Question 1

Which of the following best describes the primary difference between mitosis and meiosis in terms of chromosome number in the resulting cells?

Accepted Answer

Mitosis produces two diploid cells, while meiosis produces four haploid cells.

Question 2

During which phase of the cell cycle does DNA replication occur, and what is the result in terms of chromatid number?

Accepted Answer

DNA replication occurs during S phase, resulting in two chromatids per chromosome.

Question 3

A mutation in the gene encoding the protein separase would most directly affect which stage of mitosis?

Accepted Answer

Anaphase

Question 4

Which of the following equations correctly represents the change in DNA content per nucleus during the cell cycle, assuming a diploid organism with 2n chromosomes and C amount of DNA at $$G_1$$?

Accepted Answer

At $$G_1$$: $$2n, C$$; After S: $$2n, 2C$$; After mitosis: $$2n, C$$

Question 5

Which structure is responsible for the movement of chromosomes during mitosis and what is its main component?

Accepted Answer

The spindle apparatus, composed of microtubules

Question 6

A cell is observed to have chromosomes aligned at the metaphase plate, with spindle fibers attached to kinetochores. Which checkpoint must be passed before the cell can proceed to the next stage?

Accepted Answer

Metaphase checkpoint

Question 7

In a human cell, how many chromosomes and chromatids are present at the end of S phase?

Accepted Answer

46 chromosomes and 92 chromatids

Question 8

Which of the following events is unique to meiosis and not found in mitosis?

Accepted Answer

Crossing over between homologous chromosomes

Question 9

A male patient has a genetic disorder involving improper pairing of X and Y chromosomes during meiosis. Which region is most likely affected?

Accepted Answer

The pseudoautosomal regions (PARs)

Question 10

Which protein complex is responsible for holding sister chromatids together and is cleaved to allow their separation during anaphase?

Accepted Answer

Cohesin

Question 11

If a cell fails to pass the $$G_1$$ checkpoint, what is the most likely fate of the cell?

Accepted Answer

It will enter the $$G_0$$ phase and may undergo terminal differentiation.

Question 12

Which of the following best explains why gametes produced by meiosis are genetically unique?

Accepted Answer

Crossing over and independent assortment during meiosis

Question 13

A cell with genotype AaBb undergoes meiosis. According to Mendel's law of independent assortment, what is the expected ratio of gamete genotypes?

Accepted Answer

1:1:1:1 for AB, Ab, aB, ab

Question 14

During which stage of meiosis do homologous chromosomes separate, and what is the result for chromosome number?

Accepted Answer

Anaphase I; chromosome number is reduced by half

Question 15

Which of the following best describes the role of the contractile ring in animal cell cytokinesis?

Accepted Answer

It creates a cleavage furrow that pinches the cell into two daughter cells.

Question 16

A researcher observes a cell with four visible chromatids per homologous pair, recombination nodules, and chiasmata. Which stage of meiosis is this cell most likely in?

Accepted Answer

Pachytene

Question 17

Which of the following is a direct consequence of a mutation that prevents the formation of the synaptonemal complex during meiosis?

Accepted Answer

Failure of homologous chromosomes to pair and cross over

Question 18

Which of the following best explains the mechanical basis for Mendel’s law of segregation?

Accepted Answer

Separation of homologous chromosomes during meiosis I

Question 19

A cell is observed to have polar microtubules extending and the cell elongating, but chromosomes are already separated. Which phase is this cell most likely in?

Accepted Answer

Anaphase B

Cell Division and Chromosome Heredity: Mitosis and Meiosis

Study Guide - Practice Questions

Study Guide - Flashcards