In the countercurrent exchange in a fish's gills, the oxygen concentration is always _______ in the water than the blood along the entire pathway of each lamella.
A. higher
B. the same
C. lower
A. higher
You might also like to view...
An advantage of YACs over other vectors in cloning human genes is that they ____
a. are taken up more readily by recipient cells b. have a higher capacity for carrying long DNA fragments c. are less likely to trigger cell rejection d. resemble a human chromosome more closely than do other vectors e. carry long regions of human-like DNA
The main difference between adventitious roots and other root types is that
A. adventitious roots are formed from any part of the plant other than the root. B. other specialized root types do not provide the same advantages as adventitious roots. C. there is no woody or starch storage tissue within the adventitious roots. D. adventitious roots do not conduct water or nutrients for the plant, as do other specialized root types. E. None of the answer choices is correct.
Refer to Figure 26-2. The process occurring in the cells labeled 2 in the sequence is:
a. fertilization.
b. syngamy.
c. the first meiotic division.
d. the second meiotic division.
e. mitosis.
The way in which an organism utilizes its environment may be called
A. resource partitioning. B. its habitat. C. intraspecific competition. D. competitive exclusion. E. its niche.