture/Release Metabolism: Cells need energy to do many processesATP

Energy comes in many forms (kinetic, potential)

Chemical potential is released using enzymes

1. Where does photosynthesis take place:a. Mitochondria b. nucleus c. chloroplasts d. membrane

2. During diffusion, when the concentration of molecules on both sides of a membrane is the same, the molecules will:



1. Photosynthesis occurs in the chloroplasts of the plant cells.

2. Diffusion is the random movement of molecules. When the concentration gradient is high there is a net movement of molecules from higher to lower until the concentration gradient is zero (concentration in and out of the cell is the same) at that point the molecules will continue to move across the membrane in both directions. The solution is isotonic at that point.

active transport cell transport that does require energy (e.g. endocytosis, exocytosis)

cellular respiration process that releases energy by breaking down food molecules, in the presence of oxygen

cellular transport the movement of materials into, out of, or within of a cellenzyme protein that speeds up biological reactions

metabolism set of chemical reactions in the cells of living organisms to sustain life

passive transport cell transport that does not require energy (e.g. Diffusion, osmosis)

photosynthesis process by which energy rich molecules are made from water and carbon dioxide in the presence of light

protein synthesis formation of proteins using information coded on DNAselectively permeable

property of biological membranes that allows some substances to pass across, while others cannot

Key Terms


OBJECTIVE

PRACTICE

•Describe how an organism senses changes in its internal or external environment and responds to ensure survival

Organisms are subjected to changing environments such as changing environmental temperatures. There are two ways to deal with this: metabolic process can slow down and they become sluggish and they can take measures to conserve metabolic heat and retain for parts that need it most.Homeostasis is regulated by feedback loops.

1. Use the flow chart to describe what happens when a person touches an object that is very hot.

2. The two body systems that regulate homeostasis are the:a) cardiovascular and respiratory systems b) cardiovascular and urinary systemsc) cardiovascular and endocrine systems d) nervous and cardiovascular systemse) nervous and endocrine systems



1. Stimulus: hot object on hand Thermoreceptors on hand receive the stimulus and send a message via the sensory nerve to the Central Nervous System (brain and spinal cord) that the tissue is in danger of receiving damage. The spinal cord relays a message to the motor neuron directing it to contract the muscle to remove the hand from the danger.The muscle contracts, moves the hand, thus creating the response to protect the individual.

2. The nervous and endocrine systems work together to create feedback loops that regulate hormones in the body.

Key Terms

stimulus any physical or chemical input that is sensed

NeSA- Life Science

Heredity

SC 12.3.2 Students will describe the molecular basis of reproduction and heredity.


OBJECTIVE

PRACTICE

•Identify that information passed from parents to offspring is coded in DNA molecules

A chromosome contains DNA, which is a molecule composed of nucleotides arranged into sequences called genes.

Reproduction involves passing genetic information (DNA) from parents to offspring. Asexual reproduction involves one parent and sexual reproduction involves two parents and the fusion of gametes.

1. A segment of DNA which influences traits in offspring is called a(n) a. nucleotide b. chromosome c. gene d. gamete

2. What cellular structure contains a large amount of genetic information that is passed to offspring through gametes or binary fission? a. chromosome b. nucleotide c. gene d. sperm



1. (c) gene

DNA contains genetic information is the form of nucleotide sequences, which is called a gene. The genes that an organism contains for a particular trait is called a genotype. The trait that is expressed in the organism is called a phenotype.

2. (a) chromosome

Chromosomes are condensed forms of DNA which also contain specific proteins called histones. During cell division or gamete formation, DNA is condensed from chromatin into chromosomes so that genetic information can be separated for reproduction.

DNA nucleic acid that contains all of the genetic instructions for an organism

inheritance passing of genetic material from parent to offspringtrait specific characteristic of an individual

Key Terms


OBJECTIVE

PRACTICE

•Describe the basic structure of DNA and its function in genetic inheritance

DNA is a polymer made from nucleotides in the form of a double helix. The two strands are formed from phosphates and ribose sugars. The “rungs” of the DNA are formed from complement pairing of the bases, A-T & G-C.

Genes are expressed into traits through protein synthesis. DNA is transcribed into mRNA which is translated into polypeptides, chains of amino acids.

1. In the DNA double helix structure, adenine is complementary based paired with a. adenine b. guanine c. cytosine d. thymine

2. During translation, mRNA is copied into a chain of amino acids. How many nucleotides code for a single amino acid? a. one b. two c. three d. four



1. (d) Thymine

DNA is a double helix consisting of four different nucleotides which are complementary based paired. Adenine pairs with thymine and cytosine pairs with guanine.

2. (c) three

Amino acids are coded for in a polypeptide from mRNA. There are 20 known amino acids and only four RNA nucleotides (adenine, guanine, cytosine & uracil). In order to code for all the amino acids, three nucleotides are used to code for the amino acids. These are called codons.

Key Terms

double helix the shape of DNA that resembles a spiral staircase or a twisted ladder

mitosis nuclear division in organisms that have a nucleus

nucleotidebuilding block of a nucleic acid; consisting of a sugar, phosphate, and a nitrogen base (e.g. adenine, guanine, cytosine, thymine)


OBJECTIVE

PRACTICE

•Recognize how mutations could help, harm, or have no effect on individual organisms

A mutation is a change in the nucleotide sequence of a DNA molecule. If the change in nucleotide(s) causes a change in the expressed protein, it can alter the protein and cause harm or it can cause a different phenotype which can be beneficial. If the mutation occurs in a sequence of DNA which does not affect the protein structure or the expression of the protein, the mutation has no effect. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that occur during meiosis or DNA replication.

1. A change in the sequence of amino acids within a gene is know as a. mutation b. transcription c. translation d.

expression

2. In order for a mutation to be harmful, it has to alter the expression of a. DNA b. a protein c. a chromosome d. a cell



1. (a) mutation

A change in the sequence of DNA is a mutation. There are different ways the sequence can be changed, such as; point mutations, deletions, insertions, inversions, translocation and duplications. All of these will alter the nucleotides which can lead to the expression of a protein.

2. (b) protein

Mutations that affect expression of a protein, either by altering the sequence of amino acids or affecting the regulation, can lead to either beneficial or negative effects. Those that produce a phenotype which helps the organism survive will be a beneficial mutation. Mutations which alter the protein that cause harm or death to the organism are considered negative effects.

mutation change in the genetic material of a cell

Key Terms


OBJECTIVE

PRACTICE

•Describe that sexual reproduction results in a largely predictable, variety of possible gene combinations in the offspring of any two parents.

During gamete formation, alleles on different chromosomes segregate independently, producing genetic variation. Random fertilization defines variations in gamete union.

1. How many alleles do most organisms contain for a specific trait? a. one b. two c. three d. four

2. A Punnett square (figure to the right) shows the possible production of a. gametes b. chromosomes c. mutations d. offspring



1. (b) two

For many traits an organism contains a paternal allele and a maternal allele, passed down during fertilization. Alleles are specific expressed forms of a gene. Alleles can be dominant or recessive, depending on their ability to influence the expression of a trait.

2. (d) offspring.

Independent assortment of chromosomes (alleles) and random fertilization are two forms of genetic variation. There is a probability associated with the formation of specific gametes and a probability associated with which gametes are involved in fertilization. These two factors (along with mutations) are what cause differences between organisms.

alleles alternate forms of a genegenotype genetic makeup of an organism

heterozygous having two different alleles for a particular genehomozygous having two identical alleles for a particular gene

meiosis the process of nuclear division that reduces the number of chromosomes in a cell by half

phenotype physical characteristics of an organismPunnett square model used to determine probabilities of a genetic cross

Key Terms

NeSA- Life Science

Flow of Matter and Energy in Ecosystems

SC 12.3.3 Students will describe, on a molecular level, the cycling of matter and the flow of energy

between organisms and their environment.


OBJECTIVE

PRACTICE

•Explain how the stability of an ecosystem is increased by biological diversity

Biodiversity is the distribution of genes, organisms or ecosystems in an area. Ecological stability describes the ability of an ecosystem to resist changes due to limiting environmental factors, such as the availability of light, water, space and required nutrients. Required nutrients are related to an ecosystem’s food web. A more diverse food web provides greater stability because it prevents large scale extinctions.

1. The greater number of species and differences between organisms increases biodiversity. a. true b. false

2. What roles do plants perform in a food web? a. 1st order consumers b. 2nd order consumers c. 3rd order consumers d. producers



1. (a) true

Biodiversity is measured by the number of different genes, organisms, species and ecosystems found in an area. As the variance in these factors increases, the biodiversity increases.

2. (d) producers

Plants function as producers in a food web, commonly the first trophic level. They take energy sources (typically sunlight) and raw materials in order to produce food for other organisms.

biological diversity the degree of variation of life forms within a given ecosystem

Key Terms


OBJECTIVE

PRACTICE

•Recognize that atoms and molecules cycle among living and nonliving components of the biosphere

Biogeochemical cycles show how specific elements or molecules move between different elements of the biosphere. Examples are water, nitrogen, carbon and phosphorus.

1. Which of the following does not comprise a biogeochemical cycle? a. carbon b. water c. light d. nitrogen

2. Most elements involved in biogeochemical cycles are recycled from dead organisms by a. consumers b. producers c. carnivores d. decomposers



1. (c) Light

Light is not cycled through living and nonliving components. Light is absorbed by photosynthetic organisms where the energy is incorporated to produce food.

2. (d)

Decomposers are organisms that use dead or non-living organic compounds as their food resource. These are commonly bacteria, fungi and various worms. These organisms convert non-usable organic sources into usable resources that can be re-incorporated by other organisms.

atom basic unit of matterbiogeochemical

cyclecycle by which materials necessary for organisms are circulated through the environment (e.g. water, carbon, nitrogen)

biosphere area on and around Earth where life exists

Key Terms


OBJECTIVE

PRACTICE

•Explain how distribution and abundance of different organisms in ecosystems are limited by the availability of matter and energy and the ability of the ecosystem to recycle materials

The biodiversity of an ecosystem is dependent upon limiting factors. These include availability to water, nutrients, sunlight, nesting space, shelter, predation pressures and temperatures. Organisms that can resist changes in limiting resources are tolerant. When limiting factors fall within the optimum tolerance range, population sizes increase.

1. Which of the following is NOT a limiting factor in determining an organism’s habitat? a. a source of water b. available food c. limited predation d. all are factors

2. What is the outcome when limiting factors are outside of tolerance range for an organism? a. extinction b. high reproduction rates c. maximum growth



1. (d) all are factors

All of the factors listed are limiting factors.

2. (a) extinction

When limiting factors lie outside of the optimum zone of tolerance, living conditions become difficult and an species’ reproductive success falls while death rates increase. This will lead to extinction.

biome a group of ecosystems that share similar climates and organisms

Key Terms


OBJECTIVE

PRACTICE

•Analyze factors which may influence environmental quality

Environmental quality measures the conditions of the environment as it relates to sustaining an ecosystem. Factors that are used to assess the environmental quality are air quality, water quality, waste, pollution, noise level, climate change and habitat conditions.

1. Which of the following is not considered an environmental quality factor? a. amount of rainfall b. high water nitrates c. minimal vegetation d. all are

factors

2. All environmental quality factors have tolerable limits which still are able to maintain life. a. true b. false



1. (d) all are factors

Any measureable factor in the environment which can affect the survivability of an organism or a species is considered an environmental quality factors.

2. (a) true

Environmental quality factors have been tested to see what the tolerant ranges are for many organisms. As long as the factor is within the tolerable ranges, life should be generally unaffected.

environmental quality the state of environmental conditions

Key Terms

NeSA- Life Science

Biodiversity

SC 12.3.4 Students will describe the theory of biological evolution.


OBJECTIVE

PRACTICE

•Identify different types of adaptations necessary for survival (morphological, physiological, behavioral)

Populations evolve, individuals cannot evolve. A population has continuity from generation to generation. The genetic makeup of a population may change over time. Genetic variation is necessary for evolution to occur. Adaptations occur over many generations. Individuals are being selected, ones with certain traits (and genes) reproduce and pass their genes to the next generation.Most biological structures have the ability to serve alternative functions. This does not imply that a structure was formed in anticipation of future use. Instead the organism solved it’s survival problems with what was available. Homologous structures are parts of organisms that have the same origin, but may not have the same function. Analogous structures are parts of different organisms with similar function, but not similar origins. Example: streamline body of the whale (mammal) and a shark.Some physiological adaptations include the evolution of a more complex nervous system, a closed circulatory system or mechanisms which have created a “warm-blooded” organism.A behavioral adaptation could be a behavior that enables an animal to better evade it’s predator.

Mimicry of leaves by insects is an adaptation for evading predators. This example is a katydid from Costa Rica.

1. The creosote bush is a desert-dwelling plant that produces toxins that prevent other plants from growing nearby, thus reducing competition for nutrients and water. Is this an adaptation and if so, name the type. A. No B. Yes, Behavioral C. Yes, Morphological structure D. Yes, Physiological

2. Is echolocation in bats is adaptation for catching insects?



1. D, The bush’s ability to produce these proteins which are toxins is a physiological adaptation.(Morphological structures describe body structure, namely shape and form. Over time the katydid’s leaf-like structure is a trait that has been selected for over many generations. )

2. Yes, echolocation is a behavioral trait, (but the fact that it requires a specific structure to have that ability would also be a morphological adaptation as well).

Key Terms

behavioral related to the way something actsmorphological the form or structure of somethingphysiological related to the way something functions


OBJECTIVE

PRACTICE

•Recognize that the concept of biological evolution is a theory which explains the consequence of the interactions of: (1) the potential for a species to increase its numbers, (2) the genetic variability of offspring due to mutation and recombination of genes, (3) a finite supply of the resources required for life, and (4) the ensuing selection by the environment of those offspring better able to survive and leave offspring.

Darwin noticed that people could determine how animals look, how they behave as well as characteristics by “artificial selection”. He noticed that there were different characteristics that people would chose from to have mild-mannered pets, strong work animals or even nice looking pigeons. When he went on his voyage he thought that if people can select for favorable traits and those selected traits would be passed down to offspring, why couldn’t nature do the same thing? He noticed a few principles: more individuals would be born than could actually survive, there was a variety of characteristics present in each population, and the earth is dynamic (changing). Darwin who was a naturalist collected finches and when they were examined he noticed all of the different types. The islands where they were collected from had a changing climate over the years and at some periods, there was drought, and scarcity of resources so the birds who were better suited to get food (according to their beak’s makeup) would survive and pass that trait on to their offspring.

1. Which of the following statements is true about Charles Darwin? a) He believed that evolution was due to the inheritance of acquired characteristics.b) He supported Lamarck's explanation of how evolution occurred.c) He understood that the variation that exists in natural populations of plants or animals is the result of repeated mutations.

d) none of these2. Through careful observation, Charles Darwin came to understand that: a) populations of plants and animals in nature most often

consist of individuals that are clones of each other b) those individuals whose variation gives them an advantage in staying alive long enough to reproduce are more likely to pass their traits on to the next generation c) populations of a species that become isolated from others by adapting to different environmental niches quickly become extinct d) all of the above



1. The answer is NONE of these: Darwin only knew there was variation among individuals and he hypothesized that nature

selected individuals with favorable traits which then would have accumulated over time. He did not believe as Lamarck did that individuals could gain a characteristic and pass it on to their offspring. At this point, there wasn’t any work on mutations or molecular analysis that he would have known about.

2. B is correct:If an individual has a trait that allows it to get more food or to avoid being killed by predators or illness, it will have a greater chance of reproducing. As a result, more of the next generation will inherit the genes for the advantageous trait.

biological evolution descent with modification of organisms from common ancestors

genetic variability tendency of individual genetic characteristics in a population to differ from one another

recombination formation of new and different sets of chromosomes or genes

Key Terms


OBJECTIVE

PRACTICE

•Explain how natural selection provides a scientific explanation of the fossil record and the molecular similarities among the diverse species of living organisms

Variation is a key concept in evolution, it comes from different places and it recorded in the fossil record.Mutations are permanent, random chemical changes in the DNA molecule that pare passed on to offspringVariation from recombination can occur more quickly than variation due to random mutations. This deals with sexual reproduction. Crossing over, independent assortment, and the combination of genes from two individuals all create genetic variation.Variation from migration when organisms move from one population to another they introduce new genes into the population or remove genes when individuals leave. Some examples include body shapes and colors, chromosomal variations and protein variations.

This is an example of natural selection, the population of moths changed as the industrial revolution affected the trees, changing which variety of moths was most easily seen by predators.

1. The example of the peppered moths living near English industrial cities demonstrates that: a) a change in an environment can result in the evolution of species living there b) evolution occurs so slowly that it is not possible to determine that it has happened in less than a million years c) the environment near these cities has always favored dark colored moths

2. Charles Darwin concluded that the 13 species of finches on the Galápagos Islands: a) were identical to 13 finch species in northwestern South America 600 miles to the east b) probably evolved from one ancestral South American species



1. A. a change in an environment can result in the evolution of species living there .

Although this does not show evolution over a long period of time, the moths that were studied and how the population changed is a good example of how natural selection can occur over a relatively short time span.

2.B He surmised that the Galápagos finches had evolved from a species from the mainland.

He believed that the birds migrated to different islands, each with different food sources and climates, and that nature selected for survival varieties best suited to exploit them.

fossil record collection of preserved organisms or their traces stored in Earth

natural selection process by which organisms that are most suited to their environment survive and reproduce most successfully

Key Terms


OBJECTIVE

PRACTICE

•Apply the theory of biological evolution to explain diversity of life over time

Individuals of a species vary, some variations are heritable. More individuals will be produced than the environment can support, so individuals are forced to compete for resources. Individuals with favorable traits (and genotypes) will survive, reproduce and pass those favorable traits to the offspring.Over time environments will change and favor different traits, but an entire population will not likely be “selected out”. Gene pools will vary, thus there exists great diversity of organisms over time.

1. Earth has undergone some catastrophic changes from time to time. Which of these most likely explains why life on Earth continued following these catastrophes?A.Dominant species had a slow mutation rate. B. Many species filled the same niche.C. A strong species had many different characteristics. D. A wide diversity of species existed.

2. If a paleontologist finds fossils of many different species existing in the same area at approximately the same time, the paleontologist can conclude that the ecosystem in this area had a high degree ofA climatic variation. B episodic speciation. C biological diversity. D geographic isolation.



1. Although there have been at least 5 mass extinctions, because there is so much variation among individuals some organisms have been able to survive great environmental change.

2. Many different types of fossils indicate a great deal of biological diversity.

NeSA- Earth & Space Science

Earth in Space

SC 12.4.1 Students will investigate and describe the known universe.


OBJECTIVE

PRACTICE

•Describe the formation of the universe using the Big Bang Theory

The Big Bang Theory states that 13.7 billion years ago the universe was extremely hot and dense. At that point it began to expand and cool rapidly, which eventually led to the formation of our universe as we now know it. This sudden, rapid expansion is known as the “Big Bang”. Two of the primary sources of evidence that support the Big Bang Theory are the CMB (Cosmic Microwave Background) and the current expanding nature of our universe.

1. The approximate age of the universe is __________ old.a. 4.7 million years b. 4.7 billion yearsc. 13.7 million years d. 13.7 billion years

2. The universe is currently ______.a. contracting b. expanding c. none of the above


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1. (d) 13.7 billion years old

The Big Bang Theory shows that the universe is 13.7 billion years old. Our solar system is 4.7 billion years old.

2. (b) expanding

The Doppler effect shows that the universe is currently expanding.

Key Terms

big bang the prevailing theory that the universe began as one mass that then expanded into the state of the current universe


OBJECTIVE

PRACTICE

•Recognize that stars, like the Sun, transform matter into energy by nuclear reactions which leads to the formation of other elements

Stars have fusion reactions occurring within them that lead to the formation of new elements and release a tremendous amount of energy. Fusion is the process by which two small atoms combine to form a bigger atom and release energy.

All elements with an atomic number equal to or less than iron (26) are formed within fusion reactions in stars. Elements with atomic numbers greater than iron are formed within supernovae.

1. The process happening within the sun that provides the energy for our solar system is known as ___________.

a. fusion b. fission c. combustion d. oxidation

2. Elements are formed within __________.a. planets b. black holes c. comets d. stars

Standard-SC 12.4.1.b

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1. (a) fusion

Fusion reactions within our sun produce the energy the sun provides.

2.(d) stars

Elements are formed within the fusion reactions occurring within stars.

convection heat transfer in a fluid by the circulation of currents due to differences in density

Key Terms


OBJECTIVE

PRACTICE

•Describe stellar evolution

All stars start out as a collection of dust and gas known as a nebula. As gravity pulls the matter closer together eventually hydrogen begins to fuse at its core. Stars which fuse hydrogen at their core are called “main sequence stars”. When a star runs out of hydrogen, it becomes a red giant. Red giants eventually collapse due to gravity. The star then becomes either a white dwarf, neutron star, or black hole depending on its amount of mass.

1. Stars which burn hydrogen at their core are called __________.a. black holes b. red giantsc. white dwarves d. main sequence stars

2. What force causes stars to form?a. Friction b. Heat c. Gravity

Standard-SC 12.4.1.c

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1. (d) main sequence stars

Main sequence stars, like our sun, are fusing hydrogen at their core.

2. (c) gravity

The force of gravity is what causes gas and dust to form a nebula and eventually a star.

stellar evolution sequence of changes that occurs in a star as it age; this process is driven by gravity due to mass and pressure due to nuclear fusion

Key Terms


Earth Structures and Processes

SC 12.4.2 Students will investigate the relationships among Earth's structure, systems, and processes.


OBJECTIVE

PRACTICE

•Recognize how Earth materials move through geochemical cycles (carbon, nitrogen, oxygen) resulting in chemical and physical changes in matter

Elements are neither created nor destroyed, they are merely cycled through different earth systems.

As elements move through geochemical cycles, they influence the matter they interact with, which can cause changes to the environment around them.

1. Which of following spheres is carbon present in?a. Biosphere b. Atmosphere c. Lithosphere (Geosphere) d. All of the

above

2. The burning of fossil fuels results in higher levels of _______ in our atmosphere.a. carbon dioxide b. oxygen c. nitrogen d. All of the above


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1. (d) All of the above

Carbon is found in all of the major earth systems.

2. (a) carbon dioxide

The burning of fossil fuels leads to higher levels of carbon dioxide in our atmosphere.

geochemical cycles

the movement of elements between Earth's land, water, atmosphere, and living things

Key Terms


OBJECTIVE

PRACTICE

•Describe how heat convection in the mantle propels the plates comprising Earth's surface across the face of the globe (plate tectonics)

Plate tectonics is the currently accepted theory which helps explain continental drift, seafloor spreading, earthquakes, and volcanism. Convection currents in the mantle move “plates” across the earth’s surface. The convection currents are driven by radioactive decay in the core of the earth. This plate movement is the reason behind the phenomenon mentioned previously.

1. The earth’s continents have always been in the same location that we see them today.

a. True b. False

2. Plates on the surface of the earth are constantly being ________.a. created b. destroyed c. both created and destroyed



1. (b) False

Plates are constantly moving, due to the convection currents in the earth’s mantle. Therefore, the continents are constantly moving as well

2. (c) Both created and destroyed.

Plates are created at divergent boundaries.

Plates are destroyed at convergent boundaries.

convection heat transfer in a fluid by the circulation of currents due to differences in density

Key Terms


OBJECTIVE

PRACTICE

•Evaluate the impact of human activity and natural causes on Earth's resources (groundwater, rivers, land, fossil fuels)

Natural causes have a major impact on Earth’s resources. As humans we have adjusted to these throughout our existence. Humans also have a major impact on the Earth’s resources. Many of our natural resources have been polluted to the extent that we can no longer use them. Countries have laws and regulations in place to protect our resources. Renewable and non-renewable energy sources must be protected so that future generations can use them as well.

1. Which resource is renewable?a. coal b. natural gasc. solar d. uranium

2.Which resource(s) contributes to the rising level of carbon dioxide in our atmosphere?a. coal b. gasoline c. oil d. all of the above



1. (c) solar

Coal, natural gas, and uranium are all nonrenewable resources that we have a limited amount of on earth.

2. (d) all of the above

All of the listed options are fossil fuels. The burning of fossil fuels leads to a higher concentration of carbon dioxide in our atmosphere.

Key Terms

conservation the careful use of natural resources including preservation, protection, or restoration

fossil fuels a nonrenewable energy source from the remains of organisms from a former geologic age that can be used as fuel (examples include coal, oil, and natural gas)

groundwater water that is beneath Earth's surface


Energy in Earth's Systems

SC 12.4.3 Students will investigate and describe the relationships among the sources of energy and their

efforts on Earth's systems.


OBJECTIVE

PRACTICE

•Describe how radiation, conduction, and convection transfer heat in Earth's systems

Radiation is transferred from the sun to the earth. Some of radiation is absorbed by the atmosphere and lithosphere. Some of it is reflected back into space. Convection occurs in the earth’s atmosphere, oceans, and mantle. These currents have a direct influence on the weather we experience. Conduction transfers heat wherever particles are colliding. In all cases heat is transferred from areas of high heat to areas of low heat

1. Which process transfers solar energy to Earth?a. conduction b. convectionc. induction d. radiation

2.Which process is the primary cause of energy transfer within the earth’s oceans?a. conduction b. convectionc. induction d. radiation



1. (d) radiation

Radiation for the sun travels to earth in the form of photons.

2. (b) convection

Convection currents transfer heat through the flowing of a fluid.

conduction transfer of heat energy between heat substances that are in direct contact with one another

radiation heat energy transfer due to electromagnetic waves

Key Terms


OBJECTIVE

PRACTICE

•Identify internal and external sources of heat energy in Earth's systems

Energy is constantly being transferred within Earth’s systems from both internal and external sources. The sun is the source of external energy; decay of radioactive isotopes and gravitational energy from the earth's original formation are sources of internal energy.

1. The atmosphere gains most of its heat energy from the ____________.a. oceans b. sun c. Earth’s core

2. The mantle gains most of its heat energy from the __________.a. oceans b. sun c. Earth’s core



1. (b) sun

Radiation from the sun is absorbed by our atmosphere.

2. (c) Earth’s core

Radioactive isotopes in the earth’s core provide the heat energy that drives the convective currents within the earth’s mantle.


OBJECTIVE

PRACTICE

•Compare and contrast benefits of renewable and nonrenewable energy sources

Renewable energy resources are resources that we will not run out of due to overuse. Nonrenewable resources are resources that we have a fixed amount of on earth that will eventually run out over time. Currently, most of the energy in the United States come from nonrenewable resources. Transferring to renewable energy resources is costly and at times inefficient.

1. Most of the energy in the United States comes from renewable resources.a. True b. False

2. Which type of resource is a renewable resource?a. Hydroelectric b. Petroleumc. Coal d. Natural gas



1. (b) False

Most of the energy in the United States comes from non-renewable resources.

2.(a) Hydroelectric

Coal, petroleum, and natural gas are all examples of non-renewable resources.


OBJECTIVE

PRACTICE

•Describe natural influences (Earth's rotation, mountain ranges, oceans, differential heating) on global climate

Natural influences play a major role on global climate. The earth’s tilt on its axis causes differential heating, which is the reason why we have seasons in Nebraska. Ocean currents can bring milder climates to regions far from the equator. Mountain ranges can cause areas of arid climate due to a phenomenon known as “rain shadow”.

1. What causes seasons on Earth?a. distance from the sun b. oceansc. the earth’s tilt on its axis d. none of the above

2. Some areas of the Earth receive more direct sunlight than others. This Is known as _____.a. heat indexb. sunlight inequality c. differential heating



1. (c) the earth’s tilt on its axis

The earth’s tilt on its axis causes some regions to receive more direct sunlight at different parts of the year, causing seasons.

2. (c) differential heating


Earth's History

SC 12.4.4 Students will explain the history and evolution of Earth.


OBJECTIVE

PRACTICE

•Recognize that in any sequence of sediments or rocks that has not been overturned, the youngest sediments or rocks are at the top of the sequence and the oldest are at the bottom (law of superposition).

When sediments are deposited they are originally in a horizontal position. Over time new sediments are deposited on top of older ones. Therefore, when you look at a cross-section of a rock deposit, the youngest rocks are at the top and the oldest are on bottom. This is known as the law of superposition.

1. In the diagram at right, which rock formation is oldest?a. A b. B c. C d. D

2. In the diagram at the right, which rock formation is 2nd oldest?a. A b. B c. C d. D



1. (a) A

A is on the bottom of the cross-section, and therefore is the oldest rock formation. D has cut through A, making it younger.

2. (b) B

B is directly on top of A, making it the second oldest rock type.


OBJECTIVE

PRACTICE

•Interpret Earth's history by observing rock sequences, using fossils to correlate the sequences at various locations, and using data from radioactive dating methods

Earth’s history has been pieced together through both relative age dating and absolute age dating. Relative age dating uses the law of superposition, fossil comparison, and comparative rock dates. These methods allow scientists to sequence rocks and fossils in relation to each other. Absolute age dating uses half-lives of known isotopes to determine the absolute age of the fossil or rock formation.

1. After two half-lives, how much of an isotope is left?a. 0% b. 25% c. 50% d. 75%

2. What type of dating could tell us that an object is 2.5 million years old?

a. Relative age dating b. Absolute age dating



1. (b) 25%

Each half-life results in half of the present parent isotope decaying into the daughter isotope.

After one half-life there is 50% of the parent isotope left.

After two half-lives there is 25% of the parent isotope left.

2. (b) Absolute age dating

Absolute age dating allows us to calculate a specific age for an object.

fossil correlation a determination of the relative age of rock layers reached by studying fossils

radioactive dating the method of calculating the absolute ages of rocks and minerals that contain radioactive isotopes

Key Terms


OBJECTIVE

PRACTICE

•Compare and contrast the physical and biological differences of the early Earth with the planet we live on today

The conditions on early Earth were very different than what we live in today. The early atmosphere had very little oxygen and there were no oceans. The surface was covered by magma and there was no life present. As the earth cooled, water vapor in the atmosphere fell as rain and formed the oceans. Early plant-like life organisms called cyanobacteria used photosynthesis to produce nutrients they needed to survive, and gave off oxygen as a waste product. Today’s earth contains 21% oxygen in the atmosphere, life which relies on that oxygen, oceans, and a climate conducive to life for many organisms. All of these were not true for early Earth.

1. Oceans have been present for the entire history of Earth.a. True b. False

2. The early Earth had an atmosphere composed primarily of oxygen.a. True b. False



1. (b) False

Oceans formed after the earth had cooled and water vapor was cool enough to condense on the surface.

2. (b) False

The early Earth atmosphere contained very little oxygen.

nesa- inquiry, the nature of science, and technology abilities to do scientific inquiry sc 12.1.1...

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