274 ❯ STEP 5. Build Your Test-Taking Confidence
- A murder trial court case ended up ruling against
the defendant because of DNA evidence found at
the crime scene and analyzed in the forensics lab.
A. Describe how a gel electrophoresis experi-
ment works and is set up, why things move
the way they do, and why the gel would be
able to prove, beyond a shadow of a doubt,
that the defendant was indeed guilty as
charged.
B. Gel electrophoresis is also used to determine
court paternity cases. Describe how a gel
could be used to prove whether an individ-
ual is the father of a particular baby. Include
all the pertinent experimental laboratory
procedures in your description.- Speciation, the process by which new species are
formed, can occur by many mechanisms. Explain
howthreeof the following are involved in the
process of species formation.
A. Geographic barriers
B. Polyploidy
C. Balanced polymorphism
D. Reproductive isolation
3. Life on Earth is made possible because of certain
unique characteristics of water. Choose two
characteristics of water.
A. For each characteristic that you choose,
identify and define the property.
B. Describe one example of how the property
affects the functioning of living organisms.
4. Evolution is the change in allele frequencies in a
population over time. This can occur through a
variety of mechanisms, three of which are listed
below.- Natural selection
- Genetic drift
- Mutation
A. Define twoof the three forces of evolution
listed above and give an example.
B. You are studying a population of field mice
that includes individuals with light and dark
brown coats. Every six months you perform
capture/recapture experiments to census the
proportion of light and dark individuals.
The following numbers indicate the per-
centage of dark-coat individuals caught in
each successive census over the course of five
years:
96, 94, 95, 91, 93, 95, 74, 73, 77, 76
Explain which of the three processes of evolution
is most consistent with this data, and give a
hypothetical explanation for the observed
changes in phenotypic frequencies in this mouse
population.
AP Biology Practice Exam 1: Section II
FREE-RESPONSE QUESTIONS
Time—1 hour and 30 minutes
(The first 10 minutes is a reading period. Do not begin writing until the 10-minute period has passed.)
Questions 1 and 2 are long free-response questions that should require about 20 minutes each.
Questions 3–8 are short-response questions that should require about 6 minutes each.
Outline form is not acceptable. Answers should be in essay form.ABC