Some traits are polygenic but do not show typical continuous distributions. For example, type II diabetes is determined by a number of genes, but one is either diagnosed as diabetic or not diabetic based on blood sugar levels
How might one explain such a phenomenon?
In some cases, a physiological threshold may be crossed such that in the presence of a given proportion of related genes expression occurs. Often, the environment plays a role in expression and therefore, along with genetic makeup, diagnosis of the condition.
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Which body of evidence is least supportive of plate tectonics theory?
a. the worldwide fossil record b. the global distribution of existing species c. the sea-floor spreading d. the shape of the continents e. the size of the oceans
Which cells are produced during meiosis I?
a. spermatogonia b. primary spermatocytes c. secondary spermatocytes d. spermatids e. sperm
The problems associated with slash-and-burn agriculture are most closely related to:
a. greed by international corporations. b. overpopulation of indigenous people. c. consumption by highly developed countries. d. cattle ranching. e. timber for export.
Broca’s area is involved in:
a. sensing sound waves. b. speech comprehension. c. the movement of vocal chords. d. the recognition of spoken words. e. the recognition of written words.