Question 1

Which of the following best describes the process of binary fission in prokaryotes?

Accepted Answer

Binary fission is an asexual process where a single cell duplicates its chromosome and divides into two genetically identical daughter cells.

Question 2

During which phase of the eukaryotic cell cycle does DNA synthesis occur?

Accepted Answer

S phase

Question 3

A researcher treats cells with a chemical that prevents DNA synthesis from starting. In which part of the cell cycle would these cells be trapped?

Accepted Answer

G1 phase

Question 4

Which of the following statements about mitosis is correct?

Accepted Answer

Mitosis results in two daughter cells, each with a complete and identical set of chromosomes.

Question 5

How does cytokinesis differ between animal and plant cells?

Accepted Answer

Animal cells form a cleavage furrow, while plant cells form a cell plate that eventually becomes the new cell wall.

Question 6

Which checkpoint in the cell cycle is most directly influenced by the presence of growth factors?

Accepted Answer

G1 checkpoint

Question 7

What is the primary reason radiation and chemotherapy are effective treatments for cancer?

Accepted Answer

They interfere with cell division, preventing cancer cells from proliferating.

Question 8

Which of the following best explains why human cancer research often uses observational methods rather than controlled studies?

Accepted Answer

Controlled studies are unethical because they would require intentionally exposing people to cancer risk factors.

Question 9

Which of the following statements about homologous chromosomes is correct?

Accepted Answer

Homologous chromosomes carry genes for the same characteristics at the same loci, but may have different versions (alleles) of those genes.

Question 10

What is the chromosome number in human gametes, and what term describes this condition?

Accepted Answer

23 chromosomes; haploid

Question 11

Which of the following accurately describes the outcome of meiosis?

Accepted Answer

Meiosis produces four genetically unique haploid cells.

Question 12

What is the significance of crossing over during meiosis?

Accepted Answer

It increases genetic variation by exchanging segments between nonsister chromatids of homologous chromosomes.

Question 13

If nondisjunction occurs during meiosis II, what is the most likely result?

Accepted Answer

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

Question 14

Which syndrome is caused by an extra copy of chromosome 21?

Accepted Answer

Down syndrome

Question 15

A karyotype is used to detect chromosomal abnormalities. Which step is NOT part of preparing a karyotype?

Accepted Answer

Sequencing the DNA of each chromosome

Question 16

Which of the following is a possible outcome of nondisjunction of sex chromosomes during meiosis?

Accepted Answer

Individuals with a missing or extra X or Y chromosome, such as Turner syndrome (XO) or Klinefelter syndrome (XXY)

Question 17

Which alteration of chromosome structure is most likely to cause cancer if it occurs in somatic cells?

Accepted Answer

Reciprocal translocation

Question 18

Polyploidy, resulting from errors in cell division, is most likely to be observed in which group of organisms?

Accepted Answer

Plants

Question 19

Which equation correctly represents the chromosome number change during meiosis in humans?

Accepted Answer

$$2n \rightarrow n$$

Question 20

If a cell with 46 chromosomes undergoes mitosis, how many chromosomes will each daughter cell have?

Accepted Answer

$$46$$

The Cellular Basis of Reproduction and Inheritance

Study Guide - Practice Questions