AP Biology Mid-Term Exam Practice Problems Part I: Biochemistry, Cells and Transport
A. Chemistry of Life
1. How do the unique chemical and physical properties of water make life on earth possible?
2. How do cells synthesize and breakdown macromolecules?
3. How do structures of biological molecules relate to their function (carbs, proteins, lipids, DNA)?
4. What are the similarities and differences between prokaryotic and eukaryotic cells?
5. What is the evolutionary relationship between prokaryotic and eukaryotic cells?
6. How does compartmentalization help a cell’s functions?
7. How are the structures of the various subcellular organelles related to their functions?
8. What is the current model of molecular architecture of membranes?
9. How does the structure of membranes provide for transport and recognition?
10. What are various mechanisms by which substances can cross the membrane?
11. Draw a concept map showing the connections between the following terms: Atom, Compound,
Carbohydrate, Lipid, Protein, Nucleic Acid, Organelles, Nucleus, Mitochondria, Cell membrane, Golgi
Apparatus, ER, prokaryotic cell, eukaryotic cell
12. Draw a concept map on Cell Transport. Include all important terminology.
13. How does the method of salt or sugar curing(a process in which meat is packed in salt or sugar)
help to preserve the meat?
14. After the third Punic War the Romans threw salt on the farmland around Carthage. What was
the biological consequence of this action? Explain.
15. A plant cell, when initially placed in pure water, has an osmotic potential of -4 bars and a
pressure potential of +2 bars.
a. Which way will water diffuse?
b. When will net diffusion stop?
c. When equilibrium is reached, what are the cell's osmotic potential and pressure potential
values?
16. A protozoan is placed in a 0.5 M sucrose solution at 27°C. Assume the cell has an initial
osmotic potential of -2 bars. Because it lacks a cell wall, it cannot generate a turgor pressure
and will always have a pressure potential of 0.
a. When the cell is placed in a sucrose solution, which way will water diffuse?
b. When will net diffusion stop?
c. What will be the appearance of the cell when equilibrium is reached?
d. What will be the cell's osmotic potential and pressure potential values at equilibrium?
17. Use the diagram at right and the equation ψs = -icRT calculate the osmotic and pressure
potentials of each solution at equilibrium. Temperature = 27° C.
AP Biology Review Part 2: Energy Conversions & Enzymes and Cell Communication
1. How do the laws of thermodynamics relate to the biochemical processes that provide energy to living
systems?
2. How do enzymes regulate the rate of chemical reactions?
3. How does the specificity of an enzyme depend on its structure?
4. How is the activity of an enzyme regulated?
5. What is the role of ATP in coupling the cell’s anabolic and catabolic processes?
6. How does chemiosmosis function in bioenergetics?
7. How are organic molecules broken down by catabolic pathways?
8. What is the role of oxygen in energy-yielding pathways?
9. How do cells generate ATP in the absence of oxygen?
10. How does photosynthesis convert light energy into chemical energy?
11. How are the chemical products of the light-trapping reactions coupled to the synthesis of carbohydrates?
12. What kinds of photosynthetic adaptations have evolved in response to different environmental conditions?
13. What interactions exist between photosynthesis and cellular respiration?
14. Make a concept map to relate the following terms: catabolic, anabolic, enzymes, photosynthesis,
light dependent reaction, light independent reaction, cell respiration, glycolysis, krebs, etc, and
fermentation.
15. Make a concept map to relate the following terms: unicellular, multicellular, local regulators, long
distance regulation, contact, receptor, signal transduction, enzyme cascade, response
16. Under laboratory conditions, muscle cells were broken up and separated into fractions of
mitochondria and cytoplasm in an attempt to learn more about cellular respiration. Each fraction
was incubated with glucose or pyruvate. Tests were carried out during incubation for the
presence of either carbon dioxide or lactic acid. The results are shown below:
a. What does the presence of lactic acid in a sample indicate about what process is occurring in
each cell fraction?
b. Explain why lactic acid was produced by the cytoplasm fraction incubated with glucose, but not
the mitochondrial fraction.
c. Why was no carbon dioxide produced by either fraction incubated with glucose?
d. Why did the cytoplasm fraction produce lactic acid in the presence of both glucose and
pyruvate?
e. Why did the mitochondria produce carbon dioxide in the presence of pyruvate but not in the
presence of glucose?
AP Biology Practice Problems Part 3: Evolution
1. As a field researcher you are sent to the Arizona desert to study the prairie dog species C.
ludivincianus to determine if the population is in Hardy-Weinberg equilibrium. Specifically, you are
studying this population with respect to the gene that determines the coat color in C. ludivincianus.
This trait is coded for by a single gene (the NDY6 gene) with two alleles (N, n) and is passed
down from one generation to the next. After sampling 170 of these prairie dogs, you find that 36%
of the C. ludivincianus population is homozygous recessive for coat color. Assuming that the
population is in Hardy-Weinberg equilibrium…
a. What is the allele frequency of the N allele?
b. What is the frequency of homozygous dominant prairie dogs?
c. What is the frequency of heterozygous prairie dogs?
d. What conditions must be being satisfied?
2. Walking through the forest, you find a large population of toadstools. From your extensive
knowledge of the kingdom fungi, you know that the allele for being spotted (S) is dominant over
the allele for being plain (s).
a. In this population of 1007, you find 14 toadstools that are not spotted. What are the allele
frequencies?
b. In a different forest, you find a somewhat smaller population of 549. Through genetic testing,
you determine that there are 308 homozygous spotted, 206 heterozygous, and 34
homozygous plain toadstools. Is this what you expected? (Test with the Chi square.) If not,
what are the allele frequencies of this population?
Spotted SS (p2)
Spotted Ss (2pq)
Plain ss (q2)
Total
3. In a population of Venus fly traps in North Carolina, you observe 150 that can eat large flies, and
400 that can eat only small flies.
a. If the ability to eat large flies (s) is recessive, what is the allele frequency?
b. Back in town, you visit a specialty store that sells Venus fly traps. Of the 56 plants in the store,
how many do you expect to eat large flies?
c. You count and see that 25 can eat large flies. Is this what you expected? (Test with the Chi
square.) If not, what are the new allele frequencies?
4. For the past 10 to 25 years, farmers have planted crop seeds that have been genetically modified
to withstand treatment with a common weed killer called Roundup®. This allows the farmers to
spray their fields to get rid of weeds without harming their crops. Recently, more and more farmers
have discovered that their fields have Roundup-resistant pigweed growing along with their crop.
Describe what has most likely happened over time to lead to this.
5. Peppered moths have wings that vary in color, ranging from white to dark gray. During the
Industrial Revolution through the mid-20th century, factories and power plants, which burned coal,
produced large quantities of soot and smog. Near industrialized areas, black powder covered
surfaces, including the moth habitat.
a. Use this information to explain the changes seen in light and dark peppered moths from
1800-1950, as shown in the graph below.
b. Propose an explanation for the return of the peppered moth population to more light than
dark moths by the year 2000.
6. Five new species of bacteria were discovered in Antarctic ice core samples. The nucleotide (base)
sequences of rRNA subunits were determined for the new species. The table below shows the
number of nucleotide differences between the species. Draw a phylogenetic tree indicating the
relatedness of these 5 species.
Species
1
2
3
4
5
1
-
2
2
-
3
23
24
-
4
19
19
23
-
5
17
18
23
1
-
7.
a. Discuss the differences in diversity among the plants shown in the graph.
b. If a scientist wanted to determine if two understory trees in the field were the same species,
what pieces of evidence would she gather and how would these inform her conclusion?
8) Which of the following conclusions is best supported by the cladogram on the right?
(A) Species P and Q are equally related to species T.
(B) Species P and T do not share a common ancestor.
(C) Species S evolved from species R.
(D) Species S is more closely related to species T than to species R.
9) Cladograms (a type of phylogenetic tree) constructed from evidence from molecular data are based on similarities in
(A) mutations to homologous genes
(B) the pattern of embryological development
(C) biochemical pathways
(D) morphology
10)Four new species of plants were discovered in Greenland ice core samples. The nucleotide (base) sequences of rRNA
subunits were determined for the new species. The
Species
1
2
3
4
table below shows the number of nucleotide
1
1
5
6
differences between the species. Create a
Cladogram for the data provided.
2
1
6
7
3
5
6
1
4
6
7
1
-