A country's fertility rate suggests zero population growth, but it shows an increase of 20—30 percent over 50 years. What might account for this?
A) lower logistic growth
B) a larger proportion of post-reproductive females
C) better food availability
D) immigration
E) higher environmental resistance
Answer: D
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Based in the information provided, the best explanation for the low numbers of spiders and flies in plot 5 is:
A. centipedes are actively consuming flies and spiders. B. there were not enough spiders to catch and consume all the flies. C. there were not enough flies to support a large centipede population. D. centipedes prefer spiders to flies.
In plants, the sporophyte generation produces _______ as a result of meiosis.
Fill in the blank(s) with the appropriate word(s).
Which of the following is (are) NOT true concerning
glandular epithelium? a. Gland cells occur in it. b. It is found in locations other than glands. c. It secretes products unrelated to its own metabolism. d. Its products are distributed only locally. e. All of these are NOT true.
Reef systems
a. be all be destroyed within 30 years. b. are formed from calcium carbonate secreted by coral polyps. c. have symbiotic dinoflagellates in the living coral. d. have shown widespread bleaching; death of corals is being reported worldwide. e. include all of these.