Which structure in the development of the amphibian is equivalent to the primitive knot in bird
development?
a. the archenteron
b. the dorsal lip of the blastopore
c. the ventral lip of the blastopore
d. ectoderm
e. endoderm
B
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Why do fungi produce fruiting bodies?
A. to enhance spore dispersal B. to provide food for animals C. to enhance photosynthesis D. to defend against predators E. to indicate territorial boundaries
An atom is best characterized as ________ .
a. a structural unit of interacting tissues b. an organized array of cells that interact in a collective task c. a fundamental unit of all substances, living or not d. the smallest unit of life e. a biological complex made up of smaller units called molecules
Mutations that occur in somatic cells are:
A) responsible for the appearance of human diseases such as sickle-cell anemia. B) always harmful. C) never harmful. D) passed on to successive generations when they are incorporated into gametes. E) not passed on to future generations.
Chemical reactions are reversible; they can proceed in both the forward and reverse directions
If the ?G° for the reaction Y->X is energetically favorable, how can you explain the fact that not all of the Y molecules will be converted to X molecules?