On a trip to the beach, Jacob noticed many signs that read "Keep off dunes." His mother told him that walking or digging on the dunes make them vulnerable to erosion. What other human activity would also contribute to the erosion of the sand dunes? a. building new dunes where none exist b. restricting construction near the dunes c. destroying the beach grass on the dunes d. adding sand from the ocean to the dunes

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?

How is mitosis different in plants and animals? a. in animals, the cell membrane pinches together. b. in plants,the dna is one circular chromosomes. c. in plants, there are no sister chromatids. d. in animals, a new cell wall forms.

1. variations in a population of moths allow for some of its members to be able to adapt to environmental changes. the better adapted of the moths will be able to survive the change and thus prevail as the “fittest” of the species. (a) describe three mechanisms in which variation can occur within a species population. (b) explain which mechanism or mechanisms would be responsible for the survival of a population of peppered moths better than white moths in an environment affected by industrial soot. justify your answer.