Ch 2 Genetics Flashcards
Which of the follow could occur if a cell cycle checkpoint was missed?
Question 1 Answer
a.
An unreplicated chromosome could be put through mitosis.
b.
DNA would mutate during G2.
c.
The cell cycle would be arrested until the error could be corrected.
d.
The spindle apparatus would not form.
e.
Cohesin could not function correctly.
An unreplicated chromosome could be put through mitosis.
When cells withdraw from the continuous cell cycle and enter a “quiescent” phase, they are said to be in what stage?
Question 2 Answer
a.
G1
b.
G2
c.
G0
d.
M
e.
S
G0
In an organism with 60 chromosomes, how many bivalents would be expected to form during meiosis?
Question 3 Answer
a.
15
b.
30
c.
60
d.
120
e.
240
30
After meiosis II, ________ would be formed.
Question 4 Answer
a.
dyads
b.
tetrads
c.
monads
d.
synapsis
e.
chiasma
monads
The diploid chromosome number of an organism is usually represented as 2n. Humans have a diploid chromosome number of 46. What would be the expected haploid chromosome number in a human?
Question 5 Answer
a.
92
b.
16
c.
12
d.
24
e.
23
23
Which of the following is true about sex-determining chromosomes?
Question 6 Answer
a.
They are independent during meiosis.
b.
They do not participate in meiosis.
c.
They act like homologous chromosomes during meiosis so each gamete will get one sex chromosome.
d.
They have the same gene configuration and same loci.
e.
They are always metacentric.
They act like homologous chromosomes during meiosis so each gamete will get one sex chromosome.
A G1 somatic cell nucleus in a female diploid Myrmecia pilosula (bulldog ant) contains 2 picograms of DNA. How much DNA would be expected in a metaphase I cell of a female?
Question 7 Answer
a.
16 picograms
b.
32 picograms
c.
8 picograms
d.
4 picograms
e.
Not enough information is provided to answer the question.
4 picograms
Which chromosome has a telomere but the p arm is much shorter than the q arm?
Question 8 Answer
a.
metacentric
b.
submetacentric
c.
acrocentric
d.
telocentric
e.
sex chromosome
acrocentric
The house fly, Musca domestica, has a haploid chromosome number of 6. How many chromatids should be present in a diploid, somatic, metaphase cell?
Question 9 Answer
a.
3
b.
6
c.
12
d.
18
e.
24
24
List, in order of appearance, all the cell types expected to be formed during oogenesis.
Question 10 Answer
a.
primary oocyte, secondary oocyte and first polar body, oogonium, second polar body and ootid
b.
oogonium, primary oocyte, secondary oocyte and first polar body, ootid and second polar body
c.
primary oocyte, secondary oocyte and first polar body, ootid, second polar body, oogonium
d.
primary oocyte, secondary oocyte and first polar body, second polar body, ootid, oogonium
e.
oogonium, primary oocyte, second polar body and ootid, secondary oocyte and first polar body
oogonium, primary oocyte, secondary oocyte and first polar body, ootid and second polar body
If a typical somatic cell has 64 chromosomes, how many chromosomes are expected in each gamete of that organism?
Question 11 Answer
a.
8
b.
16
c.
32
d.
64
e.
128
32
In plants, which stage is haploid?
Question 12 Answer
a.
gametophyte
b.
sporophyte
c.
polar body
d.
spermatozoa
e.
germ cell
gametophyte
Which of the following are the areas where chromatids intertwine during meiosis?
Question 13 Answer
a.
synapsis
b.
chiasma
c.
tetrad
d.
bivalent
e.
nondisjunction
chiasma
During interphase of the cell cycle, ________.
Question 14 Answer
a.
DNA recombines
b.
sister chromatids move to opposite poles
c.
the nuclear membrane disappears
d.
RNA replicates
e.
DNA content essentially doubles
DNA content essentially doubles
Which of the following is diploid?
Question 15 Answer
a.
egg
b.
sperm
c.
zygote
d.
megaspore
e.
gametophyte
zygote
In a healthy female, how many secondary oocytes would be expected to form from 100 primary oocytes? How many first polar bodies would be expected from 100 primary oocytes?
Question 16 Answer
a.
200; 50
b.
100; 50
c.
200; 300
d.
100; 100
e.
50; 50
100; 100
Which if the following is not a source of genetic variation in meiosis?
Question 17 Answer
a.
crossing over
b.
law of independent assortment
c.
the random lining up of chromosomes on the metaphase plate
d.
tetrad formation
e.
polar body formation
polar body formation
What significant genetic function occurs in the S phase of the cell cycle?
Question 18 Answer
a.
cytokinesis
b.
karyokinesis
c.
DNA synthesis
d.
chromosome condensation
e.
centromere division
DNA synthesis
In which stage of the cell cycle is G0 located?
Question 19 Answer
a.
G1
b.
S
c.
G2
d.
M
e.
anaphase
G1
You have identified a mutant in human cells that when shifted to 37°C, the microfilaments depolymerize (fall apart). Which of the following would be true about this mutant at 37°C?
Question 20 Answer
a.
The mitochondria would no longer work.
b.
The sister chromatids would no longer be attached to each other.
c.
The cells would no longer be able to produce ATP.
d.
The cells would change shape.
e.
The endoplasmic reticulum could still import polypeptides but could no longer synthesize lipids.
The cells would change shape.
Which part of interphase does DNA duplication take place?
Question 21 Answer
a.
G1
b.
G2
c.
S
d.
G0
e.
M
S
Normal diploid somatic (body) cells of the mosquito Culex pipiens contain six chromosomes. Assuming that all nuclear DNA is restricted to chromosomes and that the amount of nuclear DNA essentially doubles during the S phase of interphase, how much nuclear DNA would be present in metaphase I of mitosis? Note: Assume that the G1 nucleus of a mosquito cell contains 3.0 × 10-12 grams of DNA.
Question 22 Answer
a.
3.0 × 10−12 g
b.
6.0 × 10−12 g
c.
1.5 × 10−12 g
d.
0.75 × 10−12 g
e.
12 × 10−12 g
6.0 × 10−12 g
Which of the following is true about the second meiotic division?
Question 23 Answer
a.
Sister chromatids are pulling apart.
b.
Homologous chromosomes are pulling apart.
c.
Nondisjunction would lead to extra bivalents forming.
d.
Synapsis occurring in the second meiotic division.
e.
The products are four identical gametes.
Sister chromatids are pulling apart.
Name two cellular organelles, each containing genetic material, which are involved in either photosynthesis or respiration.
Question 24 Answer
a.
rough and smooth endoplasmic reticula
b.
chloroplast and endoplasmic reticulum
c.
peroxisomes and mitochondria
d.
lysosome and chloroplast
e.
chloroplasts and mitochondria
chloroplasts and mitochondria
List, in order of appearance, all the cell types expected to be formed during spermatogenesis.
Question 25 Answer
a.
spermatogonia, primary spermatocyte, secondary spermatocyte, spermatid, spermatozoa
b.
primary spermatocyte, secondary spermatocyte, spermatozoa, spermatid, spermatogonia
c.
spermatozoa, spermatid, spermatogonia , primary spermatocyte, secondary spermatocyte
d.
spermatogonia, spermatozoa, spermatid, primary spermatocyte, secondary spermatocyte
e.
primary spermatocyte, secondary spermatocyte, spermatid, spermatozoa, spermatogonia
spermatogonia, primary spermatocyte, secondary spermatocyte, spermatid, spermatozoa
Living organisms are categorized into two major groups based on the presence or absence of a nucleus. What group is defined by the presence of a nucleus?
Question 26 Answer
a.
eukaryotic organism
b.
virus
c.
bacterium
d.
prokaryotic organism
e.
mitochondrial organism
eukaryotic organism
A typical G1 nucleus is 2n and contains 2C (two complements) of DNA. Which of the following is true?
Question 27 Answer
a.
A prophase cell is 4n and contains 4C of DNA.
b.
A cell in prophase is 2n and contains 2n of DNA.
c.
A cell in prophase is 2n and contains 4C of DNA.
d.
A cell in metaphase is 2n and contains 2C of DNA.
e.
A cell in G2 is 4n and contains 2C of DNA.
A cell in prophase is 2n and contains 4C of DNA.
The centromere of a chromosome separates during ________.
Question 28 Answer
a.
interphase
b.
prometaphase
c.
prophase
d.
anaphase
e.
telophase
anaphase
The meiotic cell cycle involves ________ number of cell division(s) and ________ number of DNA replication(s).
Question 29 Answer
a.
one; one
b.
one; two
c.
two; one
d.
two; two
e.
two; zero
two; one
The stage at which “sister chromatids go to opposite poles” immediately follows which of the stages listed below?
Question 31 Answer
a.
mitotic metaphase
b.
metaphase of meiosis I
c.
metaphase of meiosis II
d.
A and B
e.
A and C
A and C
In a healthy male, how many sperm cells would be expected to be formed from (a) 400 primary spermatocytes? (b) 400 secondary spermatocytes?
Question 32 Answer
a.
(a) 800; (b) 800
b.
(a) 1600; (b) 1600
c.
(a) 1600; (b) 800
d.
(a) 400; (b) 400
e.
(a) 100; (b) 800
(a) 1600; (b) 800
What is the outcome of synapsis, a significant event in meiosis?
Question 33 Answer
a.
side-by-side alignment of nonhomologous chromosomes
b.
dyad formation
c.
monad movement to opposite poles
d.
side-by-side alignment of homologous chromosomes
e.
chiasma segregation
side-by-side alignment of homologous chromosomes
How many haploid sets of chromosomes are present in a diploid individual cell with a chromosome number of 32?
Question 34 Answer
a.
2
b.
1
c.
8
d.
16
e.
32
2
A bivalent at prophase I contains ________ chromatids.
Question 35 Answer
a.
one
b.
two
c.
three
d.
four
e.
eight
four
During meiosis, chromosome number reduction takes place in ________.
Question 36 Answer
a.
anaphase II
b.
anaphase I
c.
metaphase I
d.
prophase I
e.
telophase II
anaphase I
If a typical G1 nucleus contains 2C (two complements) of DNA, a gamete that is haploid (n) contains ________ of DNA.
Question 38 Answer
a.
1C
b.
0.5C
c.
2C
d.
3C
e.
4C
1C
The nucleolus organizer region (NOR) is responsible for production of what type of cell structure?
Question 37 Answer
a.
nucleolus
b.
ribosome
c.
chromatids
d.
mitochondria
e.
endoplasmic reticulum
ribosome
