1. AP Biology Exam Review Notes
Week One

2. Evolution – Evidence for Evolution
Direct observations
Fossil record
Homologies
Homologous structures
embryonic structures
vestigial organs
molecular homologies
convergent evolution (analogous structures)
Biogeography

3. Evolution – Natural Selection
Evolution is changes in species over time
Heritable variations exist within a population
Variations result in different reproductive success and eventually changes in the genetic comp of population
Predator and Sexual selection
NS explains how adaptations arise
Adaptation – characteristic that enhances an individuals ability to survive and reproduce
Survival of the fittest
Artificial selection – species modified by humans
Populations evolve, individuals do not!

4. Darwin’s finches Differences in beaks allowed some finches to…
successfully compete
successfully feed
successfully reproduce
pass successful traits onto their offspring

5. Evolution – Cladograms and phylogeny
Phylogeny – evolutionary history of a species or group of related organisms
Uses evidence from fossils, morphology, genes, and molecular similarities
Illustrates speciation and shows common ancestors
Cladogram – diagram that shows a pattern of shared characteristics
Clade shows a species and its ancestral descendents
Based on common characteristics

7. Evolution – Genetic Drift
One of the factors that can alter allele frequencies, others are NS and gene flow
GD: unpredictable fluctuations in allele frequencies from one generation to the next
Smaller population greater the chance for GD
Founder and bottleneck, both random and non adaptive
Alter the frequency and distribution of phenotype
Disruptive
Directional
Stabilizing

9. Evolution – Primitive Earth
Earth 4.6 BYO
2.7 BYO oxygen due to photosynthesis
2.1 BYO Eukaryotes (Endosymbiotic hypothesis)
500 MYO Cambrian explosion of diversity of life
Oparin and Haldane hypothesis, primitive soup from which life arose
Small organic molecules formed
These molecules formed macromolecules
Packaged into protocells
Self replicating molecules made inheritance possible

10. Evolution – Speciation
Process by which new species arise, shows diversity and unity of life
Reproductive isolation
Prezygotic – habitat, behavioral, temporal, mechanical, and gametic
Postzygotic- reduced hybrid viability or fertility
Allopatric: new species b/c of geographic isolation
Sympatric: new species w/o geographic isolation
Adaptive radiation
Speciation can be gradual or punctuated

11. Evolution – Hardy-Weinberg
Theorem used to describe populations that are not evolving, serves as a model or null hypothesis
5 conditions: no mutations, random mating, no natural selection, large population size, and no gene flow
p + q = 1
p frequency of dominant allele
q frequency of recessive allele
p2 + 2pq + q2 = 1
p2 frequency of homozygous dominant
2pq frequency of heterozygous condition
q2 frequency of homozygous recessive

12. Using Hardy-Weinberg equation
population: 100 cats
84 black, 16 white
How many of each genotype?
q2 (bb): 16/100 = .16
q (b): √.16 = 0.4
p (B): = 0.6
p2=.36
2pq=.48
q2=.16 BB Bb bb
Must assume population is in H-W equilibrium!
What are the genotype frequencies?

13. Using Hardy-Weinberg equation
p2=.36
2pq=.48
q2=.16
Assuming H-W equilibrium BB Bb bb
Null hypothesis
p2=.20
p2=.74
2pq=.10
2pq=.64
q2=.16
q2=.16
Sampled data 1:
Hybrids are in some way weaker.
Immigration in from an external population that is predomiantly homozygous B
Non-random mating... white cats tend to mate with white cats and black cats tend to mate with black cats.
Sampled data 2:
Heterozygote advantage.
What’s preventing this population from being in equilibrium. bb Bb BB
Sampled data
How do you explain the data?
How do you explain the data?

14. Don’t be a Dodo…
Ask Questions!!

15. Biochemistry- Water Water is polar, hydrogen bonding
Cohesion and adhesion…important in transpiration
High specific heat…moderates temperature
Less dense as it freezes…floats allowing for aquatic animal life
Important solvent and buffer

16. Which of the following is responsible for the cohesive property of water?
A)Hydrogen bonds between the oxygen atoms of two adjacent water molecules B) Covalent bonds between the hydrogen atoms of two adjacent water molecules C) Hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule D) Covalent bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule
Answer “C”

17. Biochemistry – Carbon and Functional Groups
Carbon is a versatile atom because of its electron configuration and skeleton.
4 valence electrons single, double, or triple covalent bonds
Branched, chains, rings, isomers
Functional Groups, components of organic molecules involved in chemical reactions
Important in polarity, stabilizing tertiary protein structure, and building the macromolecules

18. Functional Groups

21. Biochemistry – Macromolecules
Monomers used to build polymers by a dehydration reaction (requires energy and enzymes)
Hydrolysis used to split large molecules
Nucleic Acids (C, H, O, N, P)
DNA and RNA
Contains genes, the blueprint for life
Nucleotides, purine and pyrimidine
Carbohydrates (C, H, O)
Glucose and fructose common monosaccharide
Important source of energy, storage, and building material
Starch and cellulose in plants, Glycogen in animals common polysaccharides

22. Biochemistry – Macromolecules
Proteins (C, H, O, N)
20 different amino acids
Every amino acid has 4 parts: amino group (-NH2), carboxyl group (-COOH), a hydrogen, and an R group (side chain)
Contains enzymes, transport proteins, & antibodies
Denaturation and specificity
Levels of protein structure: P, S, T, Q
Lipids (C, H, O)
Function as structural components of cell membranes, sources of insulation, and a means of energy storage
Includes fats, oils, phospholipids, and steroids
Saturated, unsaturated, polyunsaturated

23. Which of the following pairs of functional groups characterized the structure of an amino acid?
Amine and carbonyl (ketone)
Carboxyl and amine
Carboxyl and carbonyl (ketone)
Hydroxyl and amine
Ester and amine
Answer B

24. Biochemistry - Enzymes
Biological catalyst that lowers the activation energy to speed up a reaction without being used itself
Specificity
Induced fit
pH and temperature, cofactors and coenzymes, and inhibitors all affect activity
Allosteric, competitive, and noncompetitive

26. 93. B
94. B
95. C
96. E

27. Biochemistry – Free Energy and Thermodynamics
1st law of thermo – energy cannot be created or destroyed
2nd law of thermo – transformations increase entropy (disorder) in the universe
Open vs. closed system
Free Energy (ΔG) the energy available to do work
Loss of free energy = death
ATP powers all endergonic reactions
ΔG = ΔH – T Δ S
ΔH = Enthalpy (change in heat…exo is –ΔH and endo is +)
ΔS = Entropy
T= Temperature (Kelvin)

28. Exergonic occurs spontaneously -Increases entropy
Endergonic requires energy input
-Not spontaneous
-Decreases entropy

29. Biochemistry - Metabolism
All of the chemical reactions within an organism
Catabolism- energy released by the breakdown of molecules, exergonic…CR
Anabolism – energy consumed to build molecules, endergonic
Related to an animals size, activity, age, sex, temperature and environment
Smaller animal = higher BMR

30. Warm-Up 4/19/17 Please read the handout on the bottle neck effect.
Have your evolution notes out. We will go over the Hardy-Weinberg Problems.

31. What biomolecule is this?

32. What biomolecule is this?

33. What biomolecule is this?
What kind of reaction forms this molecule?

34. What biomolecule is this?

35. Cellular Energetics - Redox
Redox reactions release energy when electrons move closer to the more electronegative atom
OIL RIG (Oxidation is Loss, Reduction is Gain)
When a reactant is oxidized it loses electrons and energy
When a reactant is reduced it gains electrons and energy
Important in electron carriers in P and CR
Path of electron
Food  NADH  ETC  O2

36. Cellular Energetics - Summary
Photosynthesis
Occurs in the chloroplast in the stroma and across the thylakoid membrane
Autotrophs only
6CO2 + 6H2O + light energy  C6H12O6 + 6O2
Cellular Respiration
Occurs in the cytosol, mitochondrial matrix, and across the inner membrane of the mitochondria
Occurs in all living organisms
C6H12O6 + 6O2  6CO2 + 6H2O + Energy (and heat)

38. Cellular Energetics – CR Glycolysis
Occurs in cytosol
Sugar splitting…Glucose is broken down into 2 pyruvate
Must invest 2 ATP to start process
Gain 2 ATP and 2 NADH to take electrons to ETC
From here depends on if oxygen is present
Aerobic go to Krebs and ETC
Anaerobic to go fermentation

39. Cellular Energetics – CR Krebs Cycle
Occurs in mitochondrial matrix
CO2 removed from Pyruvate, coenzyme A binds to form Acetyl CoA which can enter the Krebs cycle
Each turn of Krebs requires 1 Acetyl CoA
Each turn produces CO2, Electron carriers NADH and FADH2 and ATP
At the end of Krebs the original 6 carbon molecules from glucose are all released as CO2

40. Cellular Energetics – CR ETC
Occurs across the inner membrane of the mitochondria
Electron carriers are oxidized as they move down the chain and lose energy, eventually oxygen is the final electron acceptor
As the electron carriers move their energy is used to pump H+ ions across the membrane to create a gradient
The H+ gradient causes ATP synthase to become permeable to H+ which move through phosphorylating ADP to ATP
Most ATP in CR is produced during this stage

42. Cellular Energetics – CR Fermentation
Allows the cell to use inefficient CR if there is no oxygen available
Glycolosis and reactions that regenerate the electron acceptor NAD+
Alcoholic and Lactic Acid

45. Cellular Energetics – P Light Reactions
Occurs across the thylakoid membrane
Photosystems- groups of pigment that can absorb photons in the membrane
Noncyclic phosphorylation-
P680 in PS II captures light and passed excited electrons down an electron transport chain to produce ATP
P700 in PS I captures light and passes excited electrons down an electron transport chain to produce NADPH
A molecule of water is split by sunlight, releasing electrons, hydrogen, and free O2.
Cyclic only produces ATP when there are not enough NADP to accept electrons
The whole point in the light reaction is to produce 2 things:
1) energy in the form of ATP
2) electron carriers, specifically NADPH
Both of these products, along with CO2, are then used in the dark reaction to make carbohydrates

47. Cellular Energetics – P Calvin Cycle
Uses the produces of light reaction- ATP & NADPH- to make sugar.
Also called the C3 pathway
Occurs in the stroma
Carbon fixation- CO2 is converted into carbohydrates (C6H12O6)
CO2 enters the Calvin cycle and combines with a 5-C molecule called ribulose bisphosphate (RuBP) to make an unstable 6-C compound. (Carbon Fixation) The enzyme rubisco, catalyzes this reaction.
Reduction to G3P, some GSP converted to sugar but most is regenerated back to RuBP

48. Cellular Energetics – P Adaptations
C3 plants will close stomata on hot dry days to reduced water lost by transpiration (trade off for not getting any CO2 either)
Plants like corn and sugar cane have a more efficient way to fix carbon the C4 pathway
In these plants, CO2 first combines with (PEP) to form oxaloacetate (4-C)
C4 works particularly well for plants found in hot, dry climates. It enables them to fix CO2 even when the supply is greatly diminished.
Both C3 and C4 use Calvin to fix sugars
CAM photosynthesis
Desert plants have evolved a way to perform photosynthesis when their stomates are closed;
When stomata open at night, CO2 is taken up and PEP carboxylase is used to fix CO2 into organic acid and sent to the cell’s vacuole.
During the day, light reactions supply ATP and NADPH for the Calvin cycle. organic acid is converted back to oxaloacetate and carbon dioxide is released to be used in the Calvin cycle

49. Mock Test Grid-in #4 HW
In a sheep black wool is a recessive trait. In a flock of 250 sheep, 12 sheep were found to have black wool. Assume that the population is in Hardy-Weinberg equilibrium. Calculate the percent of the population that is heterozygous for this trait. Give your answer to the nearest tenth.

50. Answer grid-in #4 HW q2= 12/250 = 0.048 q= √0.048 = 0.219
p= = 0.781
Heterozygous 2pq = 2* * = .342
Answer asked for percent! 34.2%
Acceptable range of answers

51. Stick your neck out… Ask Questions!

52. Plants - Tropisms
Plant growth response from hormones that results in a plant growing towards or away from a stimulus
Phototropism – response to light
Photoperiodism – response to length of night
Gravitropism – response to gravity
Thigmotropism – response to touch
Response to stress, predators, and pathogens

53. Plants – Plant Communication
Reception  Transduction  Response
Plants use hormonal signals to respond to the environment and enhance survival and reproductive success
Auxin, cytokinins, and gibberellins all work in cell elongation, division, and differentiation
Abscisic acid slows growth and promotes seed dormancy
Ethylene work in apoptosis, fruit ripening, and response to mechanical stress

54. Plants- Plant Anatomy Vascular plants have 2 types of vascular tissue
Xylem transports water and minerals
Phloem transports sugars, amino acids, and other organic products
Leaves increase SA of plant, main photosynthetic organ; Cuticle thick outer coating on leaves
Roots – absorb water and nutrients from the soil, anchor vascular plants

56. Plants- Transpiration and Water Potential
Transpiration – loss of water through stomata, affected by many variables
Cohesion, adhesion, and water potential pull water from the roots to the leaves
Water potential – physical property that predicts the direction in which water will flow; includes the effects of solute concentration and physical pressure
Ψ = Ψs + Ψp
Ψs = -iCRT
As solute concentration increase water potential becomes more negative
As pressure increases so does water potential
Water moves from an area of high water potential to low water potential
Flaccid, plasmolysis, and turgid

57. Plants – Adaptations to the environment
Waxy thick cuticle – prevent water loss
Huge leaves – catch more sunlight
Spines – modified leaves or stems
Flowers – attract pollinators
Fruits – aid in seed dispersal
Mycorrhizae – mutualistic relationship with fungi for nutrient absorption
Extensive root systems when in a biome characterized by fire or long shallow roots to catch water in deserts
Deciduous – loss leaves in winter
Different placement of stomata depending on aquatic or land plant