Question 1

Which of the following best describes homologous chromosomes in a diploid organism?

Accepted Answer

They carry genes for the same inherited characteristics but may have different alleles.

Question 2

During which phase of the cell cycle is DNA synthesized?

Accepted Answer

S phase

Question 3

A mutation in a yeast cell affects a kinase involved in cell cycle regulation. What is the most likely consequence?

Accepted Answer

The cell may fail to properly regulate progression through the cell cycle checkpoints.

Question 4

Which of the following equations correctly represents the chromosome number in a diploid organism?

Accepted Answer

$$2n$$

Question 5

What is the primary function of the centromere during mitosis?

Accepted Answer

To hold sister chromatids together and serve as the attachment site for spindle fibers

Question 6

Which checkpoint in the cell cycle ensures that DNA is undamaged and fully replicated before mitosis begins?

Accepted Answer

G2/M checkpoint

Question 7

During which stage of mitosis do sister chromatids separate and move toward opposite poles?

Accepted Answer

Anaphase

Question 8

A human cell in G1 phase has 46 chromosomes. After DNA replication in S phase, how many chromatids will be present?

Accepted Answer

92

Question 9

Which of the following events is unique to meiosis and does NOT occur during mitosis?

Accepted Answer

Pairing of homologous chromosomes and crossing over

Question 10

If nondisjunction occurs during Anaphase I of meiosis, what is the most likely outcome?

Accepted Answer

Some gametes will have an extra chromosome, and some will be missing one.

Question 11

Which formula represents the number of possible chromosome combinations in gametes due to independent assortment, where $$n is $$the haploid number?

Accepted Answer

$$2^n$$

Question 12

In oogenesis, meiosis is arrested at which stage until ovulation occurs?

Accepted Answer

Metaphase II

Question 13

Which of the following best explains why sister chromatids are considered identical?

Accepted Answer

They are the result of DNA replication and contain the same genetic information.

Question 14

A cell is observed to have chromosomes aligned at the metaphase plate, with spindle fibers attached to centromeres. Which stage is this?

Accepted Answer

Metaphase

Question 15

Which protein complex is responsible for holding sister chromatids together until anaphase?

Accepted Answer

Cohesin

Question 16

During meiosis, crossing over occurs in which substage of prophase I?

Accepted Answer

Pachytene

Question 17

Which of the following is true regarding the products of meiosis in humans?

Accepted Answer

Each product is haploid and genetically unique.

Question 18

A cell fails to pass the M checkpoint during the cell cycle. What is the most likely immediate consequence?

Accepted Answer

The cell will not proceed to anaphase until all chromosomes are properly attached to spindle fibers.

Question 19

Which of the following best describes the difference between mitosis and meiosis?

Accepted Answer

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

Question 20

Which of the following is a real-world consequence of a defect in cell cycle regulation?

Accepted Answer

Uncontrolled cell division leading to cancer

Chromosome Biology, Mitosis, and Meiosis: Study Notes

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