In Some Gene Families the Genes Are Clustered in Defined

question 16

Essay

In some gene families the genes are clustered in defined chromosomal regions as a result of ___1____ gene duplication. That often occurs as a result of misalignment of chromatids: over a limited chromosomal region, the DNA sequences are paired but out of register. Subsequent ___2_____ in the mispaired region can generate chromatids with two copies of a gene. Successive gene duplications results in a cluster of highly related genes. Not all the gene copies are functional: some acquire inactivating mutations to become a type of ____3_____ known as a _____4_____ ____3____. In other gene families there may be up to many hundreds of more members scattered across the genome. They often have large numbers of ____5____ ____3______ , also known as ____6_____ that arose by copying the RNA transcripts of a functional gene using a ____7____ _____8_____ to make cDNA copies that integrated into the genome at other locations but subsequently acquired deleterious mutations.

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Definitions:

Cochlear Implants

Electronic medical devices that replace the function of the damaged inner ear by providing a sense of sound to a person who is profoundly deaf or severely hard of hearing.

Taste Buds

Sensory organs located on the tongue responsible for perceiving different tastes.

Papillae

Small projections on the tongue that contain taste buds, which are responsible for detecting taste.

Nerve Hearing Impairment

Hearing loss caused by damage to the auditory nerve or the cochlea, affecting the transmission of sound signals to the brain.