Which of the following is characteristic of sponges and hydras?
a. lack of an actual circulatory system
b. lack of a reproductive system
c. lack of a digestive system
d. lack of a muscle system
Answer: a. lack of an actual circulatory system
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The bones of a bird's wing are similar to the bones of a bat's wing. This observation is an example of _____
a. uniformity b. evolution c. comparative morphology d. a lineage
If atom X contains 14 protons, 13 electrons, and 12 neutrons, and atom Y contains 14 protons, 14
electrons, and 12 neutrons, then you conclude that:a. Y is an ion but X is not. b. X and Y are both ions. c. X and Y both have filled valence shells. d. X and Y are isotopes of the same element. e. X and Y are atoms of the same elem
Arrange the following stages of oogenesis in sequential order
1) secondary oocyte 2) oogonium 3) ovum 4) primary oocyte a. 4 ? 1 ? 2 ? 3 b. 4 ? 3 ? 2 ? 1 c. 3 ? 2 ? 4 ? 1 d. 2 ? 3 ? 4 ? 1 e. 2 ? 4 ? 1 ? 3
Which of the following best describes the behavior of a gated channel?
(a) It stays open continuously when stimulated. (b) It opens more frequently in response to a given stimulus. (c) It opens more widely as the stimulus becomes stronger. (d) It remains closed if unstimulated.