Which occurs during winter in the northern hemisphere?
a. the earth is closer to the sun.
b. the earth's axis is tilted so that the northern hemisphere faces the sun.
c. the earth's axis is tilted so that the northern hemisphere faces away from the sun.
d. the earth is farther away from the sun.

Which allele combination represein a dihybrid cross for round and yellow seeds (rryy x rryy), what is the probability of having green and wrinkled seeds? nts a male who has an x-linked recessive disorder? which allele combination represents a male who has an x-linked recessive disorder?

Common commercial benefits of microorganisms include synthesis ofa. insulin. b. antibiotics. c. aspirin. d. antibiotics and aspirin. e. antibiotics and insulin.

Juan and carol were studying invertebrates in biology. they knew that segmented or earth worms preferred a dark, moist habitat. during this lab, they would be investigating the responses of organisms called planaria or dugesia tigrina. these were simple flatworms that still had a one-way digestive system and a very simple nervous system. juan and carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. they shined a light on the dish. next, they removed the paper and placed a small amount of chicken liver at one end of the dish. they added a few large salt crystals to the water. finally, they added drops of hot water to the cool water in the petri dish. their results can be seen in the data table. according to their experiment, all but one conclusion is valid.