Your textbook authors make the claim that "sympatric species with matching chromosome numbers are rare." Why is this?
A) because allopatric speciation is far more common
B) because sympatric speciation has only been hypothesized but not documented
C) because coexisting populations need a boundary to gene flow before divergence can occur, and differences in chromosome numbers provide this
D) because macroevolution is just a theory
C
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The adhesion step in extravasation is most likely to be mediated by:
A. integrin proteins. B. cell wall proteins. C. collagen. D. keratin.
The main class of neurotransmitters involved in regulating mood in vertebrate animals is/are
A. the biogenic amines. B. acetylcholine. C. amino acids. D. gases such as nitric oxide and carbon monoxide. E. acetylcholine and amino acids.
Describe how amniocentesis is used in the prenatal diagnosis of human genetic abnormalities. Then
compare and contrast the benefits and risks associated with amniocentesis and chorionic villus sampling. What will be an ideal response?
A warning sign of possible cancer would be any of the following EXCEPT:
A) persistent, unusual bleeding B) a change in bowel habits C) sudden development of fever, nausea, and diarrhea D) a change in shape, color, or surface of a skin lesion