Question 1

Which of the following best describes the main difference between mitosis and meiosis in terms of genetic variation?

Accepted Answer

Meiosis produces genetically unique haploid cells due to crossing over and independent assortment, while mitosis produces genetically identical diploid cells.

Question 2

During which phase of the cell cycle does DNA replication occur?

Accepted Answer

S phase

Question 3

A mutation in a cell cycle kinase prevents phosphorylation of target proteins. What is the most likely consequence?

Accepted Answer

The cell cycle may halt at a checkpoint, preventing progression to the next phase.

Question 4

If a diploid cell with 6 chromosomes undergoes mitosis, how many chromosomes and DNA molecules will each daughter cell have immediately after cytokinesis?

Accepted Answer

6 chromosomes and 6 DNA molecules

Question 5

Which of the following events occurs during prophase I of meiosis but not during prophase of mitosis?

Accepted Answer

Pairing of homologous chromosomes and crossing over

Question 6

A cell is observed with chromosomes aligned at the metaphase plate, each consisting of two sister chromatids. Which phase is this cell in?

Accepted Answer

Metaphase

Question 7

Which of the following best explains why offspring from sexual reproduction are genetically different from their parents?

Accepted Answer

Crossing over and independent assortment during meiosis create new combinations of alleles.

Question 8

How is the number of chromosomes in a cell determined?

Accepted Answer

By counting the number of functional centromeres

Question 9

Which of the following is a direct consequence of a mutation that disables the spindle assembly checkpoint?

Accepted Answer

Chromosomes may not be properly segregated, leading to aneuploidy.

Question 10

During which stage of meiosis do homologous chromosomes separate?

Accepted Answer

Anaphase I

Question 11

Which of the following best describes the structure of chromatin in eukaryotic cells?

Accepted Answer

DNA is wrapped around nucleosomes composed of histone proteins.

Question 12

A geneticist observes a cell with 8 chromosomes and 16 DNA molecules during metaphase. What is the ploidy and what process is likely occurring?

Accepted Answer

Diploid cell in metaphase of mitosis

Question 13

Which of the following is NOT a feature of meiosis II?

Accepted Answer

Reduction of chromosome number by half

Question 14

Which checkpoint ensures that all chromosomes are properly attached to the spindle before anaphase begins?

Accepted Answer

Spindle assembly checkpoint (M checkpoint)

Question 15

In a human cell, how many chromosomes and DNA molecules are present during metaphase of mitosis?

Accepted Answer

$$46$$ chromosomes and $$92$$ DNA molecules

Question 16

Which process is responsible for the random distribution of maternal and paternal chromosomes into gametes?

Accepted Answer

Independent assortment during metaphase I

Question 17

Which of the following best explains why polar bodies do not undergo further division during oogenesis?

Accepted Answer

They do not receive enough cytoplasm to support further division.

Question 18

Which of the following is a correct sequence of events during mitosis?

Accepted Answer

Prophase → Metaphase → Anaphase → Telophase

Question 19

Which of the following statements about the consequences of mitosis is correct?

Accepted Answer

Mitosis produces two genetically identical diploid cells.

Question 20

What is the role of cohesin during cell division?

Accepted Answer

It holds sister chromatids together until anaphase.

Chromosomes and Cellular Reproduction: Foundations of Genetics

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