Unit 5 Practice Test Answers

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1.) The complex of DNA and protein that makes up a eukaryotic chromosome is
properly called _______________.
a. A chromatid
b. A chloroplast
c. Chromatin
d. A centrosome
2.) If an intestinal cell in a grasshopper contains 24 chromosomes, a
grasshopper sperm cell would contain __________ chromosomes
a. 3
b. 6
c. 12
d. 24
e. 48
3.) Chromatids are __________.
a. Held together by the centrioles
b. Identical copies of each other if they are part of the same chromosome
c. The bacterical equivelent of aeukaryotic chromosomes
d. Composed of RNA
4.) At which stage of mitosis are chromosomes lined up in one plane in
preparation for their separation to opposite poles of the cell?
a. Prophase
b. Metaphase
c. Anaphase
d. Telophase
5.) What is a locus?
a. The precise location of a gene on a chromosome
b. A structure that appears during prophase I and consists of 2 paired
genes
c. The precise DNA sequence of a gene
d. A cell with two chromosome sets
6.) Sister chromatids _______________.
a. Are only involved in mitosis
b. Are pairs of chromosomes, one of which comes from the father and
the other from the mother
c. Are identical copies of each other formed during DNA synthesis
d. Have the same gene loci but may have different alleles of some genes
e. Are only involved in meiosis
7.) Which of the following statements about homologous chromosomes is
correct?
a. They have genes for the same traits at the same loci
b. They pair up in prophase II
c. They are found in haploid cells
d. A and C
8.) Synapsis occurs during __________.
a. Anaphase I
b. Prophase I
c. Prophase II
d. Metaphase I
9.) Which of the following occurs during anaphase II?
a. Homologs separate and migrate towards opposite poles.
b. Sister chromatids separate and migrate towards opposite poles
c. Nuclei re-form
d. Chromosomes line up in one place
10.)
Which of the following occurs during telophase I?
a. Homologs separate and migrate towards opposite poles.
b. Sister chromatids separate and migrate towards opposite poles
c. Nuclei re-form to create 4 haploid cells
d. Chromosomes line up in one place
11.)
A=big apples, R=red apples, a=small, and r=yellow. You have one tree
that produces big yellow apples and another tree that produces small red
apples. When the two are crossed, you find that half of the new trees
produce big red apples and half produce big yellow apples. What are the
genotypes of the parents?
a. AArr and aaRr
b. Aarr and aaRr
c. AARr and Aarr
d. Aar and AaRr
e. AaRr and aarr
12.)
Physically, what are different alleles?
a. Different DNA sequences found at the same locus on sister chromatids
b. Different particles found in gametes
c. Different phenotypes for a particular character
d. Different DNA sequences found at the same locus on homologous
chromosomes
13.)
Pea plants are tall if they have the genotype TT or Tt, and they are
short if they have the genotype tt. A tall plant is mated with a short plant.
Which outcome indicated that the tall parent plant was heterozygous?
a. All the offspring are short
b. All the offspring are tall
c. The ratio of tall offspring to short is 3:1
d. The ratio of tall offspring to short is 1:1
14.)
If the two traits that Mendel looked at in his dihybrid cross of smooth
yellow peas with wrinkled green peas had been controlled by genes that
were located near each other on the same chromosome, then the F2
generation __________.
a. Would have contained four phenotypes in a 9:3:3:1 ratio
b. Would have contained only individuals that were heterozygous at
both loci
c. Would have deviated from the 9:3:3:1 phenotypic ratio
d. Would have contained no individuals that were heterozygous at both
loci.
15.)
The law of independent assortment __________.
a. States that the alleles at different loci segregate independently from
one another during a dyhibrid cross
b. Can account for a 9:3:3:1 ratio seen in the F2 generation
c. Applies only to genes that are present on different chromosomes
d. The first and second answers are correct
e. The first, second, and third answer are correct
16.)
If a heterozygous plant is allowed to self-pollinate, what proportion of
the offspring will also be heterozygous?
a. ¼
b. 1/3
c. ½
d. 2/3
17.)
A red bull is crossed with a white cow and all of the offspring are roan,
and intermediate color. This is an example of ___________.
a. Controlled by multiple alleles
b. Codominance
c. Polygenic
d. Incomplete dominance
18.)
A woman with type O blood is expecting a child. Her husband is type
A. Both the woman’s father and her husband’s father have type B blood.
What is the probability that the child will have type O blood?
a. 100%
b. 75%
c. 50%
d. 25%
e. 0%
19.)
In people with sickle-cell disease, red blood cells break down, clump,
and clog the blood vessels. This leads to physical weakness, heart failure,
joint pain, and brain damage. Such a suite of symptoms can be explained by:
a. The polygenic nature of sickle-cell disease
b. The pleiotropic effects of the sickle-cell allele
c. A bacterial infection interacting with the sickle-cell allele
d. Side effects of the drug used to cure this disease
20.)
The chromosome theory of inheritance states that __________.
a. Genes occupy specific positions on chromosomes
b. Homologous chromosomes segregate from each other during meiosis
c. Chromosomes assort independently during meiosis
d. The first, second, and third answers are correct
21.)
Which of the following is NOT a characteristic of Discovery Science?
a. Careful observation of nature
b. Data may be qualitative or quantitative
c. Determined by conducting experiments
d. May focus on current phenomena or historical events
22.)
Which of the following describes hypothesis-based science?
a. Focuses on explaining nature
b. Focuses on describing nature
c. Involves the testing of a hypothesis
d. A and C
23.)
When in the cell cycle is the genome (DNA) replicated?
a. Prophase
b. Prometaphase
c. S stage
d. DNA is replicated constantly throughout the cell cycle
24.)
What is crossing over associated with?
a. Synapsis
b. Metaphase I
c. Chiasmata
d. A and C
e. None of the above
25.)
Which of the following is a false statement about linked genes?
a. Are located on the same chromosome
b. Do not separate independently in gamete formation
c. Separate independently in gamete formation
d. Tend to be inherited together
e. C & D
26.)
Which statement accurately describes recombination frequency?
a. The more frequently recombination happens between two genes, the
closer together the loci are
b. The more frequently recombination happens between two genes, the
farther apart the loci are
c. The frequency of recombination has nothing to do with the distance
between two genes on a chromosome
d. None of the above
27.)
Upon arriving on Pluto, you discover a new race of aliens. You
observe that Plutonions range from having no orange spots at all to being
almost completely covered in orange spots, with a whole spectrum of
orange-spottedness in between. Assuming the Plutonions are a sexually
reproducing diploid species, which of the following is a reasonable guess
concerning the inheritance pattern of the orange spot trait?
a. Incomplete Dominance
b. Pleiotropy
c. Polygenetic Inheritance
d. Multiple alleles
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