Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species?
a. river otter
b. mouse living in a temperate broadleaf forest
c. mouse living in a desert
d. beaver

What can happen to an enzyme as tempature rises

Which statement about variation is true? a) all phenotypic variation is the result of genotypic variation. b) all genetic variation produces phenotypic variation. c) all nucleotide variability results in neutral variation. d) all new alleles are the result of nucleotide variability. e) all geographic variation results from the existence of clines.

What is the difference between the type of smog experiences by cities in the eastern united states and that found in southern california?