When populations become geographically separated for a period and then come back into contact, they __________ become different species.
a) always
b) sometimes
c) never
Answer: b) sometimes
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Which of the following statements is true regarding the fruits produced by angiosperms? Select all correct choices
A. Fruits ripen in response to ethylene. B. Fruits are typically derived from the wall of the ovary. C. Fruits are typically derived from the seed coat. D. Fruits ripen in response to far red light.
Insulin is a peptide hormone. Which of the following would occur in a muscle cell exposed to insulin?
A. Intracellular insulin levels would increase. B. Intracellular glucose levels would decrease. C. It would contract. D. It would secrete glucagon. E. Intracellular second messenger molecule levels would increase.
A small tear in a ligament is called a
1.strain. 2.fracture. 3.bruise. 4.dislocation. 5.sprain.
The urinary system helps to maintain the
extracellular fluid pH by a. synthesizing buffers. b. retaining carbon dioxide in the filtrate. c. excreting excess hydrogen ions. d. combining hydrogen ions with urea. e. signaling the respiratory system to adjust breathing rate.