Question 1

Which of the following best explains why cloned mammals, such as sheep, often exhibit health problems and shortened lifespans compared to naturally bred animals?

Accepted Answer

Cloning does not always reset epigenetic modifications, leading to abnormal gene expression.

Question 2

In the lac operon of E. coli, what would be the effect of a mutation that prevents the repressor protein from binding to the operator?

Accepted Answer

The operon would be permanently turned on, leading to continuous transcription of lactose-utilization genes.

Question 3

Which process allows a single human gene to produce multiple different polypeptides?

Accepted Answer

Alternative RNA splicing

Question 4

How does DNA packing into chromosomes generally affect gene expression?

Accepted Answer

It blocks gene expression by preventing transcription proteins from accessing DNA.

Question 5

Which of the following is a direct result of X chromosome inactivation in female mammals?

Accepted Answer

One X chromosome in each cell is randomly inactivated, leading to mosaic gene expression.

Question 6

What is the primary function of transcription factors in eukaryotic gene regulation?

Accepted Answer

They promote the binding of RNA polymerase to the promoter region of a gene.

Question 7

A mutation converts a proto-oncogene into an oncogene. What is the likely result?

Accepted Answer

The cell will divide uncontrollably, potentially leading to cancer.

Question 8

Which of the following best describes the role of microRNAs (miRNAs) in gene regulation?

Accepted Answer

They bind to mRNA and either degrade it or block its translation.

Question 9

Why is the development of most cancers considered a slow and gradual process?

Accepted Answer

It results from the accumulation of multiple genetic changes over time.

Question 10

Which of the following mechanisms can regulate gene expression in both prokaryotic and eukaryotic cells?

Accepted Answer

Transcriptional control

Question 11

A scientist uses a DNA microarray to compare gene expression in healthy and cancerous tissue. What information can be obtained from this experiment?

Accepted Answer

Which genes are turned on or off in each tissue type.

Question 12

Which of the following is true about therapeutic cloning?

Accepted Answer

It aims to produce embryonic stem cells for medical treatments.

Question 13

What is the main difference between embryonic stem cells and adult stem cells?

Accepted Answer

Embryonic stem cells can give rise to all cell types, while adult stem cells are usually limited to a few types.

Question 14

Which of the following best explains why tortoiseshell coat patterns are only seen in female cats?

Accepted Answer

X chromosome inactivation leads to mosaic expression of coat color genes in females.

Question 15

Which of the following is a possible outcome when a microRNA (miRNA) binds to a target mRNA?

Accepted Answer

The mRNA is degraded or its translation is blocked.

Question 16

What is the role of homeotic genes in animal development?

Accepted Answer

They regulate groups of other genes that determine the anatomy of body parts.

Question 17

Which of the following best describes the process of signal transduction in cell signaling?

Accepted Answer

A signal molecule binds to a receptor, triggering a series of molecular changes that lead to a cellular response.

Question 18

Which of the following lifestyle choices can help reduce the risk of developing cancer?

Accepted Answer

Avoiding tobacco, eating a healthy diet, and protecting skin from UV radiation.

Question 19

A mutation in the p53 tumor-suppressor gene results in a nonfunctional protein. What is the likely consequence for the cell?

Accepted Answer

The cell will lose its ability to inhibit cell division, increasing cancer risk.

Regulation of Gene Expression, Cloning, and the Genetic Basis of Cancer

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