Scientists hypothesize that ____ served as a primitive template for forming polymer chains from organic subunits,
such as amino acids.
a. meteorites that landed in the oceans
b. clay particles in tidal flats
c. sulfur that precipitated out of hydrothermal vents
d. rusty rocks
e. magma spewed from early volcanic activity
ANSWER: b
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Vestigial organs
a. did not have a function when they first developed, but do so today. b. are similar in many organisms. c. must have evolved individually in different organisms. d. are not found in present-day organisms. e. include the human appendix and wisdom teeth and a snake's hipbones.
A taste bud is indicated by
a. A. b. B. c. C. d. A and B. e. none of these; they are olfactory receptors.
Which is the predominant second messenger involved in regulating glucose metabolism?
a. insulin b. glucagon c. adenyl cyclase d. cyclic AMP e. G protein
Which is the correct sequence of embryonic development in eudicots?
a. globular stage embryo ? suspensor embryo ? proembryo ? heart stage embryo b. heart stage embryo ? globular stage embryo ? proembryo ? torpedo stage embryo c. torpedo stage embryo ? globular stage embryo ? heart stage embryo ? suspensor d. proembryo ? torpedo stage embryo ? heart stage embryo ? globular stage embryo e. proembryo ? globular stage embryo ? heart stage embryo ? torpedo stage embry