taks objective i: nature of science. what is science? scientists use observations (process of...

TAKS Objective I:Nature of Science

What is Science?

• Scientists use observations (process of gathering information by using the senses) to gather data. They then use the data to make inferences (a logical interpretation of the data based on past experiences).

• Practice…

• _____ There are 2 doors.

• _____ The people are fighting because someone ate their cookies.

• _____ One door is closed.

• _____ They are hitting each other hard.

• _____ Glass is broken.

Determine in the picture if it is an observation (O) or an inference (I)

O

O

O

I

I

Steps to Experimental Scientific Investigation (The Scientific Method):

• 1. Observe – make an observation of the world around you. There are two kinds of observations:

– Qualitative observation – descriptive observation

• Ex: The plant is a dark green.

– Quantitative observation – a numerical observation.

• Ex: The flask contains 12.45 ml. There are 4 pennies.

• Which kind of observation? Let’s practice!

Determine if the statement is qualitative (A) or quantitative (B).

• _____ The sky is blue.• _____ There are 4

clouds.• _____ There are 3

hills.• _____ The first hill is

small.• _____ The clouds are

small.• _____ There are a

total of 38 birds.

A

B

B

A

A

B

• 2. Ask a question – based on your observation, ask a question to investigate.

• 3. Research - Look in books, journals and the internet to make additional observations and research about the questions you made from your observation.

• 4. Formulate a hypothesis: - Propose a scientific explanation to the question being observed and researched. The statement must be testable. (“Which is best?” does not lend itself to being tested). At the end of the investigation, you will either accept or reject your hypothesis.

• 5. Perform a controlled experiment - Develop and use the experimental design to test your hypothesis. Whenever possible, the hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged, or controlled.

Testing fertilizers on plant growth? Keep all other factors constant!

– Variables: Factor being tested• Controlled- Variables that are kept

constant• Independent- Variable being manipulated

(in a graph found on the x-axis or the horizontal axis)

• Dependent- Variable that responds (in a graph found on the y-axis or the vertical axis)

A way to remember variables

Dependent

Responding

Y - axis

Manipulated

Independent

X - axis

• 6. Observe again - Collect data (measurements) and perform analysis on the data using graphs and charts

• 7. Draw conclusions - State whether or not the evidence supports the hypothesis based on your data and analysis.

– Please notice that we do not prove hypotheses! Proof exists when the chance for error is 0. There is always some chance for error (no matter how small it is) and this existence of chance error means we cannot prove anything in true, honest, science.

bar graphstudent height

168 cm

pie chart

elements that make up living things (& their percentages)oxygen

line graph

temperaturetimex-axisy-axis

temperature of water as it is heated

The reason for wafting or fanning a small amount of chemical vapors toward the nose as a means to detect odors in a test tube is to —

A avoid experimental error from excessive loss of mass of reactants or productsB avoid splashing chemicals into the face of any personC protect the respiratory tract against potentially harmful vaporsD determine the relative strength of the odor before smelling directly

Bio/IPC 1A – Demonstrate safe practices during field and laboratory investigations.

Laboratory equipment is cleaned and properly stored after use primarily so that —

A chemical products can be measured and recorded as data

B time is saved in setting up the next experiment

C toxic materials can be kept in the laboratory

D the possibility of contamination in the laboratory is minimized


The ingredients described above are used to make a bonding agent. The most important safety precaution to take when applying this bonding agent is to —

F dry it with a small flame

G work in a well-ventilated area

H cover the work area with newspaper

J wear a lab coat


A safety checklist for this activity should include the presence of a proper fire extinguisher and all the following items except a —

A fire blanket

B receptacle for broken glass

C laboratory apron

D squeeze bottle


Powerful PlanktonThe U.S. Naval Research Laboratory has created an experimental marine fuel cell that could produce enough electricity to power ocean-monitoring devices. This fuel cell runs on seawater and sediment, with the help of plankton. Some plankton on the surface of ocean sediments use dissolved oxygen to break down organic matter, releasing energy; this is an aerobic process. The plankton in the deeper sediments break down organic matter without using oxygen; this is an anaerobic process. These two processes create a difference in voltage between the surface of the sediment and the sediment farther down in the seabed. The voltage difference can be used to produce electricity-up to 5.0 x 10 – 2 watts of power. Energy supplied by this type of fuel cell can be obtained as long as there is organic matter in the sediment.

Which safety precaution should be observed while analyzing sediment from a marine aquarium? A Wear rubber glovesB Use a fume hoodC Avoid using glasswareD Have a fire extinguisher nearby


In what part of this process should safety precautions be planned?

F QG RH SJ T


Which of these is a hypothesis that can be tested through experimentation?

F Bacterial growth increases exponentially as temperature increases.G A fish’s ability to taste food is affected by the clarity of aquarium water.H Tadpoles’ fear of carnivorous insect larvae increases as the tadpoles age.J The number of times a dog wags its tail indicates how content the dog is.

Bio/IPC 2A – Plan and implement investigative procedures including asking questions, formulating testable hypotheses, and selecting equipment and technology.

Which of the following pieces of equipment would be most appropriate for measuring the volume of a marble?


Objects of the same mass but of different sizes and shapes were dropped from a given height. Their rates of free fall were measured and recorded. Which of the following is most likely the question this experiment was designed to answer?

F How does height affect the force of gravity?G How does gravity affect objects of different densities?H How do mass and weight affect falling objects?J How do size and shape affect an object’s rate of free fall?


Which lab setup would be appropriate to use in heating 100 mL of water to the boiling point?

A A 10 mL test tube held above a Bunsen burner

B A 200 mL beaker placed on a hot plate

C A thermal coil inside a 100 mL cylinder

D A sealed 300 mL flask in a warm-water bath


In experiments, a benefit of larger sample sizes would be more —

A variables

B representative data

C time per group

D control groups


The following boxes represent a field. Which pattern for collecting 10 samples would provide the best data for identifying the types of plants in a field?


An engineer has created a new engine for race cars. It is necessary to know which fuel mixture will allow the engine to run at its peak performance. Which experimental design is best for this investigation?

F Use one fuel mixture on the engine and measure its performanceG Use one fuel mixture on many types of engine and measure their performanceH Use various fuel mixtures on the engine and measure its performanceJ Use various fuel mixtures on many types of engines and measure their performance


Which equipment is most useful when measuring the two environmental changes mentioned above?

F Barometer and voltmeter

G Light meter and barometer

H Voltmeter and thermometer

J Thermometer and light meter


Which of the following is most useful in determining the kinetic energy of a 50 g battery-powered car traveling a distance of 10 m?

A Beaker

B Voltmeter

C Thermometer

D Stopwatch


Which of the following will allow measurement of a liquid’s volume with the greatest precision?

A 50 mL cylinder graduated in 1 mL increments

B 100 mL cylinder graduated in 0.5 mL increments

C 100 mL cylinder graduated in 1 mL increments

D 200 mL cylinder graduated in 5 mL increments

Bio/IPC 2B – Collect data and make measurements with precision.

Which of the following procedures should be used in finding the mass of crystals?

A Pour the excess crystals back into the original containerB Put the crystals on the outer part of the balance pan for massingC Pour wastes down the sink with plenty of waterD Use weighing paper on the balance pan


What volume should be reported for the solution in this graduated cylinder?

F 64.0 mLG 56.2 mLH 56.0 mLJ 50.6 mL


The cloud conditions above are typical of locations near a warm front. According to these data, what are the most likely sky conditions for Waco?

A Cirrus clouds

B Altostratus clouds

C Stratus clouds

D Clear skies


The chart shows the density of seawater samples collected from the Gulf of Mexico by four different groups. Which group’s data are most precise?

A Group 1

B Group 2

C Group 3

D Group 4


During a severe drought a dry lake was explored for fossils. The diagram represents the fossils uncovered and the layers they were in. According to this information, this area was once a —

A forest that was replaced by a freshwater lakeB freshwater lake that was replaced by a desertC saltwater sea that was replaced by a forestD freshwater lake that was replaced by a forest

Bio/IPC 2C – Organize, analyze, evaluate, make inferences, and predict trends from data.

According to the graph, about how much hemoglobin would be saturated at an O2 pressure of 7.3 kPa?

A 32%

B 67%

C 89%

D 92%


Observing an approaching thunderstorm and using a stopwatch, a student finds that it takes 8.40 seconds for thunder to be heard after a lightning bolt strikes. The student has learned that it takes 3.0 seconds for sound to travel 1000 m. How far away is the storm?

F 119 mG 185 mH 2800 mJ 8400 m


From 1942 to 1945, U.S. nickels were made of an alloy that contained 35% silver, 9.0% manganese, and the rest copper, by mass. If one of these nickels has a mass of 5.0 grams, what is the mass of the copper?

A 0.5 gB 1.8 gC 2.2 gD 2.8 g


The graph shows the distance traveled by a vehicle over a certain period of time. Which segment of the graph shows the vehicle moving with the greatest speed?

A LB MC ND O


The graph shows the percentage of hemoglobin that combines with carbon monoxide (CO) at various concentrations. Exposure to 400 parts per million of CO in air can cause people to experience nausea and a throbbing headache. According to the graph, about what percentage of hemoglobin is bound to CO at a CO concentration of 400 parts per million?

A 25%B 35%C 40%D 55%


The table shows the atomic radii of some elements in Periods 1 through 4 of the periodic table. Which inference can be made from this information?

F Atomic radii decrease from left to right.G Atomic radii increase from bottom to top.H Atomic radii decrease from right to left.J Atomic radii double from top to bottom


In which general direction do rivers flow in this watershed?

F North

G West

H Northwest

J Southeast


The graph shows mercury levels found in sediments, prey animals, and adult shorebirds in a bay along the Gulf Coast. Which inference can best be drawn from these data?

F Mercury levels are elevated by the presence of shorebirds.G Mercury concentrations are highest in shorebirds.H Mercury is produced by sediments.J Mercury assures the survival of prey animals.


Which conclusion is best supported by these data?

F Earth’s surface is composed mostly of silicon and calcium.G Oxygen is closer to Earth’s surface than aluminum.H There is more aluminum than calcium at Earth’s surface.J Silicon is much heavier than iron at Earth’s surface.

Bio/IPC 2D – Communicate valid conclusions.

Ten different types of culture media were inoculated with the same strain of bacteria and incubated at the same temperature. Nine of the cultures grew. Which of these conclusions can be drawn from this information?

F The media used in the experiment are all capable of sustaining bacterial growth.G The temperature varied greatly during the experiment.H Only the culture that failed to grow bacteria was inoculated properly.J One of the media lacked the nutrients needed for the bacteria to grow.


Which conclusion about the frogs is supported by these data?

A Four frogs out of ten preferred the green area.

B The frogs randomly moved into the colored areas.

C Most frogs tended to avoid the red area.

D Most frogs preferred the color blue.


In an investigation 10,000 dung beetles were examined for the presence of parasites. The data showed that about 5% of the beetles had parasites. The results are —

F invalid because only dung beetles were examinedG unsupported because the parasite population was smallH erroneous because more beetles should have had parasitesJ valid because the sample size was sufficient for accuracy


A student prepared this graph of tornadoes reported over a 50-year period in a midwestern state. Which statement is supported by these data?

A Tornadoes are less frequent in the morning.

B Darkness increases the strength of tornadoes.

C Tornadoes occurring at night are brief.

D The probability of a tornado is the same throughout the day.


These data show how the mass of an undisturbed beaker of alcohol varied during a class period. Which of the following is the best conclusion that can be made about the investigation?

A The beaker absorbed moisture from the air.B A chemical change occurred in the beaker.C The beaker experienced a change of state.D Some material evaporated from the beaker.


Certain chemicals in the diet of moth larvae seem to influence the early development of the moths’ wings. Careful observation of developing pupae could result in —A data to verify the hypothesisB changes to the conclusionC a conclusion about the moths’ eggsD development of a new moth species

Bio/IPC 3A – Analyze, review, and critique scientific explanations, including hypotheses and theories, as to their strengths and weaknesses using scientific evidence and information.

As temperature drops to the dew point, clouds form in the atmosphere, and dew forms on ground surfaces. A scientist proposes that adding more water molecules to the atmosphere will change the dew point. This proposal is —

F an invalid observationG a valid hypothesisH an invalid problemJ a valid conclusion



In a movie, meteoroids make several microscopic holes in a pressurized cabin in the weightless environment of a spaceship. The astronauts search for the holes by spraying water droplets from a container. If this were an actual situation, what effect should be expected?

F The drifting water droplets float to the location of the holes.G After falling to the floor, the water forms a stream leading to the holes.H The water droplets form a large sphere of water that moves away from the holes.J Pumping the trigger on the spray container increases the air pressure in the cabin

This statement is a poor hypothesis because it is not —

A a question

B testable

C observable

D a comparison



The graph shows data for botulism, a form of food poisoning. The conclusion in the box is based on these data. Which of the following is the best reason this conclusion may be unreliable?

A The greatest number of reported botulism cases was 50.

B The number of reported botulism cases remained relatively constant from 1988 to 1995.

C More botulism cases were reported in the 1980s than in the 1990s.

D The number of reported botulism cases decreased after 1994.

The information above could be used most effectively in arguing against which of these proposals?F Adding chemicals to a local water supplyG Permitting a water well to be drilled in a state parkH Limiting the use of waterways for recreationJ Paving a meadow to create a parking area


Pain medications can be made as powders or tablets. The powders tend to work faster than tablets with the same ingredients because powder —

F dissolves faster in solution than a single tablet

G has more total mass than a single tablet

H travels through the bloodstream more easily than a tablet

J is easier to swallow than tablets

Bio/IPC 3B – Draw inferences based on data related to promotional materials for products and services.

The owner of a pet store assures a customer that if she buys only one female hamster, she will not need to worry about the hamster having offspring, because there will be no male with which the female can breed. What possibility is the pet-store owner overlooking?

F The hamster could be infertile.G The sex of the hamster could change.H The hamster could be pregnant.J The hamster could be a twin.


According to the information above, which of these is responsible for the decrease in the black-footed ferret population?

F Competition with prairie dogs for resourcesG Reduced numbers of prairie dogsH Activity of research institutesJ Development of managed wildlife areas


Which statement above makes the most valid argument in favor of receiving the flu vaccine?

F Statement 1

G Statement 2

H Statement 3

J Statement 4


Greenhouse emissions from cars may contribute to global warming. Cars with better gas mileage emit smaller amounts of greenhouse gases. Which car would emit the least amount of greenhouse gases if most of the driving were done on the highway

A JB KC LD M



Which of these is supported by the information above?

A Pets should be kept away from public parks.

B Smokers should get frequent medical checkups.

C Pet immunizations should be kept up to date.

D Smoking in enclosed places should be discouraged.

Protein and dietary fiber are beneficial to health. According to the information in the table, which flour is the most nutritious?

F Whole wheat

G White wheat

H Oat

J RiceBio/IPC 3B – Draw inferences based on data related to promotional materials for products and services.

taks objective i: nature of science. what is science? scientists use observations (process of...

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