Question 1

Which of the following statements best explains why DNA is more stable than RNA under physiological conditions?

Accepted Answer

DNA has a deoxyribose sugar lacking a 2'-OH group, reducing its reactivity compared to RNA.

Question 2

During DNA replication, which enzyme is responsible for synthesizing short RNA primers to initiate DNA synthesis?

Accepted Answer

Primase

Question 3

A mutation changes the codon UAU (tyrosine) to UAA in an mRNA sequence. What type of mutation has occurred?

Accepted Answer

Nonsense mutation

Question 4

Which of the following best describes the difference between the leading and lagging strands during DNA replication?

Accepted Answer

The leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments called Okazaki fragments.

Question 5

Which of the following base pairing rules is correct for transcription from DNA to RNA?

Accepted Answer

A pairs with U, T pairs with A, G pairs with C, C pairs with G

Question 6

A scientist creates an artificial bilayer using liposomes to study drug delivery. What property of phospholipids makes this possible?

Accepted Answer

Phospholipids are amphipathic, containing both hydrophilic and hydrophobic regions.

Question 7

Which of the following molecules would diffuse most rapidly across a phospholipid bilayer?

Accepted Answer

H\_2O

Question 8

During translation, what is the function of the ribosome?

Accepted Answer

It reads the mRNA codons and assembles amino acids into a polypeptide chain.

Question 9

Which of the following best describes a missense mutation?

Accepted Answer

A mutation that changes one amino acid in the protein sequence.

Question 10

If the DNA template strand has the sequence 3'-CTA GGA TAC-5', what is the corresponding mRNA sequence produced during transcription?

Accepted Answer

$$5'	ext{GAU CCU AUG}3'$$

Question 11

Which of the following statements about DNA polymerase is correct?

Accepted Answer

DNA polymerase requires an RNA primer to initiate synthesis.

Question 12

What is the role of telomerase in eukaryotic cells?

Accepted Answer

It extends the ends of chromosomes to prevent loss of genetic material during replication.

Question 13

Which of the following best describes the structure of a phospholipid?

Accepted Answer

A molecule with a hydrophilic head and two hydrophobic tails.

Question 14

A patient is found to have a mutation in the gene encoding DNA ligase. Which process would be most directly affected?

Accepted Answer

Joining Okazaki fragments on the lagging strand during DNA replication.

Question 15

Which of the following is true regarding the genetic code?

Accepted Answer

AUG is the start codon and codes for methionine.

Question 16

Which process is responsible for transferring genetic information from DNA to mRNA?

Accepted Answer

Transcription

Question 17

A cell is exposed to a chemical that inhibits RNA polymerase. Which process will be directly affected?

Accepted Answer

Transcription

Question 18

Which of the following statements about saturated and unsaturated fatty acids is correct?

Accepted Answer

Unsaturated fatty acids have at least one double bond, making them more likely to be liquid at room temperature.

Question 19

Which of the following is a consequence of a frameshift mutation in a coding region of a gene?

Accepted Answer

The reading frame of the mRNA is altered, potentially changing all downstream amino acids.

DNA, RNA, Replication, Transcription, Translation, Mutations, and Biological Membranes: Study Notes

Study Guide - Practice Questions