The duffy antigen is found in most individuals from western africa. it provides some resistance to malaria. which of these processes would explain why this trait can now be found in many of the white, european populations?
a) gene flow
b) genetic drift
c) natural selection
d) allele reorganization
which physical factors most influence the antarctic ecosystem?
a) climate, rain, erosion
b) plants, wind, and air pressure
c) weather, ice, and ocean currents
d) salinity of water, polar bear population, and snow

Joe is breeding cockroaches in his dorm room. he finds that the average wing length in his population of cockroaches is 4 cm. he chooses the six cockroaches that have the largest wings; the average wing length among these selected cockroaches is 10 cm. joe interbreeds these selected cockroaches. from earlier studies, he knows that the narrow-sense heritability for wing length in his population of cockroaches is 0.6. a. calculate the selection differential and expected response to selection for wing length in these cockroaches. b. what should be the average wing length of the progeny of the selected cockroaches?

Which statement about the immune system is false? a. lymphocytes reduce inflammation, b. b cells remember specific pathogens. c. most white blood cells kill bacteria d. white blood cells are made in lymph nodes.

Which feature of a human community is similar to a niche in a biological community