Which of the following is true of red blood cells? a. they have multiple nuclei b. once created in bone marrow, they circulate for our lifetime c. they live for only 120 days d. they live for only about 20 days

Which of these correctly describes the difference between processes that take place in prokaryotic and eukaryotic cells?

Label the offspring chromosomes a1, a2, b1, or b2. circle any mutation chromosomes.

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the correspondingbones in whales have very different shapes and proportions. however, genetic data suggest that all three kindsof organisms diverged from a common ancestor at about the same time. which of the following is the mostlikely explanation for these data? a) humans and bats evolved by natural selection, and whales evolved by lamarckian mechanisms.b) forelimb evolution was adaptive in people and bats, but not in whales.c) natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.d) genes mutate faster in whales than in humans or bats.e) whales are not properly classified as mammals.