ANTHROP 2FF3 Study Guide - Final Guide: Body Shape, Melanocyte, Homeostasis

• School: McMaster University
• Department: Anthropology
• Course: ANTHROP 2FF3
• Professor: Ann Herring

Document Summary

* hemoglobin --> carried oxygen (gives reddish tinge) * melanin --> absorbs uv rays, prevents damage to dna. * carotene --> from food plants (yellowish cast) Polygenetic trait: trait controlled by more than one gene. Determined by amount of melanin, hemoglobin, carotene in the skin. Melanin (produced by melanocytes) absorbs uv light --> protects from sunburn. Darker skin = greater melanocyte activity, not more melanocytes. Darker skin - closer to equator, lighter skin - farther away from equator. Cline: gradual change in the frequency of a trait or allele in populations dispersed over geographical space. Closer to equator, more uv (darker skin), father away from equator, less uv (lighter skin) Vitamin d essential for normal bone growth and mineralization. Lack of vitamin d can cause rickets in children --> bones become soft. Vitamin d synthesized when exposed to uv radiation. Darker skin would inhibit synthesis of vit d. Lighter skin --> in areas with less uv radiation; sufficient vitamin d.