Which of the following kinds of extinction has been linked to collisions of bolides with earth?
A) background extinction
B) mass extinction
C) anthropogenic extinction
Ans: B) mass extinction
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When two genes are located on different chromosomes, ____ of the offspring from a testcross for
genetic linkage should have a recombinant phenotype.
a. over 75% b. about 50% c. about 25% d. about 10% e. about 5%
Which of the following is true of bark?
a) It is composed of phloem plus periderm. b) It is formed by the apical meristems. c) It has no identifiable function in trees. d) It is associated with annuals but not perennials. e) It forms annual rings in deciduous trees.
Which plants are best suited to cool, wet conditions?
A. C4 B. C3 C. CAM D. All types are equally suite E. No plants do.
How can urine contain a higher concentration of wastes (be hypertonic) than the blood?
Select one: a. Urine cannot since the process is passive diffusion. b. Reabsorption of water in the loop of the nephron and collecting ducts leaves behind a more concentrated urine. c. All stages in the kidney involve active transport. d. Urine can be hypertonic for small molecules if it is hypotonic for an equal number of big molecules. e. The whole nephron is impermeable to water.