Question 1

Which of the following best describes the three key tenets of the cell theory?

Accepted Answer

All living things are made of cells; cells are the basic unit of structure and function; all cells arise from pre-existing cells.

Question 2

Which of the following correctly matches the cell cycle phases with their main events?

Accepted Answer

Interphase: cell growth and DNA replication; M phase: mitosis and cytokinesis.

Question 3

A human somatic cell contains 46 chromosomes. After DNA replication but before mitosis, how many chromatids are present in the cell?

Accepted Answer

$$92$$

Question 4

Which of the following best explains why crossing over during meiosis is important for evolution?

Accepted Answer

It increases genetic variation among offspring, providing material for natural selection.

Question 5

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

Accepted Answer

Anaphase

Question 6

Which of the following is a key difference between mitosis and meiosis?

Accepted Answer

Mitosis produces two genetically identical diploid cells, while meiosis produces four genetically unique haploid cells.

Question 7

A cell with a diploid number of $$2n = 8$$ undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

$$4$$

Question 8

Which of the following best describes the function of a kinetochore during cell division?

Accepted Answer

It attaches chromosomes to spindle fibers, allowing their movement during mitosis and meiosis.

Question 9

Which process is responsible for the formation of gametes in animals?

Accepted Answer

Meiosis

Question 10

If a mutation occurs in a gene regulating the cell cycle, which of the following is a possible consequence?

Accepted Answer

Uncontrolled cell division leading to cancer

Question 11

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

Accepted Answer

Homologous chromosomes pair and crossing over occurs.

Question 12

Which of the following best explains why sexual reproduction leads to greater genetic diversity than asexual reproduction?

Accepted Answer

It combines genetic material from two parents and involves processes like crossing over and independent assortment.

Question 13

A scientist observes a cell with chromosomes aligned at the center of the cell. Which phase is the cell most likely in?

Accepted Answer

Metaphase

Question 14

Which of the following is NOT a function of mitosis in multicellular organisms?

Accepted Answer

Production of gametes

Question 15

Which of the following best describes the ploidy of human gametes?

Accepted Answer

Haploid ($$n)$$

Question 16

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

Accepted Answer

S phase

Question 17

Which of the following is a result of nondisjunction during meiosis?

Accepted Answer

Gametes with abnormal numbers of chromosomes, such as in Down syndrome.

Question 18

Which of the following best describes the difference between homologous chromosomes and sister chromatids?

Accepted Answer

Homologous chromosomes are pairs from each parent; sister chromatids are identical copies formed by DNA replication.

Question 19

Which of the following processes increases genetic variation during meiosis?

Accepted Answer

Independent assortment of chromosomes

Question 20

A patient is diagnosed with chronic lymphocytic leukemia (CLL). Which of the following best describes the cellular basis of this disease?

Accepted Answer

Uncontrolled proliferation of abnormal lymphocytes due to dysregulation of the cell cycle.

Cell Cycle, Mitosis, and Meiosis: Review and Study Guide 7

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