The study of physical inheritance among living things is:

What percentage of the species that have ever existed on Earth are probably now extinct?

a. less than 10% b. more than 99.9% c. about 80% d. about 25% e. about 75%

Ferns, whisk ferns, and horsetails are members of this phylum, which has about 13,000 described

living species.

a. Hepatophyta b. Pterophyta c. Bryophyta d. Lycophyta e. Anthocerophyta

The opening and closing of stomata is regulated by changes in

A. water pressure in guard cells B. mesophyll cella wall thickness C. the number of stomata D. chloroplast function

Upon analysis of the primary structure of an unknown protein, it is shown that almost all of the amino acids of this protein are shown to be hydrophobic. What could be said of this protein?

a) Nothing can be discerned about this protein from its primary structure since we cannot predict its structure. b) This protein most likely resides in the cytoplasm. c) This protein is a steroid hormone. d) This protein is most likely a DNA binding protein. e) This protein probably resides in a membrane.