If a chemical is an inhibitor of the enzyme adenylyl cyclase, which of the following steps in the G-protein signaling pathway would be blocked? a. activation of gene transcription
b. exchange of GTP for GDP
c. ligand bound receptor activation of G-protein
d. synthesis of cAMP

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.

The breakdown of food is accomplished by enzymes. a. physical b. chemical c. mechanical d. none of the above

Parthenogenesis is a type of reproduction that does not require a mate. it’s rarely seen in birds and higher vertebrates. parthenogenesis involves the formation of a zygote. but this zygote is formed without fertilization. in parthenogenesis, in the absence of a male gamete, the ovum develops directly in the zygote.