270 ❯ STEP 5. Build Your Test-Taking Confidence
48.Which of the following processes may be
occurring in this population, given the allele
frequencies?
A. Directional selection
B. Homozygous advantage
C. Hybrid vigor
D. Allopatric speciation
Questions 49–51: An eager AP Biology student
interested in studying osmosis and the movement of
water in solutions took a dialysis bag containing a
0.5 M solution and placed it into a beaker containing
a 0.6 M solution.
49.After the bag has been sitting in the beaker for a
while, what would you expect to have happened
to the bag?
A. There will have been a net flow of water out
of the bag, causing it to decrease in size.
B. There will be have been a net flow of
water into the bag, causing it to swell in size.
C. The bag will be the exact same size because
no water will have moved at all.
D. The solute will have moved out of the dialy-
sis bag into the beaker.
50.If this bag were instead placed into a beaker of
distilled water, what would be the expected
result?
A. There will be a net flow of water out of the
bag, causing it to decrease in size.
B. There will be a net flow of water into the
bag, causing it to swell in size.
C. The bag will remain the exact same size
because no water will move at all.
D. The solute will flow out of the dialysis bag
into the beaker.
51.Which of the following is true about water
potential?
A. It drives the movement of water from a
region of lower water potential to a region of
higher water potential.
B. Solute potential is the only factor that deter-
mines the water potential.
C. Pressure potential combines with solute
potential to determine the water potential.
D. Water potential alwaysdrives water from an
area of lower pressure potential to an area of
higher pressure potential.
Questions 52–54 all use the following pedigree, but
are independent of each other:52.If the pedigree is studying an autosomal recessive
condition for which the alleles are A and a, what
was the probability that a child produced by
parents A and B would be heterozygous?
A. 0.0625
B. 0.1250
C. 0.2500
D. 0.5000
53.Imagine that a couple (C and D) go to a genetic
counselor because they are interested in having
children. They tell the counselor that they have a
family history of a certain disorder and they want
to know the probability of their firstborn having
this condition. What is the probability of the
child having the autosomal recessive condition?
A. 0.0625
B. 0.1250
C. 0.2500
D. 0.3333
54.Imagine that a couple (C and D) have a child
(E) that has the autosomal recessive condition
being traced by the pedigree. What is the proba-
bility that their second child (F) will have the
autosomal recessive condition?
A. 0.0625
B. 0.1250
C. 0.2500
D. 0.5000A B