If a man has red-green color blindness, a sex linked dominant trait, what is a possible genotype of his father? I. XR Y
II. Xr Y
III. XR XR
IV XR Xr
A. I and II
B. I, III, and IV
C. Only III
D. I and III

What happens when a magniseum ion ia atracked to a chlrene ion

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.

Which of the following types of pollution is most responsible for large numbers of deaths worldwide because of unsafe drinking water? (a) nutrient pollution (b) thermal pollution (c) pathogen pollution (d) sediment pollution