Genetics - Cumulative Section Quizzes

What structure contains DNA?

Nucleus

In which part of the cell cycle does DNA synthesis occur?

S Phase

If two genes are close together on the same chromosome, then the traits affected by the two genes do not do what during meiosis?

Assort independently

Which of the following is the defining difference between prokaryotic and eukaryotic cells?

a

A eukaryotic cell lacks a nucleus.

b

A prokaryotic cell lacks a nucleus.

c

Eukaryotic cells do not have membrane-bound organelles.

d

Prokaryotic cells lack a cell wall.

b

A prokaryotic cell lacks a nucleus.

Meiosis allows...

a

the generation of genetic variation among offspring

b

the generation of new combinations of alleles on the same chromosome

c

the transmission of equivalent genetic information from generation to generation

d

the genetic contribution of two individual parents to each offspring

e

all of the above

e

all of the above

During meiosis I,...

a

sister chromatids separate

b

dyads split to form monads

c

crossing over takes place

d

an equational division takes place

e

centromeres divide

c

crossing over takes place

In mitosis, sister chromatids are separated during ______, while sister chromatids are separated in ______ of meiosis.

anaphase; anaphase II

If the green pea pod allele (G) is dominant to the yellow allele (g), a cross between two heterozygous plants would be expected to produce _____ plants.

3/4 green and 1/4 yellow

If a mouse has a dominant phenotype (P–), how would you determine if it is homozygous (PP) or heterozygous (Pp)?

Cross it to a mouse with the recessive trait.

Independent assortment occurs _____.

between any two genes on different chromosomes

What is the probability that two parents who are heterozygous for the recessive trait of albinism will have two albino offspring?

1/16

How many different types of gametes can be formed by the genotype AaBbCc?

8

In a plant species, if the B allele (blue flowers) and the b allele (white flowers) are incompletely dominant (Bb is light blue), what offspring ratio is expected in a cross between a blue-flowered plant and a white-flowered plant?

All light blue

If a mother has type A blood and her son has type O blood, what are the possible blood types of her son’s father?

Type A, B, or O

A cross between two short-tailed mice results in offspring in the ratio of 2/3 short-tailed and 1/3long-tailed. The best explanation for this result is that _____.

there is a recessive lethal allele

Duchenne muscular dystrophy is caused by a recessive X-linked allele. A man with this disorder _____.

must have inherited it from his mother

In sheep, assume the presence of horns is due to a single gene. Both males and females may have horns, but horns are present in heterozygous males, though not heterozygous females. This is a good example of _____.

sex-influenced inheritance

In chickens, the hens are the heterogametic sex. Which sex has the Y chromosome?

Neither male nor female

A human individual with 45 chromosomes has a _____.

monosomy

In humans, the genetic basis for determining the sex "male" is accomplished by the presence of _____.

a portion of the Y chromosome

Klinefelter syndrome in humans, which leads to underdeveloped testes and sterility, is caused by which chromosomal condition?

47, XXY

For an individual with the XXY chromosomal composition, the expected number of Barr bodies in interphase cells is _____.

one

Can a person have 45 chromosomes and be phenotypically normal?

Yes, if the person is a translocation carrier.

Fragile sites _____.

are often associated with regions of short tandem DNA sequence repeats

Autotriploids _____.

a

may result from the fertilization of a haploid gamete with an abnormal diploid gamete

b

may result from the fertilization of an egg by two haploid sperm

c

may result from the crossing of a diploid with a tetraploid

d

have three chromosome sets that are identical in terms of number and content

e

all of the above

all of the above

Linkage affects expected ratios because it violates which of Mendel’s postulates?

Genes independently assort in meiosis.

The condition that exists when an organism gains or loses one or more chromosomes but not a complete haploid set is known as _____.

aneuploidy

Assume that a cross is made between AaBb and aabb plants and that all the offspring are either AaBb or aabb. These results are consistent with _____.

complete linkage

The phenomenon in which one crossover decreases the likelihood of crossovers in nearby regions is called _____.

positive interference

Assume that a cross is made between AaBb and aabb plants and that the offspring fall into approximately equal numbers of the following groups: AaBb, Aabb, aaBb, aabb. These results are consistent with _____.

independent assortment

Two genes that are 60 map units apart are expected to show _____.

independent assortment

An E. coli trp– auxotroph can grow on _____.

a

minimal medium

b

minimal medium plus amino acids

c

complete medium

d

both B and C

e

A, B, and C

both B and C

When strains A and B (auxotrophic for different compounds) are mixed together, they readily form prototrophs; however, in the Davis U tube, they do not. These cells must be undergoing ____.

conjugation

In an Hfr × F– mating, if the order of transfer of loci is leu – azi – ton – lac, one can conclude that _____.

leu is adjacent to the point of origin

Name the general category into which double-stranded circular extrachromosomal DNA elements such as F factors, ColE1, and R would fall.

plasmid

Name two forms of recombination in bacteria.

conjugation and transduction

Which of the following is not consistent with Erwin Chargaff’s findings?

(C + G) = (A + T)

The zebrafish is found to have ~19% guanine in its DNA. How much adenine would you expect?

31%

Which of the following is not included in the Watson–Crick model of DNA structure?

The strands run parallel.

In a polynucleotide, the individual nucleotides are covalently linked together by bonds between the _____.

sugars and phosphate

Which enzyme unwinds the DNA helix so that replication can occur?

helicase

All known bacterial DNA polymerases _____.

have 5′ to 3′ polymerization activity

Is there any role for an RNA polymerase in DNA replication?

Yes, to generate primers

Which terms accurately reflect the nature of replication of the chromosome in E. coli?

bidirectional and fixed point of initiation

Telomerase _____.

a

contains its own RNA template

b

is a reverse transcriptase

c

extends one strand of the telomere

d

is responsible for helping to maintain chromosome size

e

All of the above are true.

All of the above are true

Which of the following terms accurately describes the replication of DNA in vivo? 

semiconservative

DNA polymerase I is thought to add nucleotides _____.

in the place of the primer RNA after it is removed

The basic structure of a nucleotide includes _____.

base, sugar, and phosphate

Regarding the structure of DNA, the covalently arranged combination of a deoxyribose and a nitrogenous base would be called a(n) _____.

nucleoside