The period of time during which an "explosion" of fossilized animals with bilateral symmetry are first found is the:
A. Ediacaran.
B. Cambrian.
C. Devonian.
D. Jurrasic.
B
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Where does cellular respiration occur?
A) In the chloroplasts B) In the mitochondria C) In the nucleus D) In the airways of the respiratory system
Grizzly bears have large geographic ranges that consist of mosaics of forests and grasslands at varying altitudes. Grizzlies also require relatively pristine water sources in their range. Based on this, what species type best describes grizzly bears?
A. flagship species. B. endemic species. C. indicator species. D. keystone species. E. umbrella species.
Which statement describes suspension feeders?
a. They may inject anticoagulants into a host to inhibit blood from clotting. b. They may have long tongues to effectively extract nectar from plants. c. They may have comblike plates called baleen. d. They may have piercing mouth parts to obtain blood from a host.
One trend in the evolution of animals is the increase in the number of tissue (germ) layers during embryonic development. Flatworms and more complex animals have ________ layers
A) two B) three C) four D) five E) six