Download Practice Test - RHS AP Biology

Unit 4: Mechanisms of Inheritance – Review Test
1. There are four human blood types: A, B, AB, and O. Each person has one of these
blood types, depending on the antigen(s) present on the surfaces of their red
blood cells. This is a genetic trait. The chart below shows what antigens are
present for each blood type.
Blood Type
Antigen on Surface of RBC’s
A
Antigen A
B
Antigen B
AB
Antigen A and Antigen B
O
none
A man with blood type O and a woman with blood type AB have a child with the blood
type A. Which of the following describes how this inheritance pattern is possible?
a. The child inherited an A allele from each parent, both of whom are heterozygous
for that trait.
b. The gene is sex-linked, so the child received an A allele on her father’s X
chromosome.
c. A crossing over event occurred during meiosis that removed the O and AB
alleles from the child’s DNA.
d. The A allele is dominant in this family so the trait appears due to the recessive
alleles the parents carry.
2. Sickle cell anemia is a blood disorder that affects the ability of RBC’s to deliver
oxygen throughout the body. The table below shows the effects of various
genotypes on the susceptibility for anemia as well as malaria. Note that persons
that are heterozygous for the two alleles have a reduced chance of dying from
either disorder.
Genotype
RR
Rr
rr
Blood Cell Shape
Normal
Normal
Sickle-shaped
Sickle cell anemia
No
No
Yes
Vulnerability to
Malaria
Yes
No
No
The allele frequency of the recessive allele r is 9% in a particular population.
Which scenario would best predict what happens if malaria infections in this
population dramatically increased?
a. The R allele frequency will increase because normal alleles are dominant and
will improve survival.
b. The r allele frequency will increase because Rr individuals will survive better
than RR individuals.
c. Both R and r allele frequencies will decrease because there are selective
pressures working against both of them.
d. There will be no change in allele frequencies because the process of natural
selection works on both alleles equally.
3. The history of the discovery of the DNA model is based on a collection of findings
from multiple scientists. Although they didn’t all collaborate, their individual
findings lead to the overall knowledge of the structure of DNA that was finally
determined by James Watson and Francis Crick. Below is a list of
accomplishments that lead to our view of DNA:
-Chargaff found that AT and GC ratios are constant across phyla
-Griffith found that a nonliving substance would transform living cells
-Pauling proposed that DNA consists of a triple-helix structure
-Levene identified the chemical structure of nucleotides
-Hershey and Chase identified DNA as the carrier of hereditary information
Which finding lead Watson and Crick to the conclusion that DNA is a double
helix?
a.
b.
c.
d.
Levene’s identification of nucleotide structures
Griffith’s transformation theory
Hershey and Chase’s DNA analysis
Chargaff’s nucleotide ratios
4. Several human inheritable diseases are caused by mutation and then passed on
to subsequent generations. Anyone who inherits the mutation is destined to
suffer from the disease and then has a 50% chance of passing it on to their
children. Which of the following is an ethical question posed about this idea?
a.
b.
c.
d.
How can researchers use today’s technology to understand these diseases?
Are genetic tests for these inheritable diseases reliable?
Could we test human embryos for the mutations and select which survive?
What kinds of environmental factors may lead to mutations that cause these
diseases?
5. In Gregor Mendel’s experiments, pea plants produced round or wrinkled seeds.
When he self pollinated certain plants, he produced pods with 100% round seeds
as well as plants that have 100% wrinkled seeds. When each of these plants are
cross pollinated, the resulting plant produced approximately 75% round and 25%
wrinkled seeds.
Which of the following statements supports the claim that heritable information
passes from one generation to the next through meiosis followed by fertilization?
a. There is insufficient information to support this premise.
b. The P1 plants support the claim by showing that multiple traits do not show
up when they are self pollinated.
c. The F1 plants support the claim by showing that the wrinkled trait remains
present after cross pollination.
d. The F1 plants support the claim by showing that purity is preserved during
the process of meiosis and fertilization.
Free Response 1
In addition to seed shape (R = round and r = wrinkled), pea plants are either tall (T) or
short (t). The diagram below shows the distribution of alleles in two chromosomes in
two pea plants that cross-pollinate.
R
r
t
R
T
T
Genotype:
Female
RR TT
r
t
Male
rr tt
Phenotype:
Round, Tall
Wrinkled, Short
In the box at the top of the next page, DRAW a diagram to illustrate the basic
steps involved in gamete formation in the female parent. Label each step.
(5 points)
DRAW a diagram to illustrate gamete formation in the male parent. Label each step. (5)
DRAW a diagram to illustrate a fertilization event that produces one possible zygote.
DESCRIBE the genotype and phenotype of this zygote. (4 points)
DESCRIBE how many other different zygotes would have been possible. Explain your
reasoning. (2 points)
DESCRIBE how the number of possible zygotes would have been different if one of the
plants had the genotype RRTt. Explain your reasoning. (2 points)
Free Response 2
Two traits in cats are eye color (B = blue and b = yellow) and length of tail (T = long and
t = short).
CALCULATE the number of different gametes produced by a female cat with the
genotype BBtt. (1 point)
CALCULATE the number of different gametes produced by a male cat with the genotype
bbTT. (1 point)
CALULATE the number of different genotypes represented in the F1 generation
produced from a cross between a female BBtt x male bbTT. (1 point)
CALULATE the number of different gametes produced by a female cat or male cat with
the genotype BbTt. (1 point)
DRAW a Punnett square to show the results of a cross between a female BbTt and male
BbTt. (8 points)
Suppose the cat pair have 64 kittens. How many of the F1 organisms would be expected
to have blue eyes and short tails? (1 point)
Suppose the cat pair have 32 kittens. CALCULATE the number that would be expected
to have yellow eyes and short tails. (1 point)
Suppose the cat pair have 32 kittens. CALCULATE the number that would be expected
to have yellow eyes and long tails. (1 point)
Suppose the cat pair have 32 kittens. CALCULATE the number that would be expected
to have blue eyes and long tails. (1 point)