African birds called honeyguides eat beeswax. Most bees’ nests are inside hollow trees where the honeyguides cannot reach them. The honeyguides lead honey badgers, which also eat beeswax, to bees’ nests. The honey badgers then dig out and eat the nests, leaving scraps of wax and honey for the honeyguides. The relationship between the honeyguides and the honey badgers is an example of
A. commensalism.
B. competition.
C. mutualism.
D. predation

!if we removed the wolf, snake, and hawk from this food web, what best explains the impact it would have? a) the number of producers would increase. b)the number of decomposers would increase. c)the number of primary consumers would increase. d)the numbers of primary consumers would decrease.

Lactase is essential for digesting lactose in milk. this enzyme is specific for this sugar. why? molecules and active sites vary in size; only properly sized molecules can fit.there is a precise compatibility between the active site and the lactose molecule.specificity refers to the action of the enzyme, such as hydrolysis, and relatively few molecules can be hydrolyzed.reaction-specific enzymes assume a fit by folding around the most numerous substrate molecules.

After agricultural soils are picked up and carried by a river, how are they deposited in the river’s del which is not a cause of desertification? a) light grazing b) contour plowing c) conversion of rangelands to crop lands d) high population density