Deck 6: The Cellular Basis for Mendelian Genetics

Question 1

Which phase of the cell cycle has two copies of the genome in the cell for the entire phase?

A) G1
B) S
C) G2
D) M

Answer 1

G2

Question 2

Which of the following phases are in mitosis? Please select all that apply.

A) Metaphase
B) Interphase
C) Anaphase
D) Telophase
E) Prophase

Answer 2

Metaphase
Anaphase
Telophase
Prophase

Question 3

Match the missing words in the following phrase. Microtubules consist of alpha-tubulin and beta-tubulin. Microtubules are polar, with alpha-tubulin at the [A] end and beta-tubulin at the [B] end. Microtubules attach to the [C] and originate from the [D].

Answer 3

a. A = minus
b. B = plus
c. C = centromere
d. D = centrosome

Question 4

Put the following events in order of occurrence, beginning with the start of G1 phase.

-DNA replication

A) 1
B) 2
C) 3
D) 4

Question 5

Put the following events in order of occurrence, beginning with the start of G1 phase.

-Centrosome separation

A) 1
B) 2
C) 3
D) 4

Question 6

Put the following events in order of occurrence, beginning with the start of G1 phase.

-Aster formation

A) 1
B) 2
C) 3
D) 4

Question 7

Put the following events in order of occurrence, beginning with the start of G1 phase.

-Chromosome separation

A) 1
B) 2
C) 3
D) 4

Question 8

The kinetochore consists of proteins attached to the centromere of the chromosome.

Question 9

Chromosomes align at the metaphase plate before separating at anaphase. Which of the following factors keep chromosomes together at metaphase? Please select all that apply.

A) separase
B) securin
C) cohesin

Question 10

The role of checkpoints in the cell cycle is to accelerate the transitions between different phases of the cycle.

Question 11

Which of the following statements about meiosis and mitosis are true? Please select all that apply.

A) Meiosis involves two rounds of DNA replication
B) Meiosis involves four rounds of chromosome/chromatid separation
C) Mitosis involves one round of DNA replication
D) Mitosis involves one round of chromosome/chromatid separation

Question 12

Match the missing words in the following phrase. [A] separate during meiosis I and [B] separate during meiosis II. Mitosis is more similar to [C] than to [D].

Question 13

What is chromosome pairing?

A) Recognition and coming together of homologous chromosomes
B) Replication and joining of the chromatids in each chromosome
C) Localization of chromosomes at the nuclear envelope
D) Crossing over between chromosomes

Question 14

Which of the statements about the synaptonemal complex (SC) are false? Please select all that apply.

A) The synaptonemal complex forms between chromosomes in meiosis and mitosis
B) Lateral element proteins of the SC are evolutionarily conserved
C) The width of the SC differs between organisms
D) Central element proteins of the SC are evolutionarily conserved
E) The SC is not found in all eukaryotes

Question 15

Double-strand breaks (DSB) are needed for crossing-over to occur in meiosis. In a pair of homologous chromosomes, how many chromatids require a DSB in order for crossing over to occur?

A) 1
B) 2
C) 3
D) 4

Question 16

Non-disjunction is when chromosomes fail to separate properly. What factor usually leads to non-disjunction?

A) Failure of chromosomes to cross-over
B) Uncontrolled DNA replication
C) Apoptosis
D) SPO11 activity

Question 17

Which of the following statements about crossovers are true? Please select all that apply.

A) Crossover number is consistent in a given organism
B) Crossover location is consistent in a given organism
C) Successful meiosis is not dependent on crossovers
D) Crossover number and location is regulated

Question 18

The two kinetochores on one homologue face in opposite directions in meiosis I and face in the same direction in meiosis II.

Question 19

Which part of meiosis explains Mendel's Law of Segregation at the chromosome level?

A) Separation of homologues at meiosis II
B) Separation of homologues at meiosis I
C) Separation of sister chromatids at meiosis II
D) Separation of sister chromatids at meiosis I

Question 20

What is a tetrad?

A) The four haploid products of meiosis
B) The four homologous chromosomes at metaphase
C) The four kinetochores of paired homologous chromosomes
D) The four nuclei that fuse during meiosis

Question 21

Which of the following differ between oogenesis and spermatogenesis in humans? Please select all that apply.

A) The fate of the four products of meiosis
B) The number of chromosomes in the gametes
C) The number of meiotic crossovers
D) The duration of meiosis

Question 22

Match the missing words in the following phrase. Normal meiosis results in each gamete receiving a normal number of chromosomes - resulting offspring are [A]. When chromosomes or chromatids fail to separate properly during meiosis, gametes can receive one extra copy of a chromosome - this is [B] - or be missing one copy - this is [C]. Any resulting organism is then [D].

Question 23

Which of the statements about non-disjunction are true? Please select all that apply.

A) Non-disjunction at meiosis II has a more severe impact than at meiosis I
B) Non-disjunction at meiosis II leads to two normal gametes and two abnormal gametes.
C) Non-disjunction at meiosis II leads to three abnormal gametes and one normal gamete.
D) Non-disjunction at meiosis I leads to four abnormal gametes.
E) Non-disjunction at meiosis I leads to three normal gametes and one abnormal gamete.

Question 24

Most cases of trisomy 21 in humans occur as a result of:

A) Translocation of sections of chromosome 21 to another chromosome
B) Excess crossovers
C) Crossovers occurring at the end of the chromosome
D) No crossovers occurring

Question 25

Mitosis is more evolutionarily ancestral than meiosis.

Question 26

Fill in the missing words in the following phrase. [A] of the DNA sequence of a gene gives rise to different alleles. A diploid organism can carry two different alleles. After DNA is [B], [C] have the same allele and [D] carry different alleles. Alleles are [E] during meiosis, giving rise to Mendelian patterns of [F] and possible differences in phenotype.

Question 27

Put the steps of meiotic recombination in the correct order

-DNA double-strand break

A) Step 1
B) Step 2
C) Step 3
D) Step 4

Question 28

Put the steps of meiotic recombination in the correct order

-strand invasion

A) Step 1
B) Step 2
C) Step 3
D) Step 4

Question 29

Put the steps of meiotic recombination in the correct order

-DNA synthesis

A) Step 1
B) Step 2
C) Step 3
D) Step 4

Question 30

Put the steps of meiotic recombination in the correct order

-Holliday junction resolution

A) Step 1
B) Step 2
C) Step 3
D) Step 4

Question 31

Which of the statements about autopolyploids and allopolyploids are true? Please select all that apply.

A) Allopolyploids are likely to produce viable offspring
B) Autopolyploids are unlikely to produce viable offspring
C) Allopolyploids and autopolyploids always have different numbers of chromosomes
D) Allopolyploids contain multiple copies of a single genome
E) Autopolyploids contain copies of different genomes.