Question 1

Which of the following best describes the process of dehydration synthesis in the formation of macromolecules?

Accepted Answer

It joins monomers to form polymers by removing water.

Question 2

Which functional group is present in both carbohydrates and nucleic acids and is responsible for their solubility in water?

Accepted Answer

Hydroxyl group $$\mathrm{-OH}$$

Question 3

Which experiment provided direct evidence that DNA is the genetic material in bacteria?

Accepted Answer

Avery, MacLeod, and McCarty's experiment with enzymatic destruction of macromolecules

Question 4

What is the chemical difference between the sugar in DNA and the sugar in RNA?

Accepted Answer

DNA contains deoxyribose (lacking an OH at the 2' carbon), while RNA contains ribose (with an OH at the 2' carbon).

Question 5

Which of the following statements about base pairing in DNA is correct?

Accepted Answer

Purines pair with pyrimidines, maintaining a consistent double helix width.

Question 6

Which enzyme is responsible for unwinding the DNA double helix during replication in bacteria?

Accepted Answer

Helicase

Question 7

In the Meselson-Stahl experiment, what result supported the semiconservative model of DNA replication?

Accepted Answer

After one replication cycle, a single intermediate (hybrid) band was observed.

Question 8

Which of the following is NOT a characteristic required of hereditary material?

Accepted Answer

It must be mutable at a high rate to ensure rapid evolution.

Question 9

Which bond forms between nucleotides in a nucleic acid polymer?

Accepted Answer

Phosphodiester bond

Question 10

Which of the following best explains why DNA replication is both rapid and accurate?

Accepted Answer

DNA polymerase has proofreading activity and base pairing provides a perfect copying mechanism.

Question 11

Which enzyme removes RNA primers and replaces them with DNA during bacterial DNA replication?

Accepted Answer

DNA polymerase I

Question 12

What is the consequence of defective telomere replication in human cells?

Accepted Answer

Chromosomal ends are lost, leading to genomic instability and aging.

Question 13

Which of the following is a correct description of the central structure of an amino acid?

Accepted Answer

A central carbon atom bonded to an amino group, carboxyl group, hydrogen, and a variable R group.

Question 14

Which of the following statements about the Hershey-Chase experiment is correct?

Accepted Answer

Radioactive phosphorus labeled DNA, which was found in the pellet after infection.

Question 15

Which of the following is a purine nucleotide found in DNA?

Accepted Answer

Deoxyadenosine 5'-monophosphate (dAMP)

Question 16

Which of the following best describes the role of topoisomerase (gyrase) during DNA replication?

Accepted Answer

It relaxes supercoiling by cutting and rotating DNA strands.

Question 17

Which of the following is a major difference between DNA replication in bacteria and eukaryotes?

Accepted Answer

Eukaryotes use multiple origins of replication per chromosome, while bacteria use only one.

Question 18

Which of the following statements about the structure of the DNA double helix is correct?

Accepted Answer

The two strands are antiparallel and run in opposite directions.

Question 19

Which of the following is a correct description of the phosphodiester bond formation during DNA elongation?

Accepted Answer

A bond forms between the 3' hydroxyl group of one nucleotide and the 5' phosphate group of the next nucleotide.

The Molecular Basis of Heredity: DNA Structure and Replication

Guida di studio - Domande di pratica