One scientific hypothesis about the origin of life holds that

A.

RNA replaced DNA as the most stable information-storing molecule.

B.

RNA existed before DNA.

C.

proteins that duplicate themselves came to function in information storage.

D.

as cells evolved they stopped using RNA entirely.

What can be said about farmers in highly developed countries? a) they have little or no negative impact on the environment. b) they practice subsistence agriculture. c) they are able to incorporate polyculture into their farming practices. d) they utilize organic farming techniques on a regular basis. e) they rely on large amounts of energy from fossil fuels.

How are gross production and net production different? a. net production is always greater than gross production. b. net production is always less than gross production. only animals have net production. d. only plants have net production. select the best answer from the choices provided

All of the following statements about enzymes are correct except: proteolytic enzymes are also known as proteases. pectin methyl esterase causes browning of cut fruit. cloud loss in orange juice is due to enzyme activity. proteolytic enzymes in fish cause tissue softening during storage.