The first life on Earth was
A. prokaryotic.
B. eukaryotic.
C. prokaryotic and multicellular.
D. eukaryotic and multicellular.
E. eukaryotic and unicellular.
Answer: A. prokaryotic.
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Environmental variation can be used to describe why:
A. Identical twins have different weights. B. Leaves on a single tree turn color at different times in the fall. C. One tomato in a carton spoils before the rest. D. A litter of puppies has siblings of varying sizes. E. All of the above are correct.
Answer the following statements true (T) or false (F)
1. When Schmidt-Nielsen and his colleagues followed a "pulse" of air through the respiratory system of an ostrich, it took two full cycles of inhalation and exhalation for this pulse to pass through and be exhaled. 2. Chemoreceptors for oxygen normally play the most important role in regulating breathing rate. 3. Smaller mammals typically have higher ventilation rates than large mammals. 4. The shape of the oxygen-hemoglobin dissociation curve is a straight line. 5. Asthma attacks result from contraction of the muscles surrounding the bronchioles.
In ________ countries, the doubling time is often small
Fill in the blank(s) with correct word
The probability of extinction via predation is particularly high when:
a. Predator and prey coevolved over long periods of time. b. Prey populations are stressed by additional environmental factors. c. Predators are a new arrival to the prey's habitat. d. The prey species is long lived and has a low birthrate. e. B, C, and D.