Gene Regulation Review

Which statement best defines gene regulation and expression?

• The permanent change in the DNA sequence of a gene

• The turning on and off of a gene within a cell in response to stimuli

• The random activation of all genes in every cell

• The replacement of genes when exposed to toxins

Two cells in a multicellular organism have the same DNA. According to the passage, why might they function differently?

• They have different DNA codes

• They express different sets of genes

• They are from different species

• One cell has no proteins

Which is an example of an environmental factor that can affect gene expression?

• Number of chromosomes

• Temperature

• Nucleotide shape

• Mitosis rate

Hormones are described as an internal chemical factor. What role do they play in gene expression according to the passage?

• They delete genes permanently

• They turn on genes related to processes such as puberty

• They prevent all protein production

• They change DNA sequence to adapt to the environment

A pair of identical twins grows up in different environments. Based on the passage’s ideas about epigenetics, which outcome is most likely?

• They will have completely different DNA sequences

• They may show differences in traits because environmental factors altered gene activity without changing DNA

• They will always look and behave identically regardless of environment

• They cannot be affected by hormones

Which statement best describes gene regulation as shown in the visuals?

• It determines which part of the DNA is expressed in a cell.

• It describes how DNA is copied before cell division.

• It identifies the number of chromosomes in a cell.

• It explains how mutations permanently change DNA sequences.

Skin cells and white blood cells contain the same DNA, yet they perform different functions. Based on the material, what is the most direct reason for this difference?

• Different genes are expressed to make different proteins in each cell type.

• Skin cells have less DNA than white blood cells.

• White blood cells do not translate any genes to proteins.

• Skin cells and white blood cells come from different organisms.

Which statement best defines gene regulation?

• The process of copying DNA into RNA

• What part of the DNA is activated in a cell

• How amino acids join to form proteins

• The location of chromosomes in the nucleus

A heart cell and a small intestine cell contain the same DNA sequence. Why do they perform different functions?

• They have different numbers of chromosomes

• Different parts of their DNA are activated, leading to different proteins

• Heart cells do not use RNA while intestine cells do

• Only intestine cells undergo transcription and translation

Which statement best explains how cells with the same DNA can develop different structures and functions?

• Different cells have different DNA sequences.

• Epigenetic markers can turn genes on or off without changing the DNA sequence.

• Cells randomly ignore most of their genes.

• DNA is removed from cells that do not need it.