Which of the following statements about sterols is true? A) All sterols share a fused-ring structure with four rings. B) Sterols are found in the membranes of all living cells. C) Sterols are soluble in water, but less so in organic solvents such as chloroform. D) Cholesterol is the principal sterol in fungi. E) The principal sterol of animal cells is a hopanol.

Which term best describes a community in which people work mostly in factories? a. agricultural. b. hunting and gathering. c. domesticated. industrial.

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.

Skulls of homo sapiens were found during an excavation. the skulls were preserved because the bodies were frozen. so, these fossils are ( 1 ) fossils. ( 1 ) a. mineralized b. mold c. original-tissue