Heartburn is caused by ____
a. the gastroesophageal sphincter remaining too tightly closed
b. the gastroesophageal sphincter remaining a little open
c. the pyloric sphincter remaining too tightly closed
d. the pyloric sphincter remaining a little open
e. both the gastroesophageal and the pyloric sphincters remaining too tightly closed
B
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Optimal recovery and identification of anaerobic bacteria in clinical specimens occurs when:
a. the initial incubation period is at 35°C to 37°C for 48 hours. b. plates are incubated for at least 3 days before discarding as negative. c. the initial incubation period is at 35°C to 37°C for 24 hours. d. thioglycollate broth can be inspected daily for 3 days.
Fertilization takes place in the ____________________, and the embryo grows and develops in the
____________________. Fill in the blank(s) with the appropriate word(s).
Most calico cats are female because
A) a male inherits only one of the two X-linked genes controlling hair color. B) the males die during embryonic development. C) the Y chromosome has a gene blocking orange coloration. D) only females can have Barr bodies. E) multiple crossovers on the Y chromosome prevent orange pigment production.
Flattened sacs of internal membranes associated with photosynthesis are called
A. cristae. B. the stroma. C. thylakoids. D. photosystems. E. chloroplasts.