what is biology? science: a way of using organized evidence to learn about the natural world. ...

What is Biology?

Science: A way of using organized evidence to learn about the natural world.

Biology: The branch of science that deals with living things.

So….what are living things?

Living things… Are made up of cells. Reproduce.

Sexually (humans) Asexually (bacteria)

Are based on a genetic code. Grow.

So….what are living things?

Living things… Obtain and use nutrients and energy.

Photosynthesis & Cellular Respiration Respond to their environment. Maintain a stable internal environment.

Homeostasis Change over time.

Evolution!!!

What is the Scientific Method?

1) Question 2) Hypothesis

It must be TESTABLE!!!


3) Experiment Procedure (step-by-step) Controls

What stays the same. Independent Variables

What you change….ONE THING ONLY!!! Dependent Variables

What happens based on your experimental design….the results.


4) Observations Qualitative….a description.

“The bread is cold.” Quantitative….a measurement.

“The bread is 12.4 degrees Celsius.”

5) Results 6) Conclusion (based on facts) vs.

Inference (based on opinions and unobserved information)

What are the major “levels of organization” of living things?

1) Atoms…not living. Hydrogen, Helium, Oxygen

2) Molecules…not living. Water, Ammonia, Carbon Dioxide

3) Cells…smallest unit of life. Brain cell, bacteria


4) Groups of cells Tissue, organ, organ system.

5) Organism Human, Bison, Sunflower

6) Population …group of ONE organism Herd of buffalo, field of sunflowers


7) Community…populations of different organisms living together Herd of bison AND a field of sunflowers.

8) Ecosystem…community (living things) AND non-living surroundings Bison herd, sunflower field, soil, air, water.

9) Biosphere…the Earth!

Section 3.1

Review “Levels of Organization” Individual Organism Population Community Ecosystem Biome Biosphere

How does energy flow?

All energy originates from SUNLIGHT or CHEMICAL COMPOUNDS.

Autotrophs: use energy from sunlight or chemicals to produce food. Also called PRODUCERS


Photosynthesis: the chemical process that uses energy from sunlight to convert H2O and CO2 to sugar and O2 Plants, algae

Chemosynthesis: the process that uses energy from chemicals to create carbohydrates….without light! Bacteria that live in ocean floor vents


Heterotrophs: organisms that rely on other organisms for their energy Also called CONSUMERS

Herbivores– plant-eaters Carnivores– meat-eaters Omnivores– eat plants AND meat Detrivores– feed on dead plant/animal

matter Decomposers– break down organic matter


Food chain: displays the one-way energy flow from sun (or chemicals) to autotrophs to heterotrophs

Sun producer 1st-level consumer 2nd-level consumer 3rd-level consumer


Food web: More realistic way of representing energy flow in nature…shows complex feeding relationships

What are trophic levels?

1st trophic level: PRODUCERS 2nd trophic level: Primary (1st-level)

consumers 3rd trophic level: Secondary (2nd-level)

consumers And so on….

What are energy pyramids?

Only PART of the total energy from one trophic level is passed on to the next trophic level within a food web.

(approximately 10% is passed on within each transfer)

Corn—75 ‘units’ of energy Cow—7.5 ‘units’ of energy Human—0.75 ‘units’ of energy

Where does all of the “lost” energy go?

The “lost” energy (90% of the total at each trophic level) is used in two ways:

1) Used as energy for life processes Growing, Reproducing, Moving, etc.

2) Lost as heat

What is a biomass pyramid?

Biomass: the total amount of living tissue within a given trophic level

This pyramid also usually is reduced by a factor of ~ten at each trophic level.

500,000 g of corn (plant tissue) 50,000 g of cows (1st-level consumer

tissue) 5,000 g of human tissue

How are energy pyramids related to biomass pyramids?

***Because each trophic level harvests only about 1/10th of the energy from the level below, it can support only about 1/10th the amount of living tissue.***

How is the movement of matter different from the movement of energy within an ecosystem?

Energy flows in ONE DIRECTION!!

Matter is RECYCLED!!

How is water cycled?

Evaporation: Liquid to gas

Condensation: Gas to liquid

Precipitation: Liquid in atmosphere to liquid on ground

How is water cycled?

Runoff: Liquid remains on surface

Seepage: Water soaks into ground

Transpiration: Liquid IN PLANTS to gas IN ATMOSPHERE (evaporation through leaves)

How is carbon cycled?

Refer to p. 54-55 in your textbook.

Photosynthesis: takes carbon out of atmosphere

Respiration: releases carbon into atmosphere

Human activities: release (excess) carbon into atmosphere

What shapes an ecosystem?

Biotic factors: biological influences on an organism Predators, prey, population overcrowding

Abiotic factors: physical (non-living) influences on an organism Temperature, soil, precipitation, sunlight

What shapes an ecosystem?

Together, BIOTIC and ABIOTIC factors determine the survival and growth of organisms within an ecosystem.

What is a habitat? A niche?

Habitat: The area where an organism lives.

Niche: The role of an organism within a given ecosystem.

What is a niche?

The niche of a bullfrog:Eats insects, minnowsIs eaten by snakes, raccoons,

birdsLives In or near lakes or streamsAdapts by burrowing in pond mud

to hibernateReproduces by laying eggs in

water during warm months

What is a niche?

NO TWO SPECIES CAN OCCUPY THE SAME NICHE AT THE SAME TIME IN THE SAME ECOSYSTEM!!!

This is the Competitive Exclusion Principle!

What are the 3 major interactions within an ecosystem?

1) CompetitionTwo organisms fighting for

use of a single resource at the same place at the same time…one of them will lose and not survive.


2) Predation One organism kills and feeds on

another organism.


3) Symbiosis Mutualism

Both species benefit (Bird & Rhino) Commensalism

One benefits, one doesn’t care (Remora & Shark)

ParasitismOne benefits, one is harmed

(Fleas/Ticks/Worms & Dog)

What is succession?

Succession: the predictable series of changes experienced by an ecosystem over time.

What is primary succession?

Primary succession: Succession that begins with BARE ROCK.

Pioneer species (usually lichens) small grasses shrubs trees

What is secondary succession?

Secondary succession: Succession that begins with SOIL…usually after a disturbance (farming, forest fire, etc.)

What are major characteristics of populations?

1) Geographic distribution Where does the population live?

2) Population density How crowded is the population?

3) Growth rate How fast does the population grow?

4) Age structure How old (or young) is the entire population?

What factors affect growth rate? Three factors affect growth rate:

1) Birth rate 2) Death rate 3) Emigration/Immigration

Emigration: individuals leaving the populated area

Immigration: individuals entering the area

HOW do populations grow?

There are 2 general patterns in which populations of organisms can grow.

1) Exponential Growth 2) Logistic Growth

What is exponential growth?

Exponential growth: (J-curve) Individuals within a population grow at a constant rate over time.

NEED: Limitless food Limitless water Limitless space No predators No disease

What is logistic growth?

Logistic growth: (S-curve) Occurs when a population’s growth slows or stops after a period of exponential growth.

Growth slows or

stops when food,

shelter, etc. become

less available!


For a given population, growth slows or stops near a certain number. This number varies within every environment, based on the amount of resources available within that environment.

This number of individuals that a given environment can support is called the CARRYING CAPACITY!!


What affects carrying capacity? BIOTIC and ABIOTIC factors!!! Temperature Precipitation Shelter Food Disease

What limits populations during logistic growth?

Limiting factors: cause the growth of a population to slow or stop 1) Competition 2) Predation 3) Parasitism and disease 4) Drought and other climate factors 5) Human disturbance

What are density-dependent limiting factors?

Density-dependent factor: a limiting factor that depends on POPULATION DENSITY!

Competition…for food, water, space, sunlight

Predation…deer / moose-wolf example Disease Anything else related to overcrowding!!

What are density-independent limiting factors?

Density-independent factor: a limiting factor that affects all populations in the same ways, regardless of the density of the population.

Weather (floods, storms, etc.) Natural disasters Human activities (roads, logging, dams,

etc.)

What are age structure diagrams?

Age structure diagrams: display the numbers of people within different age groups in a population. Good predictor of future population growth!

P. 62-63 #1-8, 13-15, 17-22

Read p. 132-134

p. 136-137 #5, 10-12

What is demography?

Demography: the study of human populations

What is happening to the human population?

From 10,000 B.C. until 1500 A.D., growth was very slow.

From 1500-2006 (and especially 1800-2006), growth has been exponential!! WHY?

Agriculture Industry/Technology Health care


As societies become more modern, increase their level of education, and raise their standard of living, birth rates fall AND death rates fall.

When the birth rate is LOWER than the death rate, population growth stops, and that population has undergone the demographic transition.


Areas such as JAPAN, UNITED STATES, and EUROPE have completed the demographic transition.

Many areas within AFRICA, ASIA, and SOUTH AMERICA have NOT…their populations are still growing rapidly!!

How do humans affect the biosphere?

Humans affect the biosphere by…

Hunting and gathering Agriculture Industry Urban Development

What developments have led to human population growth?

Agriculture: provided sustainable food resources for large amounts of people

Green Revolution: Use of chemical fertilizers, pesticides, and modern techniques to greatly increase the world’s food supply.

Industry/Urban Development: More technology = easier life = longer life span and more babies!!

What are natural resources?

Renewable resources: regenerate (alive) OR replenished by matter cycles Wood Water Nitrogen

Nonrenewable resources: cannot be replenished naturally Oil Gas Coal


Nonrenewable resources are running out as more and more people use them!!

Renewable resources can also be severely damaged in both quality and quantity as more and more people use them…water pollution, deforestation, etc.


How do we use resources responsibly?

Sustainable development: Using natural resources responsibly without depleting them or reducing their quality


Types of resources include… Land resources– coal, oil, soil Forest resources– trees, animals Fishery resources– fish Air resources– O2 (+ ozone/greenhouse layer) Freshwater resources– drinking water, animals

ALL of these can be negatively affected by human development and activity!!!

What is biodiversity?

Biodiversity: biological diversity (diversity…differences)

Species diversity Ecosystem diversity Genetic diversity

The MORE biodiversity, the BETTER!!

What threatens biodiversity?

The following factors threaten biodiversity:

Habitat reduction or fragmentation Overhunting/fishing Pollution Invasive species…(kudzu, zebra mussels, etc.) Ozone depletion = more UV rays hitting Earth (from

CFCs) Global warming

What is the greenhouse effect?

Greenhouse effect: the situation in which solar heat is retained by a layer of “greenhouse gases” to warm the Earth and maintain a constant temperature.

Greenhouse gases include: Carbon dioxide Methane Water vapor

Is the greenhouse effect bad?

NO!!! Under normal circumstances, the greenhouse effect is not bad.

BUT, because air pollution is making the “blanket” of greenhouse gases thicker, MORE heat is being trapped inside the Earth, leading to GLOBAL WARMING.

What else affects climate?

1) Latitude The angle of sunlight is more DIRECT at

the equator, and therefore this zone is warmer.

Tropical Zone: Direct sunlight...hot Temperate Zone: Moderate sunlight…

seasonal temperature changes Polar Zone: Very angled, indirect sunlight…

cold

What else affects climate?

2) Winds 3) Ocean currents

Both rely on the following principle: Hot air/water RISES Cold air/water SINKS

What are the 4 states of matter?

Solid: arranged in a DEFINITE PATTERN, with a definite shape and a definite volume that never changes.

Liquid: have a definite volume that never changes, but does NOT have a definite shape

What are the 4 states of matter?

Gas: particles move very fast and can be very spread out…have no definite shape AND no definite volume (they can expand and shrink)

Plasma: gases heated to above 5000o C.

Electrons are knocked away from the atoms because they collide very violently.

What is the basis of chemistry? The atom: “unable to be cut”; the basic

unit of matter Proton (+)

Within nucleus Neutron (O)

Within nucleus Approximately the same mass of a proton.

Electron (-) Orbits around nucleus 1/1840 the mass of a proton!!!

What is the Periodic Table?

Atomic Number # of protons in an atom

Mass Number # of protons + # of neutrons in an atom

The Periodic Table is organized numerically by atomic number.

What are atoms? Atoms (elements) are usually NEUTRAL…they

have the same number of protons as electrons. One atom makes up a specific ELEMENT, which cannot be broken down into smaller parts.

Isotopes have different numbers of neutrons than regular elements. Therefore, they have a different mass number!!!

Ions have different numbers of electrons than regular elements.

What is a compound?

A chemical compound is a substance formed by the chemical combination of two or more elements. NaCl H2O

The MOLECULE is the smallest unit of compounds.

What are the two types of chemical bonds?

Ionic Bonds Electrons are TRANSFERRED between

atoms. “+ vs. –” attraction

Covalent Bonds Electrons are SHARED between atoms.

What happens when compound combine?

Mixture: Salt and Pepper Can be PHYSICALLY separated!!!

Solution: Saltwater (dissolved particles) Solute—salt Solvent—water

Suspension: Blood (undissolved particles)

What are acids, bases, and pHs?

In a solution, H20 dissolves to form H+ and OH- ions.

pH measures the ratio of H+ to OH- ions in a solution.


Acid pH 0.1 to 6.9 More H+ ions than OH- ions

Base pH 7.1 to 14 More OH- ions than H+ ions


Neutral Substance pH 7 H+ and OH- concentration is equal

Buffer Maintains homeostasis by controlling

sudden pH changes.

What is carbon?

All living things on Earth are primarily composed of CARBON (and water).

WHY? It is very easy for the carbon atom to form

bonds with other carbon atoms and with many other different elements.

Therefore, carbon is an ‘ingredient’ in MANY natural molecules….also called ORGANIC MOLECULES.

What is a macromolecule?

Macromolecule: “giant molecule” Most macromolecules are based upon

carbon and are called polymers.

Monomers (small units) join together to make polymers (large units—chains).

What are the 4 major natural polymers?

Carbohydrates Lipids Nucleic Acids Proteins

What are carbohydrates?

Carbohydrates: composed of C, H, O.

Used as an energy source for living things.

3 categories: Monosaccharides—glucose, fructose Disaccharides-- sucrose Polysaccharides– glycogen, starch,

cellulose

What are lipids?

Lipids: composed of mostly C, H. Not soluble in water. Used as energy storage for living things. Part of the cell membrane for animal cells. Made up of FATTY ACIDS and GLYCEROL

Three categories: Fats Oils Waxes

What are nucleic acids?

Nucleic acids: composed of H, N, O, C, P.

Molecules are called nucleotides. Used as storage and transfer device for

genetic information.

Two categories: DNA (deoxyribonucleic acid) RNA (ribonucleic acid)

What are proteins?

Proteins: composed of N, C, H, O. Made up of chains of AMINO ACIDS.

These chains are joined by PEPTIDE BONDS.

Used for: regulation of cell processes formation of bones/muscles transportation of substances fighting disease cell structure components enzymes

How do chemical reactions work?

Chemical reaction: process that changes one set of chemicals to another set of chemicals by breaking bonds and forming new ones.

You START with reactants. You FINISH with products.

What are some examples of chemical reactions?

2H2 + O2 2H2O

6H2O + 6CO2 C6H12O6 + 6O2

CH3CO2H + NaHCO3 CO2 + NaCO3 + H2O

What is activation energy?

Activation energy: the energy needed to start a chemical reaction

Catalysts: speed up chemical reactions by reducing the amount of activation energy needed to start them

What are enzymes?

Enzymes: proteins that are natural catalysts!!!

Enzymes provide a site for a chemical reaction to take place.

How does an enzyme-influenced chemical reaction occur?

1-- Reactants (called SUBSTRATES) bind to the ACTIVE SITE of an enzyme.

2-- (Sped-up) chemical reaction takes place.

3-- Products are released from the enzyme.

How does an enzyme-influenced chemical reaction occur?

Substrate = Key

Enzyme = Lock

Active Site = Keyhole within the lock

(7.1) How were cells discovered?

Robert Hooke (1665): First microscope…looked at cork and discovered tiny, empty chambers—PLANT CELLS!!

Anton van Leeuwenhoek (1665-ish): First used microscope to observe LIVING cells in pond water.

What is the cell theory?

By 1839, scientists concluded that all plants and animals were made of cells.

This discovery (and related discoveries) led to the formation of the cell theory: 1) All living things are made of cells. 2) Cells are the basic units of structure and

function in living things. 3) New cells are produced from existing

cells.

How are cells investigated today?

Fluorescent labels of cell components. 3-D imaging. Electron microscopes (3-D and 1000X

more magnified than light microscopes).

What is the difference between prokaryotes and eukaryotes?

Eukaryotes: cells that contain a nucleus Larger and more complex Genetic material (DNA) is inside nucleus Contain organelles

Plants, animals, fungi, protists

What is the difference between prokaryotes and eukaryotes?

Prokaryotes: cells that do not contain a nucleus Smaller and simpler Have genetic material (DNA), but not

inside a nucleus Usually no organelles, except ribosomes

Bacteria

(7.2) What are organelles?

Organelles: “tiny organs”…small structures within cells (eukaryotes) that perform specific functions

Reside in the cytoplasm Cytoplasm: portion inside the cell that is

OUTSIDE the nucleus

Organelle Overview

1) Nucleus: Contains DNA to provide instructions for cell functions.

2) Ribosomes: Small spheres on which proteins are assembled.

3) Endoplasmic Reticulum: Ribosomes reside on the rough ER; lipids are made on smooth ER

Organelle Overview

4) Golgi apparatus: Modifies, sorts, and packages proteins and other cell products for storage or export.

5) Lysosomes: Filled with enzymes to break down food (or waste) products.

6) Vacuoles: Storage tanks for food/water.

Organelle Overview

7a) Mitochondria (animal/plant cells): convert food into energy. Contain their own DNA.

7b) Chloroplasts (plant cells): convert sunlight into food Contain their own DNA.

Organelle Overview

8) Cytoskeleton: help provide shape and structure to the cell. Microfilaments: provide tough, flexible

support Microtubules: assist in cell division AND

cell transportation through CILIA and FLAGELLA

What is the endosymbiotic theory?

Endosymbiotic theory: Since mitochondria and chloroplasts have their own DNA, they were likely prokaryotes (separate cells) that formed a symbiotic relationship with larger eukaryotes and resided inside eukaryotic cells. Later, these prokaryotic cells just evolved into organelles (mitochondria and chloroplasts).

(7.3) What is the function of the cell membrane?

Cell membrane: regulates what enters and leaves the cell (and how much of it) Provides protection Provides support Lipid Bilayer

Contains protein channels to allow for passing of materials

What is a cell wall?

Cell wall: provides support and protection for the cell Only in plants, fungi, and some

prokaryotes Very rigid Carbohydrate and protein composition Very porous, so cannot regulate anything

that passes through.

(7.4) How do cells make organisms?

Unicellular organisms: a single cell that IS an organism!

Multicellular organisms: organisms made up of many SPECIALIZED cells Blood cells (oxygen transport) Pancreatic cells (enzymes for food

digestion) Muscle cells (movement)

How do cells make organisms?

Plants have many different types of specialized cells too… Guard cells (regulate gas exchange) Vascular cells (water/nutrient transport)

What are the major levels of organization in living things?

1) Cell 2) Tissue 3) Organ 4) Organ System

What are the major levels of organization in living things?

Tissue: groups of similar cells

Organ: groups of similar tissues

Organ system: groups of similar organs

***Specialized cells WORK TOGETHER to allow organ systems to work and INTERACT to allow all bodily processes to function!!!

(7.3) What is the function of the cell membrane?

Cell membrane: regulates what enters and leaves the cell (and how much of it) Provides protection Provides support Lipid Bilayer

Contains protein channels to allow for passing of materials

What is a cell wall?

Cell wall: provides support and protection for the cell Only in plants, fungi, and some

prokaryotes Very rigid Carbohydrate and protein composition Very porous, so cannot regulate anything

that passes through.

What is diffusion?

Every living cell NEEDS to exist in a very exact liquid environment, or it will DIE.

Concentration: mass of particles in a volume of liquid

12 g salt in 6 L water 2 g/L

What is diffusion?

Diffusion: movement of particles from an area of higher concentration to an area of lower concentration Diffusion stops only when a cell system

has reached equilibrium.

What is diffusion?

Diffusion does NOT require any energy from the cell, therefore is called “passive transport”.

What is osmosis?

Osmosis: the diffusion of WATER through a selectively permeable membrane.

Water wants to DISSOLVE an area of high particle concentration.

What is osmosis?

Isotonic: Both portions of the solution are of the same concentration.

If two portions of a solution have UNEQUAL concentrations, then… Hypertonic: The portion of the solution

with the higher concentration Hypotonic: The portion of the solution with

the lower concentration.

What is osmosis?

If a cell is in a hypertonic solution, then water moves OUT of the cell in order to dissolve the outside solution, and the cell SHRINKS.

If a cell is in a hypotonic solution, then water moves IN to the cell in order to dissolve the solution within the cell, and the cell EXPANDS.

What is facilitated diffusion?

Facilitated diffusion: Movement of particles from higher concentration to lower concentration….BUT:

For particles that are too large to pass through the lipid bilayer….particles instead pass through protein channels

Since this is still a type of diffusion, it requires NO energy (passive transport).

What is active transport?

Active transport: movement of particles from an area of lower concentration to an area of higher concentration Uses protein channels…”pumps” Requires ENERGY!!

What is endocytosis? Endocytosis: the process of taking

materials (usually food) into a cell through pockets within the cell membrane. Phagocytosis: “cell eating”…large food

molecules Pinocytosis: “cell drinking”…liquids

Exocytosis: the release of material (usually waste) from a cell

What is exocytosis?

Exocytosis: the release of material (usually waste) from a cell

(8.1) What is photosynthesis?

Autotrophs: organisms that make their own food

Heterotrophs: can’t make their own food, so they EAT it

ATP: (adenosine triphosphate) chemical compound used to release ENERGY

What is photosynthesis? ATP: (adenosine triphosphate) chemical

compound used to release ENERGY ADP: (adenosine diphosphate)

“uncharged battery” compound within organisms used to store energy When an organism wants to STORE

energy, it adds a third phosphate molecule to ADP to produce ATP, which acts as a “charged battery”

When an organism wants to RELEASE energy, it breaks the chemical bond between the 2nd and 3rd phosphate molecule.

What is photosynthesis?

Energy from ATP can be used for… Active transport (across cell membranes) Muscle contraction (movement) Protein synthesis (within ribosomes) Light production (in fireflies)


Problems with ATP… ATP cannot store energy for a long time (it

loses its “charge” easily

SO, energy is stored within ADP and other large ‘storage’ molecules such as GLUCOSE, and the energy from glucose is used to add a ‘P’ to ADP to produce ATP only when needed.

(8.2) How was photosynthesis discovered?

Photosynthesis: plants use energy from sunlight to convert water (H2O) and carbon dioxide (CO2) into carbohydrates (glucose…C6H12O6) and a waste product—oxygen (O2).

H2O + CO2 + sunlight C6H12O6 + O2

How was photosynthesis discovered?

Where does a tree’s increase in mass come from as it grows over the years???

THREE EXPERIMENTS… 1) Van Helmont (1600s): most of a plant’s

mass as it grows comes from WATER

2) Priestley (1700s): plants release OXYGEN when they grow (candle expt.)

How was photosynthesis discovered?

3) Ingenhousz (late 1700s): in order to produce oxygen, a plant needs LIGHT

(He just repeated Priestley’s expt., but ran one test in the dark and one in sunlight)

6CO2 + 6H2O ----light---> C6H12O6 + 6O2

What else do plants need to undergo photosynthesis?

Plants need carbon dioxide and water, but they ALSO need a molecule called CHLOROPHYLL (housed in chloroplasts) to capture energy within sunlight

Sunlight is not “white”…it’s actually a mix of violet, blue, green, yellow, orange, & red


Chlorophyll ABSORBS energy from sunlight. Two types…

Chlorophyll ‘b’ absorbs violet and blue light Chlorophyll ‘a’ absorbs yellow, orange, & red

light

(the only color of sunlight that is NOT absorbed is green….green is therefore REFLECTED, and that is why most plants appear to be green!!!)


The energy that is absorbed from the sunlight is used to drive the chemical reaction that breaks down CO2 and H2O to make the sugars and oxygen within photosynthesis!

(8.3) What makes up a chloroplast?

(Photosynthesis takes place inside chloroplasts) Thylakoids: sac-like membranes arranged

in stacks called GRANA Light-dependent reactions take place here.

Stroma: region outside the thylakoid membranes

Light-independent (dark) reactions take place here.

Also called Calvin Cycle


Photosynthesis consists of TWO major chemical reactions… Light-dependent reactions

Need sunlight Use H2O to produce ATP, NADPH, and O2

Calvin Cycle Use CO2 and ATP/NADPH to produce sugars (and send ADP/NADP+ back to light-

dependent reactions)

What happens within the Calvin Cycle?

During the Calvin Cycle, ATP and NADPH that are created during the light-dependent reactions are used to fuel the production of glucose.

What happens within the Calvin Cycle?

Overall, 6 CO2 molecules are used to make a single 6-carbon sugar (glucose)!!!

What factors affect photosynthesis?

Factors that affect photosynthesis include…

1) Drought…plants need H2O in light-dependent reactions!!

2) Temperature…photosynthesis works best between 0-35o Celsius.

3) Light Intensity…shade/sun factors into the speed of photosynthesis.

What is cellular respiration?

Cellular respiration: process that releases energy by breaking down glucose (and other food molecules) in the presence of oxygen

6O2 + C6H12O6 6CO2 + 6H2O + energy

What is cellular respiration?

Cellular respiration takes place in the MITOCHONDRIA!!!

3 major stages of cellular respiration…

1) Glycolysis

2) Krebs Cycle (a.k.a. Citric Acid Cycle)

3) Electron Transport Chain (ETC)

ALL THREE STAGES PRODUCE ATP!!!

What is glycolysis?

Glycolysis: first step in releasing the energy of glucose 1 molecule of glucose is broken down into

two molecules of pyruvic acid…simply broken in half

Uses 2 ATP molecules to break down glucose, but 4 ATP’s are produced!

A “net gain” of 2 ATP’s!!

What is glycolysis?

AFTER glycolysis, two processes may occur…

If oxygen IS present, the Krebs Cycle occurs.

If oxygen IS NOT present, fermentation occurs.

What is fermentation?

Fermentation: the release of energy from food molecules by producing ATP in the absence of oxygen (anaerobic environment) Very inefficient when compared to aerobic

processes

1) Alcoholic fermentation (in yeast) 2) Lactic acid fermentation (in humans)

What is fermentation?

Lactic acid fermentation: occurs within muscle cells of animals when insufficient oxygen is available Lactic acid causes “burning muscles” after

running or working out!!!

(9.2) What happens after glycolysis (when there is oxygen)?

Remember…after glycolysis, if there is no oxygen, then fermentation occurs.

If there IS oxygen, then the Krebs Cycle occurs.

At the end of glycolysis, 90% of the energy within glucose is still available…we need to extract it!!!

What happens after glycolysis (when there is oxygen)?

Aerobic: with oxygen Anaerobic: without oxygen If there IS oxygen, then the Krebs Cycle

occurs.

Krebs Cycle (citric acid cycle)…pyruvic acid is broken down into carbon dioxide, and energy is released.

What is the ETC?

ETC: uses “batteries” produced during Krebs Cycle to produce more ATP.

How much ATP is produced during cellular respiration?

For each glucose molecule…

Glycolysis: 2 ATPs are made

Krebs Cycle/ETC: 34 additional ATPs are made

36 TOTAL ATPs (with oxygen) Only 2 total ATPs (without oxygen)

What makes up DNA?

Ingredients of DNA include…

Nucleotides: sugar (deoxyribose), phosphate group, nitrogenous base.

Nucleotides, chained together, form a DNA molecule.

There are 4 n-bases in DNA Adenine, Guanine, Cytosine, Thymine (A, G,

C, T)

What are Chargaff’s rules?

G always matches with C A always matches with T

What is a double helix?

Watson and Crick: discovered structure of DNA molecule

Double helix:

“twisted ladder”

(12.2) How does DNA replicate?

Prokaryotes: usually have ONE circular DNA molecule

Eukaryotes: usually have MULTIPLE elongated DNA molecules

How does DNA replicate?

Chromosomes are SO long, they have to be tightly wrapped in order to fit into a cell’s nucleus!

There is over 1 meter of DNA in each nucleus of each human cell!!!!!!!!!!!!!!


DNA “coils” in the following way…

1) DNA wraps around histones (protein spheres) to form nucleosomes (bead-like DNA/histone combo)

2) Nucleosomes coil/wrap around each other very tightly to form a chromosome.


DNA replication… 1) DNA splits at multiple locations along the

strand at replication forks. DNA polymerase enzyme ‘unzips’ double strand. (Hydrogen bonds connecting strands are broken.)

2) Two strands of “double helix” completely separate.

3) New n-bases attach to each original strand (A-T and C-G) to form two new “complementary strands”.

4) Both new double-stranded molecules “twist” into a double helix.


Before replication: 1 double helix

After replication: 2 double helices Each with one original strand and one

complementary strand! (Semi-conservative replication.)

(12.3) How does RNA differ from DNA?

Genes are coded in DNA…..but, you must DECODE the DNA!!!

RNA is a molecule that assists in the gene decoding process.

(DNA contains the instructions to make proteins, but RNA actually participates in the protein-making process.)

How does RNA differ from DNA?

RNA is different from DNA in these ways:

1) RNA’s sugar is ribose, not deoxyribose 2) RNA is single-stranded, not double-

stranded 3) RNA contains Uracil instead of Thymine

A, C, G, U instead of A, C, G, T

What is RNA?

Three types of RNA… 1) Messenger RNA (mRNA): messengers from

DNA to the rest of the cell (specifically ribosomes)

2) Transfer RNA (tRNA): assists in the assembly of proteins during translation

3) Ribosomal RNA (rRNA): ingredient of ribosomes

What is transcription?

Transcription: the process of copying nucleotide sequences from DNA into a complementary sequence in RNA

Process… 1) RNA polymerase (enzyme) “unzips”

double-stranded DNA in nucleus. Bind at PROMOTERS (“start signal” areas

of DNA)

What is transcription?

2) One strand of DNA (template strand) is used to assemble a complementary strand of RNA. T A, A U, G C, C G

3) RNA is sent from the nucleus to the ribosome for TRANSLATION

How is RNA edited?

Introns: DNA sequences that are “useless” in protein production

Exons: DNA sequences that code for proteins….”useful”

To finish transcription, introns are cut out and the remaining exons are “glued” back together so 100% of the new RNA molecule is “useful”.

How does one read the genetic code?

Codon: three nucleotides that specify a single amino acid Amino acid = ingredients of proteins

RNA = UCGCACGGU Three codons are ‘UCG’ ‘CAC’ ‘GGU’ UCG Serine (amino acid) CAC Histidine GGU Glycine

What is translation?

Translation: process of decoding an mRNA message into an amino acid chain to produce a PROTEIN. (see Fig. 11.9 on p. 294)

Process… 1) mRNA attaches to a ribosome. 2) Each codon on mRNA is “read” and the

proper amino acid is attached to a chain by tRNA.

3) Protein chain is complete when a “STOP” codon is read.

(12.4) What are mutations?

Mutations: changes in genetic material Caused by mistakes in copying DNA

Inserting an incorrect n-base Skipping an n-base

What are mutations?

Gene mutations: occur in a single gene Chromosomal mutations: occur and

produce changes in a whole chromosome

What are mutations?

Point mutations: change one or a few n-bases; occur at a single point in the DNA sequence

What are mutations?

Frameshift mutations: addition or deletion of an n-base that shifts the reading frame of the gene More dangerous than point mutations b/c

they can alter the ENTIRE amino acid sequence instead of just one amino acid…ALL codons can be affected!!!

What are mutations?

Chromosomal mutations: changes in the number or structure of entire chromosomes May delete entire genes, change location

of genes, or make extra copies of genes

Why are mutations important?

Most mutations are NEUTRAL…they have no effect on protein production and gene function.

Harmful mutations cause genetic disease, cancers, etc. (Ch. 14)

Beneficial mutations increase genetic variability in organisms and allow species to evolve more quickly by adapting to the environment.

(12.5) How and when are genes expressed?

Not all genes in a cell are expressed all the time.

GENE REGULATION controls when genes should be turned “on” for transcription/translation and when they should be turned “off”

How are genes regulated?

Genes usually contain specific regions for regulation Promoter (RNA polymerase binds to start

transcription) Operator (Repressor can bind to this

region to turn gene “off”; if repressor is NOT bound to operator, gene is “on)

Coding sequence (the actual n-base code for amino acid/protein production)

Stop sequence


Gene regulation is ALWAYS important, but is extremely important during embryonic growth. Certain genes need to be turned on/off at

specific times in order for an organism to grow and differentiate correctly.

DIFFERENTIATION: process that occurs that causes cells to become specialized in structure and function…stem cells turn into nerve cells, muscle cells, etc.


HOX genes: a series of genes that controls growth/differentiation of an embryo

Mutations in HOX genes lead to severe abnormalites

A certain HOX gene mutation in fruit fly embryos led to the replacement of antennae with legs!!!

(10.1) How big can a cell grow? The larger a cell is, the more demands there

are on its DNA Since DNA does not grow with the cell, there is

only so much to go around!!

The larger a cell is, the harder it is to transport sufficient nutrients and wastes across its cell membrane.

THEREFORE, cells must DIVIDE to remain SMALL in size.

What is surface area to volume ratio?

Sides of a cubic cell: 1cm Surface area = 1cm x 1cm x 6 = 6cm2

Volume = 1cm x 1cm x 1cm = 1cm3

6 to 1 ratio….a lot of area for transport!

Sides of a cubic cell: 3cm Surface area = 3cm x 3cm x 6 = 54cm2

Volume = 3cm x 3cm x 3cm = 27cm3

2 to 1 ratio….NOT a lot of area for transport!

What is the cell cycle?

Interphase: period of cell growth and copying (DNA replication)

Mitosis: period of cell division

At the end of the cycle, one “mother” cell will have split into two identical “daughter” cells!!!


Steps of the cell cycle…

1) Interphase (G1, S, G2): period of cell growth chromosomes (which hold DNA) are

replicated “sister” chromatids: two copies chromosomes Centromeres: area where “sister” chromatids

are attached


2) Cell division: mitosis AND cytokinesis


Steps of mitosis (cell division)…

1) Prophase Chromosomes thicken and become visible Centrioles separate to two opposite sides

of the nucleus Spindle fibers form at centrioles Nucleus dissolves

Why do cells need to divide?

Cells need to divide, because if they get too big… The nucleus cannot control the entire large

cell. The cell membrane cannot bring in enough

materials to keep the entire large cell alive. SO…CELLS NEED TO REMAIN SMALL

IN ORDER TO REMAIN MANAGEABLE!!


Interphase: period of cell growth and copying (DNA replication)

Mitosis: period of cell division

At the end of the cycle, one “mother” cell will have split into two identical “daughter” cells!!!

What is the cell cycle? 2) Metaphase

Chromosomes line up in the middle of the cell

Centromere of each chromosome is attached to spindle fibers

The centromere is at the middle of the ‘X’ that connects each doubled chromosome.

Each of the 2 copies of the doubled chromosome is called a “sister chromatid.”


3) Anaphase Centromeres (that join “sister” chromatids)

split “sister” chromatids separate and move to

opposite sides of the cell (pulled by spindle fibers)

Spindle fiber = fishing line Centriole = fishing reel


4) Telophase Chromosomes tangle at opposite ends of

cell Spindle fibers dissolve Nuclear membrane re-forms


5) Cytokinesis Cytoplasm divides to create two separate

“daughter” cells with individual nucleus/organelles

Animal cells: pinching Plant cells: cell plate forms (rigid)

(11.4) What is meiosis?

Meiosis: process of reduction division in which the number of chromosomes is cut in half.

What is meiosis?

Humans have 46 chromosomes, 23 from the father and 23 from the mother. These chromosomes are numbered #1-#23 and are arranged in pairs.

Each pair are called HOMOLOGOUS CHROMOSOMES.

They code for the same information, but are just different versions….paternal and maternal!!!

What is meiosis?

Human BODY cells always have 46 chromosomes (23 pairs of homologous chromosomes), and are therefore called DIPLOID cells. Diploid = 2 copies or sets

What is meiosis?

But, human SEX cells (gametes) only have ONE pair, or set, of chromosomes, and are called HAPLOID cells. Haploid = 1 pair or set

MEIOSIS: Haploid sex cells are produced from diploid cells!

What is meiosis? Phases of meiosis… 1) Interphase: growth, DNA replication

2) Meiosis I: VERY similar to mitosis A) Prophase I: each chromosome pairs with its homologous

chromosome…TETRAD, and CROSSING-OVER occurs, where alleles are exchanged between the homologous chromosomes.

B) Metaphase I

C) Anaphase I: spindle fibers pull homologous chromosomes towards opposite sides of cell

D) Telophase I/Cytokinesis

What is meiosis?

(At the end of Meiosis I, there are two haploid cells formed from one diploid cell.)

3) Meiosis II Prophase II, Metaphase II, Anaphase II, Telophase

II, and Cytokinesis all happen just like mitosis.

(At the end of Meiosis II, there are four haploid cells formed from two haploid cells.)

What is meiosis?

Male gametes: sperm/pollen 1 diploid cell makes 4 haploid gametes

Female gametes: eggs 1 diploid cell makes 1 LARGE haploid

gamete and 3 useless “polar bodies” This is due to uneven cell divisions during

meiosis within females!

What is genetics?

Genetics: the study of heredity Heredity– the passing of characteristics

from one generation to the next

How were genetic principles discovered?

Gregor Mendel: Austrian monk that discovered most basic genetic principles

In his experiments, Mendel cross-pollinated different pea plants on his own.


Mendel had true-breeding pea plants in his garden. True-breeding plants: if they were allowed

to self-pollinate, their offspring would be IDENTICAL to themselves

Mendel discovered several important characteristics of genetics…


1) DOMINANCE 7 traits (characteristics) were studied Parents with different variations of each trait

(P) were crossed to form hybrid offspring (F1)

Trait: Seed Shape P (round) x P (wrinkled) F1 was round ROUND was dominant over WRINKLED


Conclusion #1: Each trait was passed from one generation to the next (through chemical factors called GENES).

Conclusion #2: There are usually TWO forms of each gene, and each of these forms is called an ALLELE.

Conclusion #3: Some alleles are DOMINANT and some are RECESSIVE.


2) SEGREGATION What happened to the recessive allele…

did it disappear? NO!!!

Example… Cross P (tall) with P (short) ‘tall’ is dominant, so F1 plants are all tall BUT, then cross an F1 with another F1 and

get 3 tall plants and one short plant…the recessive allele did NOT disappear!


Segregation: the two different alleles for each gene SEPARATE from each other during formation of GAMETES (sex cells).

(11.2) How can we predict the outcomes of genetic crosses?

Punnett square: a diagram that displays results from a genetic cross Assume that each genetic trait has two

alleles Dominant allele = capital letter (T) Recessive allele = lowercase letter (t)

TT: Homozygous dominant tt: Homozygous recessive Tt: Heterozygous

How can we predict the outcomes of genetic crosses?

Phenotype: physical characteristics “the plant is tall”

Genotype: genetic makeup “the plant is homozygous dominant, TT”

(11.3) What is independent assortment?

After Mendel figured out that one allele was DOMINANT over another allele, and that these two alleles SEGREGATE independently into gametes, he had another question….

Does the segregation of one pair of alleles affect the segregation of another pair of alleles?

Does the gene determining seed shape related to the gene determining seed color?

What is independent assortment?

Step 1: Crossed round yellow peas (RRYY) with wrinkled green peas (rryy)

Step 2: Proved that round (R) and yellow (Y) were dominant, since all F1 offspring were… Phenotype: Round and Yellow Genotype: RrYy

What is independent assortment?

Step 3: Cross F1 plant with F1 plant (RrYy x RrYy)

Step 4: Results (F2 generation) produced all possible combinations of offspring RRYY, RRYy, RrYY, RrYy, RRyy, rrYY, rrYy, Rryy, rryy

Seed shape alleles SEGREGATED INDEPENDENTLY from seed color alleles!!!

Principle of Independent Assortment!!!

What are some exceptions to Mendel’s discoveries?

There are exceptions to Mendel’s “genetic principles”!


Exception #1: Incomplete Dominance Heterozygous phenotype is halfway in

between the two homozygous phenotypes Red x white = pink!!!

Exception #2: Codominance Both alleles contribute to phenotype

Black x white = black and white spots!


Exception #3: Multiple Alleles Many genes have MORE than two alleles

Rabbit coat color (C, c, cch, ch) Human blood type (A, B, O)

Exception #4: Polygenic Traits Traits produced by interaction of more than

one gene Human skin color and height

(14.1) What is a karyotype?

What is a karyotype?

Karyotype: a picture of all 46 human chromosomes arranged within their homologous pairs

Sex chromosomes (pair #23): X and Y (XX = female and XY = male)

Autosomes (pairs #1-#22): the “other” 44 chromosomes in a human

What is a pedigree? Pedigree: chart showing the genetic

relationships within a family

Human Genes

Study blood group genes on p. 344/345 IA and IB

and i are the alleles (3)

Rh+ and Rh- are the alleles for

positive/negative blood type

Most genetic disorders are causes by recessive alleles p. 345 Chart

Human Genes

Cystic fibrosis (CF): caused by a recessive allele on chromosome #7

Sickle cell anemia: caused by a point mutation in a recessive allele on chromosome #11

Sex-linked genes

Sex-linked genes are on X & Y chromosomes Most alleles are found on the X chromosome,

and are called ‘X-linked’

Males are affected by X-linked disorders more often than females because they have only one X chromosome, so if it is defective, they have no “backup” X to cover for the mistakes like females do.

Colorblindness, Hemophilia, Duchenne muscular dystrophy

X-inactivation

In females, it is unhealthy to have both X-chromosomes “turned on” at the same time, so one is always inactivated

If one X is defective, it is always switched “off” In different parts of the body, a different X may be

“on” or “off” X1 may be on in the torso while X2 may be off, but

X2 may be on in the head/neck area while X1 may be off.

Cat example

How many genes are on chromosomes?

There are many genes on autosomes. Chromosomes #21/22 are the smallest

human chromosomes. Combined, they hold at least 770 genes!!

What causes chromosomal disorders?

Chromosomal disorders: result from extra (or missing) chromosomes or parts of chromosomes usually caused by nondisjunction. Nondisjunction: homologous

chromosomes fail to separate during meiosis

DOWN SYNDROME: “Trisomy-21” TURNER’S SYNDROME: X KLINEFELTER’S SYNDROME: XXY

Ch. 13 Overview

Selective breeding: humans CONTROL reproduction of organisms to allow specific traits to be passed to offspring

Dogs…a Chihuahua and a Great Dane are the SAME species, but have been bred in a VERY different manner for 1000s of years

Ch. 13 Overview

Hybridization: crossing (mating) individuals that are NOT similar in order increase the gene pool and bring together the “best of both worlds” GOOD (seedless watermelons)

Inbreeding: crossing (mating) individuals that are similar in order to preserve physical characteristics BAD

Ch. 13 Overview

Inducing mutations: cause mutations on purpose to “see what will happen”…sometimes, it is good!

Ch. 13 Overview

Genetic engineering: making changes in the DNA code of a living thing DNA extraction DNA cutting and DNA

separation Restriction enzymes: cut DNA at specific

points Gel electrophoresis: technique used to

separate DNA based on electric charge and size

Ch. 13 Overview

Recombinant DNA: DNA molecules created by taking a gene from one organism and attaching it to the DNA of a different organism….GENE THERAPY!!!

Polymerase Chain Reaction (PCR): high-speed copying process for DNA

Ch. 13 Overview

Transformation: DNA fragments (or genes) are inserted into the DNA of an existing cell (creating recombinant DNA)

Transgenic organisms: organisms that contain DNA from a different species Human insulin gene inserted into

bacteria…now this bacteria makes human insulin for medical use!!!

Ch. 13 Overview

Transgenic organisms, continued… Transgenic mice have been implanted with

human genes for research 52% of soybeans/25% of corn produced in

U.S. are transgenic

Clone: a population of genetically identical cells produced from a single existing cell

Cloned animals can now be produced

What is the Human Genome Project?

Human Genome Project: effort to analyze the entire human DNA sequence and locate all genes within all chromosomes

Gene Therapy: replacing an absent or defective gene with a gene that works Remove bone marrow, modify all cells, replace it

Ethical issues…how far should science go to alter the basis of life on Earth???????

What is evolution?

Evolution: change over time Charles Darwin: voyaged on the HMS Beagle to

collect evidence for his theory

Darwin found that all species were specifically adapted to their environments. Tortoise & Finch population of the Galapagos

Islands

SEPARATE SPECIES EVOLVED FROM ONE “PARENT” SPECIES!!!!!

What ideas preceded evolution?

Before Darwin, most people believed that living things had been created no more than 2000-3000 years ago.

BUT…old fossils were being discovered that were MILLIONS of years old.


James Hutton: proposed that Earth had to be much older than ~3000 years old

Charles Lyell: proposed that geologic features on Earth change over time…life probably changed as well!


Jean-Baptiste Lamarck: “Use/Disuse Theory”…first ‘evolution-like’ theory If an organism used/did not use a

particular feature in its lifetime, this use/disuse would be passed on to offspring

(If a man was a bodybuilder, his child would be naturally muscular.)

WRONG!!! (but it was an interesting idea)

What ideas preceded evolution? Thomas Malthus: if the human

population grew continuously, we would hit the Earth’s carrying capacity and people would die.

Darwin agreed, and thought… “WHY haven’t plants/animals grown

continuously over time? WHAT causes some to survive and others to die? HMMMM….

Darwin’s Evidence of Evolution

On the Origin of Species: Darwin’s book about evolution (1859) Topics included…

NATURAL SELECTION PHYSICAL EVIDENCE FOR EVOLUTION


Artificial selection: nature provides genetic variation and humans select desirable traits for further mating…crops/livestock were undergoing an “artificial evolution”!!!

Struggle for existence: animals survive that are faster, stronger, better camouflaged, better protected, etc. than those who are slower, weaker, etc.


Survival of the fittest: individuals with adaptations that enable fitness survive and reproduce most successfully

Also called “natural selection”

Adaptation = an inherited characteristic that increases an organism’s chances of survival

Fitness = ability of an organism to survive in its environment


OVER TIME, NATURAL SELECTION RESULTS IN CHANGES IN THE INHERITED CHARACTERISTICS (the genes) OF A POPULATION!!!

Descent with modification: each species in existence today came from other species over time…they just changed in some way(s) EVERYTHING came from a SINGLE organism

(COMMON DESCENT)


EVIDENCE: 1) Fossils: a person can “see” an

organism evolving through history by looking at fossils of different ages

2) Embryology: early embryos of many animals look almost EXACTLY the same!


3) Homologous body structures: organs or limbs differ in form or function, but contain SAME basic structures

Turtle leg, alligator leg, bird wing, human finger all have similar bone structure and likely all came from a specific ancient fish fin!

Homologous = related by evolution & genes {HUMAN ARM & DOLPHIN FIN}

Analogous = look the same, but NOT related by evolution & genes {DOLPHIN FIN & SWORDFISH FIN}

Evolution of Populations

(This chapter connects evolution with genetics….it is all about what Darwin DIDN’T know!!!)

Genetic variation: all organisms have many different allele combinations for their genes within an entire population


Gene pool: all genes and alleles that are present in a population

Relative frequency: # of times that an allele occurs in a gene pool for a single gene

EVOLUTION = ANY CHANGE IN THE RELATIVE FREQUENCY OF ALLELES IN A POPULATION


How do genes become “varied”? 1) Mutations 2) Gene shuffling….crossing over and

sperm-egg combinations!


Natural selection works differently on single-gene traits than it does on polygenic traits.

Single-gene traits: natural selection can “select for” the dominant or recessive allele, and the relative frequency may change


Polygenic traits: Directional selection

Organisms at ONE END of the curve have highest fitness

Stabilizing selection Organisms near CENTER of the curve have

highest fitness Disruptive selection

Organisms at BOTH ENDS of the curve have highest fitness


Natural selection is NOT the only mechanism of evolution…GENETIC DRIFT is another mechanism.

Genetic drift: if a CHANCE OCCURRENCE causes change in a population…has nothing to do with “survival of the fittest” Only occurs in small populations


Hardy-Weinberg Principle: allele frequencies in a population will remain constant (at “genetic equilibrium”) if 5 conditions are met…

1) Random mating 2) Large population 3) No immigration or emigration 4) No mutations 5) No natural selection IF any one of these conditions is NOT met,

then EVOLUTION will occur!!

What is speciation?

Speciation: formation of a new species

Reproductive isolation: two different species CANNOT successfully mate with each other Behavioral: different courtship rituals (BIRD

MATING DANCES OR SONGS) Geographic: separated by rivers, mountains

(GRAND CANYON SQUIRRELS) Temporal: different mating seasons (FLOWERS)

How does natural selection work in nature?

Darwin’s “process” of evolution: Founding Separation of populations Different adaptations Gene pool

changes Reproductive isolation occurs Competition REPEAT

(18.1) How are organisms classified?

Taxonomy: study of the logical organization of all living things

Binomial nomenclature: two-word name Genus name (capitalized) Species name (NOT capitalized)

Homo sapiens

How are organisms classified?

Carolus Linnaeus: Swedish scientist who classified organisms in a 8-level system Domain Kingdom Phylum Class Order Family Genus Species


Phylogeny: study of evolutionary relationships among organisms

Cladogram: diagram that shows evolutionary relationships among organisms Species sharing the same “fork” or that

reside close together on a cladogram are closely related


Similarities in DNA sequence is an excellent way to determine evolutionary relationships among organisms.


Two different classification systems… 1) Domain system

Bacteria, Archaea, Eukarya (3) 2) Kingdom system

Eubacteria, Archaebacteria, Protista, Fungi, Plantae, Animalia (6)


Dichotomous key: method of using a series of “yes” and “no” questions to classify large groups of organisms and make identifications of specific organisms

Plant Overview

Plant Overview

Stamen: male ‘parts’ Anther: tip that makes/releases pollen Filament: stalk that supports the anther

Carpel (Pistil): female ‘parts’ Stigma: sticky tip Style: stalk leading from stigma to ovary Ovary: chamber containing ovules Ovule: female egg

Plant Overview

Sepal: outermost, leafy flower parts Petal: brightly colored, inner flower parts

ATTRACT POLLINATORS!! Pollination occurs via…

Wind Animals

Plant Overview

After pollination & fertilization, a seed is formed. Then…

1) Dispersal: seeds spread by wind, water, animals

2) Dormancy: seeds “sleep” until environment is ideal for growth

FIRE CHERRY: SEEDS DO NOT GERMINATE UNTIL THERE IS A FOREST FIRE

3) Germination: early growth of plant…eruption from seed

Plant Overview

Plant Hormones:

1) Auxins: regulate stem growth 2) Cytokinins: regulate root growth 3) Gibberellins: produce huge size in

stems and fruit 4) Ethylene: stimulates fruits to ripen

Plant Overview

Plant responses:

1) Phototropism: plants grow toward light 2) Gravitropism: plants grow AGAINST

gravity

Plant Overview

Plant adaptations:

1) Salt: excess salt is released through leaves and then washed off by rain

2) Desert: large root systems, small leaves, thick, water-storing stems

3) Low nutrient levels: eat insects / parasitic plants

4) Defense: make toxic substances to kill ‘predators’

Animal Behavior (Ch. 33)

Behavior: anything an animal does in response to a stimulus INNATE BEHAVIOR LEARNED BEHAVIOR COMMUNICATION Stimulus: an environmental change that

directly influences the activity of an organism


Innate behavior: behavior patterns that are inherited by genes Behaviors lead to high fitness! 3 major types


Type 1: Fixed-action pattern Unchangeable behavior pattern Toad senses motion pinpoints motion

extends tongue to capture prey retracts tongue


Type 2: Automatic response Reflex: automatic response to stimulus

with no conscious control (jumping b/c of fire alarm)

Fight-or-Flight: mobilizes body for danger Controlled by hormones Adrenaline—increased heart rate, sweaty

palms, increased muscle sensitivity


Type 3: Instinct A) Courtship (mating dance) B) Territoriality (protection of breeding

ground, feeding ground, and sexual partners)

Wolf urine C) Dominance hierarchy (aggression vs.

submission) “Pecking order” in chickens


D) Circadian Rhythms (24-hour light/dark cycle keeps us awake during the day and sleepy at night) Reversed for nocturnal organisms

E) Migration (travelling for food/mating reasons Usually associated with weather or day

length Pilot Mtn. – Hawk example


F) Hibernation (energy conservation) Bear hibernates in winter

G) Estivation (energy conservation in areas where seasons don’t change) Desert snake estivates during periods of

low food sources


Learned behavior: behavior changes through practice or experience Increased brain power = Increased

capability for learned behavior 5 major types

Animal Behavior (Ch. 33) Type 1: Habituation

Animal gets “used to” a stimulus. No reward or punishment is involved. Ex: A horse gets used to cars driving by the field.

Type 2: Imprinting Babies recognize a “mother” during specific window

of youth. It is possible for one species of “mother” to be

imprinted on another species of baby.


Type 3: Trial & Error Improve quality of behavior-related product

with each trial. Bird nests…first try—glass bottles; fifth try

—twigs and grass Type 4: Classical Conditioning

“Pavlov’s response”…learn by association Bell rings food is presented….bell is

associated with food


Type 5: Insight Applying previous experience to a new

situation Mathematics & other “higher thinking” Chimp & 2-pole example


Communication: 1) Sound (bird song) 2) Sight (mating dance) 3) Touch (human approval…”pat on the

back”) 4) Smell (ant trails leading back to nest)

PHEROMONES 5) Language (use of symbols to express

ideas)

what is biology? science: a way of using organized evidence to learn about the natural world. ...

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