$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$$

Question 1

Which of the following best describes the difference between prokaryotic and eukaryotic cell division?

Accepted Answer

Prokaryotic cells divide by binary fission, which does not involve mitosis, while eukaryotic cells divide by mitosis.

Question 2

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

Accepted Answer

S phase

Question 3

Which checkpoint in the cell cycle prevents cells with damaged DNA from entering mitosis?

Accepted Answer

G2 checkpoint

Question 4

A scientist observes a cell with homologous chromosomes pairing up and crossing over. Which process is being observed?

Accepted Answer

Meiosis I

Question 5

Which of the following best explains why offspring produced by sexual reproduction are genetically unique?

Accepted Answer

Crossing over and independent assortment during meiosis

Question 6

A cell with 2n = 8 chromosomes undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

$$4$$

Question 7

Which of the following is true regarding sister chromatids?

Accepted Answer

They are identical copies of a chromosome joined at the centromere.

Question 8

In a dihybrid cross between two heterozygous individuals (YyRr x YyRr), what is the expected phenotypic ratio among the offspring?

Accepted Answer

$$9:3:3:1$$

Question 9

Which experiment provided evidence that DNA, not protein, is the genetic material?

Accepted Answer

Hershey and Chase experiment

Question 10

If the DNA template strand reads $$5'	ext{-}ATGCGTACG-3'$$, what is the sequence of the complementary mRNA strand?

Accepted Answer

$$5'	ext{-}UACGCAUGC-3'$$

Question 11

Which enzyme is responsible for adding nucleotides to a growing DNA strand during replication?

Accepted Answer

DNA polymerase

Question 12

What is the function of the TATA box in eukaryotic gene expression?

Accepted Answer

It serves as a promoter region for transcription initiation.

Question 13

Which of the following best describes an exon?

Accepted Answer

A coding region of a gene that is expressed in the final mRNA.

Question 14

Which of the following mutations is most likely to result in a nonfunctional protein?

Accepted Answer

A nonsense mutation

Question 15

In the lac operon of E. coli, what happens when lactose is present and glucose is absent?

Accepted Answer

The lac operon is activated, and genes for lactose metabolism are transcribed.

Question 16

Which of the following mechanisms allows a single gene to code for multiple proteins in eukaryotes?

Accepted Answer

Alternative splicing of exons

Question 17

A mutation deletes three nucleotides from a gene. What is the most likely result?

Accepted Answer

A single amino acid is missing from the protein.

Question 18

Which of the following best describes the Central Dogma of molecular biology?

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 19

Which of the following is a benefit of gene regulation in prokaryotes?

Accepted Answer

It allows cells to conserve energy by producing proteins only when needed.

Question 20

Which of the following best explains why malignant tumors are more dangerous than benign tumors?

Accepted Answer

Malignant tumors invade surrounding tissues and can metastasize to other parts of the body.

Unit III Study Notes: Cell Division, Genetics, and Gene Expression (Chapters 12–19)

Study Guide - Practice Questions