The Histone Proteins Are Among the Most Slowly Evolving Proteins

question 79

Essay

The histone proteins are among the most slowly evolving proteins. For example, a histone protein called histone H4 in cows and peas differs by only 2 amino acids among a total of about 100. Suggest a reason why histone proteins evolve so slowly.

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Definitions:

Dermis

The dermis is the thick layer of living tissue below the epidermis that forms the true skin, containing blood capillaries, nerve endings, sweat glands, hair follicles, and other structures.

Tyrosinase

An enzyme critical in the production of melanin and other pigments from tyrosine by oxidation.

Ultraviolet Light

A form of electromagnetic radiation with a wavelength shorter than that of visible light but longer than X-rays, known to cause skin damage and beneficial for producing vitamin D.

IEP Meeting

A meeting concerning an Individualized Education Program, where educators, parents, and specialists plan educational accommodations for a student with disabilities.