$$\text{GAATTC}$$ \newline $$\text{CTTAAG}$$

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

Question 1

Which of the following best describes the function of restriction enzymes in bacteria?

Accepted Answer

They cut DNA at specific nucleotide sequences to defend against viruses.

Question 2

Which equation represents the palindromic DNA sequence recognized by the restriction enzyme EcoRI?

Accepted Answer

$$	ext{GAATTC}$$ 
ewline $$	ext{CTTAAG}$$

Question 3

Which of the following is a major point of regulation in gene expression, as illustrated by the tryptophan (trp) operon?

Accepted Answer

Controlling enzyme activity through feedback inhibition

Question 4

In the lac operon, transcription occurs only when:

Accepted Answer

Lactose is high and glucose is low

Question 5

Which of the following best explains why operons are mostly found in prokaryotes?

Accepted Answer

Prokaryotes require coordinated expression of genes for rapid adaptation.

Question 6

What happens to the trp operon when tryptophan concentration is high?

Accepted Answer

Tryptophan binds to the repressor, activating it and blocking transcription.

Question 7

Which of the following is an example of a repressible operon?

Accepted Answer

trp operon

Question 8

Which equation best represents the relationship between DNA, RNA, and protein in gene expression?

Accepted Answer

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

Question 9

Which of the following is a real-world application of restriction enzymes?

Accepted Answer

Cutting plasmid DNA for genetic engineering

Question 10

Which of the following is true about feedback inhibition in the trp operon?

Accepted Answer

The end product (tryptophan) inhibits the activity of the first enzyme in the pathway.

Question 11

Which of the following best describes the role of transcription factors in eukaryotic gene expression?

Accepted Answer

They stimulate transcription by binding to weak promoters.

Question 12

Which scenario would most likely result in the activation of heat shock proteins in a cell?

Accepted Answer

Exposure to high temperatures

Question 13

Which of the following is a key difference between positive and negative regulation of transcription?

Accepted Answer

Positive regulation requires stimulation for transcription to occur, while negative regulation blocks transcription by default.

Question 14

Which of the following best describes the function of the operator in an operon?

Accepted Answer

It is a DNA sequence where the repressor protein binds to regulate transcription.

Question 15

Which of the following is true about the lac operon when glucose is high?

Accepted Answer

High glucose leads to low cAMP, preventing CRP from activating transcription.

Question 16

Which of the following is a plausible outcome if a restriction enzyme cuts a plasmid at two sites?

Accepted Answer

The plasmid is linearized, and DNA fragments are produced.

Question 17

Which of the following best describes the process of feedback inhibition?

Accepted Answer

The end product of a pathway inhibits an earlier enzyme in the pathway.

Question 18

Which of the following is a real-life example of an inducible operon?

Accepted Answer

lac operon

Question 19

Which of the following best explains why cells use only 5-20% of their genes at a time?

Accepted Answer

Gene expression is regulated based on cell type, internal and external conditions.

Question 20

Which of the following best describes the role of cAMP in the regulation of the lac operon?

Accepted Answer

cAMP binds to CRP, activating transcription when glucose is low.

Chapter 18 part 2/2

Study Guide - Practice Questions