Epigenetics and Gene Variation

Humans with hypohidrotic ectodermal dysplasia have defects in the formation and function of their sweat glands. Males with the condition have reduced ability to sweat over their entire body. Females with the condition lose the ability to sweat only in patches of skin. Where must the gene that encodes this trait be located?

• in the X chromosome

• in the Y chromosome

• in an autosome

• in chromosome 2

Tags

NGSS.HS-LS3-2

NGSS.HS-LS3-1

A single gene can produce different proteins.

• True

• False

Tags

NGSS.HS-LS1-1

Alternative splicing may be considered a mechanism of gene regulation because it:

• is mutagenic.

• enhances RNA editing

• results in DNA rearrangements.

• results in different protein products.

Tags

NGSS.HS-LS3-2

Gene regulation can occur through:

• histone modification.

• RNA modification.

• DNA modification.

• All of these choices are correct.

The human body contains approximately 200 major cell types. They look and function differently from one another because each:

• has a slightly different genome.

• expresses a different set of genes.

• expresses the same set of genes, but in different orders at different times.

• has a slightly different genome and each expresses a different set of genes.

Methylation, acetylation, and other histone modifications are important because they are associated with:

• cancer genes and their regulation.

• chromatin remodeling and thereby affect gene transcription.

• the environmental and developmental cues that determine whether viral genes and genes in transposable elements are turned off or on.

• All these choices are correct.

Gene regulation by means of epigenetic mechanisms is useful to the organism because it:

• can quickly be reversed.

• can respond rapidly to environmental change.

• can differ between the sexes.

• does not require new mutations.

• All of these choices are correct.

Adding or removing the 5' cap on messenger RNA helps regulate gene activity at the level of translation because the 5′ cap is necessary for:

• translational termination.

• translational initiation.

• 3′ polyadenylation.

• RNA splicing

In a messenger RNA, the 3′ poly a tail: Select all that apply.

• is necessary for RNA splicing.

• changes the rate of transcription.

• alters messenger RNA stability.

• assists with the transport of the mRNA out of the nucleus.

• enhances translation initiation.

Half or more of human proteins may have their synthesis regulated in part by small regulatory RNA.

• True

• False