Which statement describes an earthworm's digestive opening?
a. It has two digestive openings and no typhlosoles.
b. It has two digestive openings and typhlosoles.
c. It has a single digestive opening and no typhlosoles.
d. It has a single digestive opening and typhlosoles
Ans: b. It has two digestive openings and typhlosoles.
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Discrete packages of light energy are called:
a. pigments b. photons c. positrons d. radioactive waves e. electromagnetic particles
Which of the following statements about the polymerization of macromolecules is false?
A) Often the energy needed for polymerization is supplied by ATP. B) The polymer chain usually has two different ends. C) Water is added to join the monomers of the macromolecules. D) A monomer is usually activated by the coupling of the monomer to a carrier. E) Macromolecules are synthesized by the stepwise addition of monomers.
Island biogeography theory predicts that a 10-fold increase in area results in
A) a 10-fold increase in species number. B) a doubling of species number. C) a tripling of species number. D) no effect on species number.
Which of the following chemical substances contributes to the unique characteristics of acid-fast bacteria?
A. N-acetylglucosamine B. peptidoglycan C. lipoteichoic acid D. endotoxin E. mycolic acid