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AP Biology 15, 16 Practice Test



Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 

Males are more often affected by sex-linked traits than females because
a.
males are hemizygous for the X chromosome.
b.
male hormones such as testosterone often alter the effects of mutations on the X chromosome.
c.
female hormones such as estrogen often compensate for the effects of mutations on the X.
d.
X chromosomes in males generally have more mutations than X chromosomes in females.
e.
mutations on the Y chromosome often worsen the effects of X-linked mutations.
 

 2. 

The following is a map of four genes on a chromosome:

mc002-1.jpg
Figure 15.1

Between which two genes would you expect the highest frequency of recombination?
a.
A and W
b.
W and E
c.
E and G
d.
A and E
e.
A and G
 

 3. 

What is the reason that linked genes are inherited together?
a.
They are located close together on the same chromosome.
b.
The number of genes in a cell is greater than the number of chromosomes.
c.
Chromosomes are unbreakable.
d.
Alleles are paired together during meiosis.
e.
Genes align that way during metaphase I of meiosis.
 

 4. 

What is the source of the extra chromosome 21 in an individual with Down syndrome?
a.
Nondisjunction in the mother only
b.
Nondisjunction in the father only
c.
Duplication of the chromosome
d.
Nondisjunction or translocation in either parent
e.
It is impossible to detect with current technology
 

 5. 

A couple has a child with Down syndrome when the mother is 39 years old at the time of delivery. Which is the most probable cause?
a.
The woman inherited this tendency from her parents.
b.
One member of the couple carried a translocation.
c.
One member of the couple underwent nondisjunction in somatic cell production.
d.
One member of the couple underwent nondisjunction in gamete production.
 

 6. 

At which phase(s) is it preferable to obtain chromosomes to prepare a karyotype?
a.
Early prophase
b.
Late telophase
c.
Anaphase
d.
Late anaphase or early telophase
e.
Late prophase or metaphase
 

 7. 

For a couple of decades, biologists knew the nucleus contained DNA and proteins. The prevailing opinion was that the genetic material was proteins, and not DNA. The reason for this belief was that proteins are more complex than DNA. What was the basis of this thinking?
a.
Proteins have a greater variety of three-dimensional forms than does DNA.
b.
Proteins have two different levels of structural organization; DNA has four.
c.
Proteins are made of 40 amino acids and DNA is made of four nucleotides.
d.
Some viruses only transmit proteins.
e.
A and B are correct.
 

 8. 

For a science fair project, two students decided to repeat the Hershey and Chase experiment, with modifications. They decided to label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogens. Thus, labeling the nitrogens would provide a stronger signal than labeling the phosphates. Why won't this experiment work?
a.
There is no radioactive isotope of nitrogen.
b.
Radioactive nitrogen has a half-life of 100,000 years, and the material would be too dangerous for too long.
c.
Avery et al. have already concluded that this experiment showed inconclusive results.
d.
Although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons; therefore, they are more radioactive.
e.
Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.
 

 9. 

Chargaff's analysis of the relative base composition of DNA was significant because he was able to show that
a.
the relative proportion of each of the four bases differs within individuals of a species.
b.
the human genome is more complex than that of other species.
c.
the amount of A is always equivalent to T, and C to G.
d.
the amount of ribose is always equivalent to deoxyribose.
e.
transformation causes protein to be brought into the cell.
 

 10. 

What kind of chemical bond is found between paired bases of the DNA double helix?
a.
hydrogen
b.
ionic
c.
covalent
d.
sulfhydryl
e.
phosphate
 

 11. 

In an analysis of the nucleotide composition of DNA, which of the following will be found?
a.
A = C
b.
A = G and C = T
c.
A + C = G + T
d.
G + C = T + A
 

 12. 

What determines the nucleotide sequence of the newly synthesized strand during DNA replication?
a.
the particular DNA polymerase catalyzing the reaction
b.
the relative amounts of the four nucleoside triphosphates in the cell
c.
the nucleotide sequence of the template strand
d.
the primase used in the reaction
e.
the arrangement of histones in the sugar phosphate backbone
 

 13. 

At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork:
3' C C T A G G C T G C A A T C C 5'
An RNA primer is formed starting at the underlined T (T) of the template. Which of the following represents the primer sequence?
a.
5' G C C T A G G 3'
b.
3' G C C T A G G 5'
c.
5' A C G T T A G G 3'
d.
5' A C G U U A G G 3'
e.
5' G C C U A G G 3'
 

 14. 

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?
a.
synthesize RNA nucleotides to make a primer
b.
catalyze the lengthening of telomeres
c.
join Okazaki fragments together
d.
unwind the parental double helix
e.
stabilize the unwound parental DNA
 

 15. 

In his work with pneumonia-causing bacteria and mice, Griffith found that
a.
the protein coat from pathogenic cells was able to transform nonpathogenic cells.
b.
heat-killed pathogenic cells caused pneumonia.
c.
some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic.
d.
the polysaccharide coat of bacteria caused pneumonia.
e.
bacteriophages injected DNA into bacteria.
 



 
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