Major Exam 3

Question 1

Which of the following objects lacks a genome?

• nucleus
• chloroplast
• mitochondrion
• virus particle
• all of these choices have a genome

Answer 1

All of these choices have a genome

Question 2

One difference between eukaryotic and prokaryotic DNA packaging is:

• prokaryotic cells have different nucleotides that are smaller than eukaryotic cells
• Eukaryotic cells have fewer genes than prokaryotic cells
• DNA wraps around histones in eukaryotic packaging
• prokaryotic cells have smaller chromosomes and thus fit into the cell unaltered

Answer 2

DNA wraps around histones in eukaryotic packaging

Question 3

Virus genomes can be:

• single stranded RNA
• single stranded DNA
• double stranded DNA
• all of these answer choices are correct

Answer 3

All of these choices are correct

Question 4

________ mutations are important to the evolutionary process; most cancers result from ________ mutations.

• somatic; germ-line
• germ-line; somatic
• germ-line; heritable
• somatic; heritable
• point; germ-line

Answer 4

Germ-line; somatic

Question 5

In humans, the rate of point mutation tends to be greater in males than in females because:

• the testes are more exposed to the environment than the ovaries
• male meiosis is more sensitive to mutagens than female meiosis
• DNA repair in males I less efficient than that in females
• male germ-line cells undergo many more divisions than female germ-line cells

Answer 5

male germ-line cells undergo many more divisions than female germ-line cells

Question 6

In organisms with large genomes, inversions are more likely to be tolerated if the breakpoints occur in:

• coding DNA
• noncoding DNA
• open reading frames
• Reciprocal translocations

Answer 6

noncoding DNA

Question 7

Harmful mutations are often eliminated in a population because they:

• are fatal to the individual
• are repaired
• decrease survival and/or reproduction of the individual
• do not confer a benefit to the individual

Answer 7

decrease survival and/or reproduction of the individual

Question 8

An individual is homozygous for a gene if:

• the mother is homozygous for the gene
• the father is homozygous for the gene
• they developed from a sperm and an egg that carried the same allele
• they developed from a sperm and an egg that carried different alleles
• none of the other answer options are correct

Answer 8

they developed from a sperm and an egg that carried the same allele

Question 9

Most genetic variation in a population is:

• obvious
• beneficial
• harmful
• deleterious
• neutral

Answer 9

Neutral

Question 10

What is the probability that an individual is aa if his or her parents are both heterozygous for the trait?

• 1/4
• 1/2
• 3/4
• 1

Answer 10

1/4

Question 11

The F1 generation of a cross between two individuals, one that is homozygous dominant for a trait and the other is homozygous recessive for the trait, will yield progeny with the same phenotype.

• True
• False

Answer 11

True

Question 12

Segregation of alleles corresponds to the separation of:

• genes
• genotypes
• chromosomes
• phenotypes

Answer 12

Chromosomes

Question 13

Direct-to-consumer genetic tests:
(Choose all that apply)

• can be purchased directly by consumers
• may or may not be reliable
• are the best way to determine whether or not an individual carries an allele associated with a specific disease
• A and B only
• A and C only

Answer 13

A and B only

Question 14

The human X chromosome carries approximately 1000 genes. The Y chromosome contains only about 50 genes. How can males survive with only these 50 genes in the Y chromosome?

• the y is paired with a functional X chromosome, which has all the genes
• the genes in the X chromosome are not required for survival
• in males, the missing genes are found in autosomal chromosomes
• most of the 1000 genes in the X chromosome are only required for females

Answer 14

the y is paired with a functional X chromosome, which has all the genes

Question 15

In animals with Sex chromosomes, males inherit their X chromosome from their _____ and transmit it to their ____.

• mothers; daughters
• mothers; sons
• fathers; daughters
• fathers; sons
• mothers; sons and daughters

Answer 15

Mothers; daughters

Question 16

Y-linked traits are:

• never inherited by females
• never transmitted by females
• transmitted only by carrier females
• transmitted by affected fathers only to their sons
• never inherited or transmitted by females, and are transmitted by affected fathers only to their sons

Answer 16

never inherited or transmitted by females, and are transmitted by affected fathers only to their sons

Question 17

Analysis of mitochondrial DNA can answer interesting and important questions. For which of the following questions would analyzing mitochondrial DNA be futile?

▪I have poor muscle function, is there something wrong with my ability to make lots of ATP?
▪Are you my father?
▪Are you my long-lost brother?
▪From biological samplings at a crime scene, can we keep this person as our primary suspect?
▪Which is more closely related to the great white shark, the tiger shark or the hammerhead shark?

Answer 17

Are you my father?

Question 18

Which of the following are complex traits in humans?

• depression
• height
• autism
• B & C only
• A, B, & C.

Answer 18

A, B and C

Question 19

Ten individuals of two inbred strains of mice, A and B, are fed identical diets. When fed low sugar diets, all have normal blood sugar as adults. The same mice are then fed diets high in sugar. Mice from strain B develop diabetes, but mice from strain A do not. Diabetes in strain B mice results from:

• the interaction of their diet with their genotype.
• their genotypes, which are different from strain A mice.
• their diets, which are different from strain A mice.
• None of the above answer choices are correct.

Answer 19

the interaction of their diet with their genotype

Question 20

When heritability is 100%, the variation among individuals in the population is due to:

• genotype.
• phenotype.
• Both of these choices are correct.

Answer 20

genotype