Bio Chapter 11: Study Questions Flashcards
Comparing somatic cells and gametes, somatic cells are
a. diploid with half the number of chromosomes.
b. haploid with half the number of chromosomes.
c. diploid with twice the number of chromosomes.
d. haploid with twice the number of chromosome
c. diploid with twice the number of chromosomes.
In the life cycle of most animals,
a. there is an alternation between diploid and haploid
chromosome numbers.
b. gametes are produced by meiosis.
c. the haploid stage is unicellular.
d. All of the above
d. All of the above
Egg and sperm have half the number of chromosomes as
somatic cells from the same organism. Why?
a. Once a gamete is formed, half the chromosomes
disintegrate.
b. During gamete formation, DNA replicates once, but cell
division occurs twice.
c. When gametes are produced by mitosis, DNA replication
does not occur during interphase.
d. Only half of the DNA is replicated during the meiotic cell
cycle.
b. During gamete formation, DNA replicates once, but cell
division occurs twice.
Synapsis occurs during
a. mitosis.
b. meiosis I.
c. meiosis II.
d. Both b and c
b. meiosis I.
The synaptonemal complex
a. connects homologous chromosomes at the beginning of
meiosis.
b. catalyzes crossing over.
c. remains intact until the end of meiosis II.
d. is unique to animal cells
connects homologous chromosomes at the beginning of
meiosis
Chiasmata form
a. between homologous chromosomes.
b. sister chromatids.
c. between replicated copies of the same chromosomes.
d. sex chromosomes but not autosomes
between homologous chromosomes.
Which of the following is NOT true of crossing over?
a. It occurs during prophase I.
b. It occurs during prophase II.
c. It occurs between homologues.
d. Exchange of DNA occurs at the points of crossing over
Exchange of DNA occurs at the points of crossing over
At metaphase I, the kinetochores of sister chromatids are
a. attached to microtubules from the same pole.
b. attached to microtubules from opposite poles.
c. held together with cohesin proteins.
d. not attached to any microtubules.
attached to microtubules from the same pole
During anaphase I,
a. sister chromatids separate and move to the poles.
b. homologous chromosomes move to opposite poles.
c. homologous chromosomes align at the middle of the cell.
d. all chromosomes align independently at the cell’s middle
homologous chromosomes move to opposite poles.
Mutations that affect DNA repair often also affect the accuracy
of meiosis. This is because
a. the proteins involved in the repair of double-strand breaks
are also involved in crossing over.
b. the proteins involved in DNA repair are also involved in
sister chromatid cohesion
c. DNA repair only occurs on condensed chromosomes such
as those found in meiosis.
d. cohesin proteins are also necessary for DNA repair.
the proteins involved in the repair of double-strand breaks
are also involved in crossing over
You measure the amount of DNA in a diploid cell in the G1
phase of the cell cycle. The cell completes meiosis I and you
measure the amount of DNA in one of the daughter cells. The
amount of DNA in the daughter cell
a. is double that of the G1 cell.
b. equals that of the G1 cell.
c. is one-half that of the G1 cell.
d. is one-quarter that of the G1 cel
is double that of the G1 cell.
Crossing over
a. seems to be important for correct disjunction.
b. occurs while homologous chromosomes are paired.
c. likely first evolved as a mechanism to repair double stranded DNA breaks.
d. All of the above
occurs while homologous chromosomes are paired
Structurally, meiotic cohesins have different components than
mitotic cohesins. This leads to which functional difference?
a. During metaphase I, the sister kinetochores become
attached to the same pole.
b. Centromeres remain attached during anaphase I of meiosis.
c. Centromeres remain attached through both divisions.
d. Centromeric cohesins are destroyed at anaphase I, and
cohesins along the arms are destroyed at anaphase II
Centromeres remain attached during anaphase I of meiosis
How are meiosis II and mitosis similar?
a. DNA replicates before nuclear division occurs.
b. Sister chromatids separate.
c. Diploid daughter cells are produced.
d. The chromosome number is halved.
Sister chromatids separate
Anaphase I comes about because of
a. release of sister chromatid cohesion along the chromosome
arms.
b. attachment of centromeres to microtubules originating
from opposite poles.
c. destruction of cohesin at the centromeres.
d. release of sister chromatid cohesion at the centromere
destruction of cohesin at the centromeres.
