Question 1

During which phase of the cell cycle does DNA replication occur, and what is the ploidy of the cell immediately after this phase?

Accepted Answer

S phase; diploid with duplicated chromosomes ($$2N)$$

Question 2

Which of the following best describes the difference between mitosis and meiosis in terms of genetic diversity and chromosome number in daughter cells?

Accepted Answer

Mitosis produces two genetically identical diploid cells; meiosis produces four genetically diverse haploid cells.

Question 3

A researcher observes a cell with chromosomes aligned at the metaphase plate, spindle fibers attached to kinetochores, and the nuclear envelope dissolved. Which stage of mitosis is this cell in?

Accepted Answer

Metaphase

Question 4

Which event during meiosis increases genetic variation by exchanging genetic material between homologous chromosomes?

Accepted Answer

Crossing over during prophase I

Question 5

Which of the following statements about cyclins and cyclin-dependent kinases (CDKs) is correct?

Accepted Answer

CDKs are only active when bound to cyclins, and their activity fluctuates with cyclin concentration.

Question 6

A cell is observed to be non-dividing and performing its specialized function. Which phase of the cell cycle is it most likely in?

Accepted Answer

G0 phase

Question 7

Which of the following best explains why elephants have a lower cancer rate than humans?

Accepted Answer

Elephants have more copies of the p53 gene, which activates genes involved in DNA repair and apoptosis.

Question 8

A woman who is heterozygous for an X-linked recessive trait and a man who does not have the trait have a child. What is the probability that their son will express the trait?

Accepted Answer

$$0.5$$

Question 9

Which of the following is a function of tumor suppressor genes such as BRCA1 and BRCA2?

Accepted Answer

Repairing DNA damage and preventing tumor formation

Question 10

A cell undergoes apoptosis. Which of the following events is most characteristic of this process?

Accepted Answer

DNA and proteins are fragmented and packaged into vesicles for removal.

Question 11

Which of the following best describes the law of independent assortment?

Accepted Answer

Alleles for different genes segregate independently during gamete formation.

Question 12

A plant with genotype $$RrYy is $$crossed with another plant with genotype $$rryy. $$What is the probability that an offspring will have the genotype $$Rryy$$?

Accepted Answer

$$0.25$$

Question 13

Which of the following is true regarding the SRY gene?

Accepted Answer

It is located on the Y chromosome and triggers male development.

Question 14

Which of the following chromosomal alterations results in a segment of a chromosome being reversed end to end?

Accepted Answer

Inversion

Question 15

Which protein acts as a relay in the signal transduction pathway from a growth factor receptor and is often mutated in cancers?

Accepted Answer

Ras protein

Question 16

A male is hemizygous for an X-linked gene. What does this mean?

Accepted Answer

He has only one allele for the gene.

Question 17

Which of the following best describes the difference between benign and malignant tumors?

Accepted Answer

Malignant tumors can invade other tissues and metastasize; benign tumors remain localized.

Question 18

Which of the following is true about the formation of Barr bodies?

Accepted Answer

Barr bodies are inactivated X chromosomes found in the somatic cells of females.

Question 19

Which of the following best describes a kinase?

Accepted Answer

An enzyme that attaches phosphate groups to proteins or other molecules.

Question 20

If a cell has a nondisjunction event during meiosis II, which of the following could result?

Accepted Answer

Some gametes will have an extra chromosome (trisomic), and some will be missing a chromosome (monosomic).

Cell Cycle, Cell Division, and Genetics: Exam 4 Study Guide

Study Guide - Practice Questions

Study Guide - Flashcards