2013 AP Biology Final Exam Review
1. The presence of covalently bonded carbon atoms is what makes organic molecules different from
inorganic molecules.
2. Pyrimidines are the sugars in nucleic acids that have single-ring structures; purines have double-ring
structures
3. The phosphate group represents the part of the DNA molecule that creates a slightly negative charge.
4. DNA contains a hydrogen on the 2’ carbon (see #5 below), while RNA contains a hydroxide group on
the 2’ Carbon (See #4 below)
5. The bonds between the bases in DNA and RNA are hydrogen bonds, which are weak, allowing for easy
separation during replication and protein synthesis.
1
2
3
4
5
6. The first molecule is a purine, because of its double ring structure.
7. The second and third molecules are pyrimidines because of their single ringed structure
8. The solid curve and the dashed curve represent
alternate pathways of the same reaction. Know what
each letter represents in the graph above:
a.
Reactants
b.
Activation energy with enzyme
c.
Activation energy without enzyme
d.
Net energy change
e.
Products
9. Study the structure of the amino acid. Make sure
you know the functional groups
of the amino acid: carboxyl
group (Carbon double bonded to oxygen, and a hydroxide…OH), and an amino group
(Nitrogen with single bonds to two hydrogens), and an R group which is the
distinguishing factor in amino acids.
10.The kind of bond that holds oxygen and hydrogen atoms together in a water
molecule is a covalent polar, while the type of bond that holds multiple water molecules
together is hydrogen.
Evolution and Origins of Life:
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Have an understanding of the Hardy-Weinberg Principle, and be able to calculate gene frequencies
within the parameters of the Hardy-Weinberg Equilibrium.
p2 + 2qp + q2 = 1
p= dominant allele; q= recessive allele; p2= homozygous dominant genotype; q2= homozygous
recessive genotype; 2pq= heterozygous genotype. ALWAYS start with the given, which in most
cases will either be the frequency of the homozygous recessive allele, or the frequency of the
homozygous recessive genotype. Then, calculate everything else.
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The five basic assumptions of the hardy-Weinberg Equilibrium are:
 Population infinitely large, and genetic drift is not occurring
 No gene flow (migration in or out) occurring in a population
 No mutation occurring
2013 AP Biology Final Exam Review
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 No natural selection occurring
 All mating is totally random
We define an individual’s “fitness” by the number of viable offspring it produces.
Evidence supporting evolution:
 Comparative biochemistry: Shared DNA; immunity to disease: horse antibodies
 Comparative anatomy and physiology: homologous structures similar structure, yet may
have different function, such as the wing of a bat, and the arm of a human
 Comparative embryology: Developmental similarities
 Vestigial Structures: structures that once had a purpose, but no longer do
 Analogous structures have similar function, but different structure, such as a butterfly wing,
and a bird wing. This shows that organisms can evolve these features and have NO direct
evolutionary link.
Convergent evolution occurs when many organisms all over the world resemble one another, but
have no evolutionary link. The environments in which they live are very similar, and have “directed”
their evolutionary patterns in a consistent manner, so they may look very similar, yet have very
different evolutionary backgrounds and ancestors. Examples include: spiny anteaters, and echidnas.
Graph A shows a type of
selective pressure known as
A
B
C
“disruptive” selection. This
pattern of selection favors the
extremes of a trait. Graph B
shows a type of selective
pressure known as “directional” selection, where one extreme is favored over another.
Graph C shows the average or intermediate trait is selected for in this environment.
Allopatric Speciation occurs when biological populations become isolated due to geographical
changes such as mountain building. This type of speciation occurs as a direct result of geographic
isolation. Sympatric speciation occurs when new species evolve from a single ancestral species
while inhabiting the same geographic region. These species are VERY closely related, yet have
selected slightly different niches to fill. Examples include the cichlid diversity in volcanic crater
lakes, where some have adapted to lighted zones where their preferred food is plentiful, and others
still live in the deep benthic zones, where their preferred food is found.
Types of isolation:
 Temporal: has to do with time. Mating may occur at different times of the year.
 Behavioral: has to do with mating rituals and pair-bonding behaviors. Female birds may
prefer certain songs, or dances.
 Reproductive: behaviors and physiological processes that prevent the members of two
different species that cross or mate from producing offspring.
i. Isolation mechanisms that occur before breeding or copulation (pre-zygotic
isolation)
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Temporal or habitat isolation: a sympatric form of speciation whereby two populations of
organisms are separated by the “time” of year in which they mate.
Sexual isolation by behavior or conduct
Mechanical isolation: Physically unable to mate
Gametic Isolation: Gametes do not recognize one another
ii. Isolation mechanisms that occur after breeding or copulation (post-zygotic
isolation)
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Zygote mortality and non-viability of hybrids
 Hybrid sterility: example: mules
Sexual selection: many animals develop features whose function is not to help individuals survive,
but help them to maximize their reproductive success. This can be realized in two different ways:
o by making themselves attractive to the opposite sex (intersexual selection, between the
sexes…largely driven by the females of the species)
o By intimidating, deterring or defeating same-sex rivals (ornaments and weapons…largely
driven by the males of the species).
2013 AP Biology Final Exam Review
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The environment that an organism lives in often determines what new mutations are favorable, or
advantageous to that organism, or whether it puts the organism at a disadvantage. The English
Peppered Moth exists in two phenotypes; that of lightly colored, and darkly colored. Directional
selection is at work, in that over time, one variant over the other is selected for (during the industrial
revolution). This variation is very important in illustrating the importance of the environment is
selecting exactly what trait is advantageous
One gas that is important to aerobic life today that was not present in early Earth’s atmosphere is O 2
Genetic Drift: along with natural selection, mutation, and migration—is one of the basic
mechanisms of evolution. In each generation, some individuals may, just by chance, leave behind
a few more descendants (and genes, of course!) than other individuals. The genes of the next
generation will be the genes of the “lucky” individuals, not necessarily the healthier or “better”
individuals. That, in a nutshell, is genetic drift. It happens to ALL populations—there’s no
avoiding the vagaries of chance. It happens much faster in small populations, however, than large
ones. Two extreme cases of genetic drift include bottlenecking and founder effect.
 Bottlenecking: Population bottlenecks occur when a population’s size is reduced for at least
one generation. Because genetic drift acts more quickly to reduce genetic variation in small
populations, undergoing a bottleneck can reduce a population’s genetic variation by a lot,
even if the bottleneck doesn’t last for very many generations.
 A founder effect occurs when a new colony is started by a few members of the original
population. This small population size means that the colony may have:
 reduced genetic variation from the original population.
 a non-random sample of the genes in the original population.
Humans may ascribe to a God some natural events they do not understand, and may not have a
scientific explanation for. One non-scientific explanation of natural disasters is punishment by a
God for bad behavior.
Endosymbiont theory states that early prokaryotic life forms (bacteria) consumed other prokaryotes,
which resisted digestive processes, and then developed a symbiotic (mutualistic) relationship with
them once they were inside. Then, these symbionts became “organelles”, and the first eukaryotic
cells were created.
Fossil record indicates that origins and progressive evolution of life occurred in the following order:
 Prokaryotes; Eukaryotic Protists; fungi; aquatic invertebrates; aquatic plants and fish; terrestrial
plants (non-angiosperms); amphibians; reptiles; flowering plants; birds; mammals; humans
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A cladogram like the one to the right, shows evolutionary relationship based
upon similar structures and perhaps even DNA
today. In the cladogram to the right, the
structures (such as amniotic egg) are represented
along the axis to the right. All organisms
branching beneath that point do not exhibit an
amniotic egg. All organisms above it, do. So, in this
cladogram, the organisms that exhibit an amniotic egg are
the primates, rodents, crocodiles, dinosaurs and birds. This
also shows that birds and dinosaurs are more closely related to
crocodiles than they are to rodents, primate, amphibians, and fish.
All animals in the cladogram are vertebrates.
2013 AP Biology Final Exam Review
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Know the structure of the nucleotides that make up DNA, and RNA (and ATP). The phosphate
group along the backbone of the molecule is what is responsible for the
slightly negative charge of the DNA molecule.
Between the bases, hydrogen bonds form (double between A
and T; triple between C and G). These bonds are easily broken
during replication and protein synthesis.
Hydroxide (OH-) found on 2’ carbon = Ribose
Hydrogen (H) found on 2’ carbon= Deoxyribose
Water molecules are composed of two hydrogen atoms
covalently (polar) bonded to an oxygen molecule. Each water
molecule is linked together with a hydrogen bond, which is
really a loose association between polar molecules.
Carbohydrate storage in humans is accomplished in the liver,
in the form of glycogen. NO STARCH can be stored in humans.
Starches may be stored only in plants, and some plant-like protists.
Know the four structures of proteins and the
significance of each. Primary structure:
sequence of amino acids; Secondary: helix or
pleated sheet; Tertiary: joining helix and
pleated sheet…most important to function;
Quaternary: when more than one tertiary
structure is united together (see diagram to
right)
Know that dehydration synthesis (a
condensation reaction) is used to “BUILD”
biomolecules. Hydrolysis is the process that
“TEARS” them down. In dehydration
synthesis (condensation), water is added, and
in hydrolysis, water is taken away.
Know the properties of water.
Polar covalent
Universal solvent
Adhesion/cohesion
High specific heat
Denser in liquid form than in solid form
Within the lipids you will find:
Steroids: cholesterol…fluidity in plasma
membrane
Waxes: protective cuticle in plants to prevent
desiccation
Pigments: produce colors in organisms
Fats: energy storing molecules
Review the following biomolecules, know and understand their structure and function.
Amino Acid
Lipid:
Steroid/Cholesterol
Carbohydrate
Lipid: Triglyceride
Nucleic Acid: ATP