Question 1

Which of the following statements best distinguishes prokaryotic cells from eukaryotic cells?

Accepted Answer

Eukaryotic cells have chromosomes associated with histone proteins, whereas prokaryotic cells lack histone complexes.

Question 2

A duplicated chromosome consists of:

Accepted Answer

Two sister chromatids joined at the centromere.

Question 3

During meiosis I, homologous chromosomes pair up and exchange genetic material. What is the name of the structure formed by this pairing, and what is the process called?

Accepted Answer

Bivalent; synapsis

Question 4

If a human cell has a diploid number $$2n = 46$$, how many chromosomes and DNA molecules are present in a cell during metaphase of mitosis?

Accepted Answer

46 chromosomes and 92 DNA molecules

Question 5

Which of the following best describes the chromosomal basis of sex in humans?

Accepted Answer

Females have two X chromosomes; males have one X and one Y chromosome.

Question 6

Which stage of the cell cycle is primarily responsible for DNA replication?

Accepted Answer

S phase

Question 7

During which phase of mitosis do chromosomes align at the cell's equator?

Accepted Answer

Metaphase

Question 8

Which type of cells undergo mitosis for nuclear division?

Accepted Answer

Somatic cells

Question 9

Crossing over during Prophase I of meiosis increases genetic diversity. Which structure is directly involved in this process?

Accepted Answer

Chiasma

Question 10

Nondisjunction during meiosis can lead to abnormal gametes. Which scenario best describes nondisjunction in meiosis II?

Accepted Answer

Sister chromatids fail to separate, resulting in gametes with either two copies or no copies of a chromosome.

Question 11

Which of the following is NOT a source of genetic variation in sexual reproduction?

Accepted Answer

Replication of DNA during S phase

Question 12

Compare mitosis and meiosis: Which statement is correct regarding the number of cell divisions and daughter cells produced?

Accepted Answer

Mitosis involves one cell division producing two daughter cells; meiosis involves two cell divisions producing four daughter cells.

Question 13

If an organism has a diploid number $$2n = 8$$, how many chromosomes are aligned at the metaphase plate during metaphase I of meiosis?

Accepted Answer

8 chromosomes (as homologous pairs)

Question 14

Which of the following best describes the difference between male and female gametogenesis?

Accepted Answer

Male gametogenesis produces four functional sperm cells per division, while female gametogenesis produces one functional egg and three polar bodies.

Question 15

Why are chromosomal abnormalities more likely to occur during oogenesis than spermatogenesis?

Accepted Answer

Oogenesis involves prolonged arrest during meiosis, increasing the risk of errors in chromosome segregation.

Question 16

Older paternal age is correlated with which type of genetic mutation?

Accepted Answer

Increased base substitutions due to more rounds of DNA replication in spermatogenesis.

Question 17

Which term describes a pair of chromosomes that are similar in size, shape, and genetic content, one inherited from each parent?

Accepted Answer

Homologous chromosomes

Question 18

A cell with a haploid number $$n = 23$$ undergoes meiosis. How many chromosomes will each gamete contain after meiosis is complete?

Accepted Answer

23 chromosomes

Question 19

Which event occurs during synapsis in meiosis?

Accepted Answer

Homologous chromosomes pair up and align closely, allowing crossing over.

Question 20

Which of the following best explains why independent assortment during meiosis is important for genetic variation?

Accepted Answer

It allows different combinations of maternal and paternal chromosomes to be distributed to gametes.

Genetics Study Guide: Chromosomes and Cellular Reproduction

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