Which statement best describes a cell membrane?

(1) It is found only in animal cells.

(2) It is a nonliving structure.

(3) It controls reproduction in a cell.

(4) It controls the passage of materials into

the cell.

What happens to a tadpole after about 70 days of life? a. loses its tail b. develops legs c. leaves the water d. is a full adult frog

How do simple and complex organisms carry out life processes differently?

What are recorded observations called? a. hypotheses. b. theories. c. experiments. d. data.

Arrange the following events in the proper sequence for gene cloning. 1 = Incorporate gene into bacterial plasmid. 2 = Isolate DNA from organism containing desired gene. 3 = Incorporate cloned gene into bacterial cells.

Why is clearcutting an especially damaging forestry practice for species that rely upon older trees for their survival? a. Clearcutting removes all trees in a stand, old and young. b. Clearcutting specifically removes older trees in a stand. c.

Which of the following is an example of and std caused by a virus

How are island archipelagos also called island arcs formed.

What is the state in which particles or a substance are mixed with fluid but are undissolved

How many significant figures should the products 62.25 37.4 have

How can biotechnology decrease or increase variation?