Which of the following is a way in which humans have worked to protect certain species?

The diagram shows a fossil of an ancient whale skull and a skull of a present-day whale. the ancient whale is extinct and is believed to be an ancestor of the present-day whale. what do these skulls most likely show that supports darwin’s theory of evolution? all populations can adapt and survive. only some organisms have a common ancestor. populations change slowly over time. populations rapidly become extinct.

What would be the result if crossing over did not happen during meiosis in humans? a. there would be less genetic variation in humans. b. parents would be more likely to look like their children. c. the human population could not reproduce. d. children would have more chromosomes.

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?