Mutations in the DFNA20/26 Locus,which Codes for the Actin Gamma

question 33

Multiple Choice

Mutations in the DFNA20/26 locus,which codes for the actin gamma 1 protein,are associated with congenital deafness.An irate senator complains that government money is being wasted on studies of this mutant gene -- in yeast! "I am no biologist," says the senator,"but I am pretty sure yeast don't have ears." How do you respond?

• A)"You are right,Senator -- yeast do not have ears.We should revoke the funding immediately."
• B)"We can learn valuable information about the structure of the mutant protein by expressing it in yeast.It is difficult to collect large amounts of actin from tiny hair cells,and unethical to collect it from human patients."
• C)"We can learn valuable information about the transcription of the mutant gene in yeast.It is much more difficult to study transcription in human cells."
• D)"We can learn valuable information about sound transmission through the mutant yeast.By placing a speaker against a yeast vial and recording sound from the other side,we can infer how the mutant actin affects sound waves."

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Definitions:

Epithalamus

A portion of the diencephalon in the brain, involved in linking the limbic system to other parts of the brain and regulating hormones and circadian rhythms.

Habenula

The habenula is a small region in the brain involved in regulating sleep-wake cycles, reproductive behavior, and stress responses.

Pineal Gland

is a small endocrine gland in the brain involved in the production of melatonin, regulating sleep patterns.

Mammillary Bodies

Paired structures in the brain involved in memory function, part of the limbic system.