In influenza viruses, minor annual variations in the antigenic makeup caused by mutations are called
a) antigenic drift.
b) antigenic shift.
c) mutation.
d) recombination.
Ans: a) antigenic drift.
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Define the following terms:
(a) myopia: (b) hyperopia: (c) presbyopia:
The exchange of oxygen and carbon dioxide occurs in the human lungs in the ____
a. bronchi b. alveoli c. bronchioles d. trachea e. glottis
The ________ is the distance between the center of a lens and the point at which it focuses parallel beams of light.
Fill in the blank(s) with the appropriate word(s).
Which of the following statements about animal connective tissues is true?
(a) Enzymes embedded in the plasma membrane synthesize the collagen in the extracellular matrix extracellularly. (b) In connective tissue, the intermediate filaments within the cells are important for carrying the mechanical load. (c) Cells can attach to a collagen matrix by using fibronectin, an integral membrane protein. (d) Proteoglycans can resist compression in the extracellular matrix.