Which of the following is a common source of heavy metals introduced into natural ecosystems?
A) refuse from mining and smelting operations
B) waste products of manufacturing processes
C) fungicides
D) by-products of burning of leaded fuels
E) all of the above
Ans: E) all of the above
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Which of the following correctly describes the reproduction of males in Daphnia?
A) Daphnia males are produced asexually from unfertilized eggs. B) Daphnia males are produced sexually through fertilization of eggs but are sterile from birth. C) Daphnia males are produced from a pseudo-sexual union of two eggs. D) Daphnia males are produced asexually but are sterile from birth.
You are a landscape architect working on the grounds of a large estate. After you plant a dozen trees, the owner says, "There's been a mistake. The flowers on some of these willow trees look totally different! I specifically asked for Salix alba. You must have planted two different species." You refer to your tree guide, and read: "Salix alba - species of willow native to Europe and Asia, noted for the white undersides of leaves. Insect pollinated, dioecious. Grows 10-30m tall." How do you respond to the client?
A. "Sorry about that sir, I will dig up the wrong trees right away." B. "Don't worry, the trees with the smaller flowers just haven't undergone phase change yet." C. "Don't worry, when the shorter trees reach full size, they will grow the other kind of flower." D. "Don't worry, Salix alba is dioecious, meaning each tree has either male or female flowers. That is why they look different." Clarify Question What is the key concept addressed by the question? What type of thinking is required? Gather Content What do you already know about dioecious species? What other information is related to the question? Choose Answer Given what you now know, what information is most likely to produce the correct answer? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
When studying thermodynamics, one must first define the system. What is included in the system?
a. the universe including all of the planets and stars b. an individual organism, isolated even from the air around it c. the matter and its environment relevant to a particular case of energy transfer d. an ecosystem devoid of living creatures
Using the data in Figure 53-3, the cause of the decline of the wolf population in 1982 was:a
a sharp decrease in food supply. b. a decrease in the intrinsic rate of increase for the wolf population. c. competition with a newly introduced predator. d. introduction of a disease organism. e. cannot be determined from the data provided.