At a source the phloem typically has a water potential that is ____ that in surrounding xylem
a. lower than
b. about the same as
c. higher than
d. exactly the same as
e. less negative than
A
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What is the female organ of intercourse which also serves as the birth canal?
a. vagina b. cervix c. uterus d. oviduct e. clitoris
One consequence of the lack of introns in bacterial genes is that
A) exons are eliminated during transcription. B) a 5' cap and poly (A) tail can be added immediately. C) bacterial proteins are very short and not subject to mutation. D) translation can begins before transcription is complete because prokaryotes do not have a nucleus. E) integrated viral DNA is not recognized for transcription.
Blood is pumped at high pressures in arteries from the heart to ensure that all parts of the body receive adequate blood flow. Capillary beds, however, would hemorrhage under direct arterial pressures
How does the design of the circulatory network contribute to reducing blood pressure to avoid this scenario? A) Blood flow through the capillaries is essentially frictionless, and this reduces the amount of pressure on their walls. B) The total cross-sectional diameter of the arterial circulation increases with progression from artery to arteriole to capillary, leading to a reduced blood pressure. C) Fluid loss from the arteries is high enough that pressure drops off significantly by the time blood reaches the capillaries. D) Capillary beds have the thickest walls of any blood vessel to resist these high pressures.
The major food producers for other living organisms is/are
A) higher plants. B) cyanobacteria. C) algae. D) higher plants and algae. E) higher plants, cyanobacteria, and algae.