Which of the following has the fastest rate of transport?
a. Channel-mediated diffusion
b. Facilitated diffusion
c. Active transport
d. All of the above are equally fast.
Ans: a. Channel-mediated diffusion
You might also like to view...
Communication between cells of the immune system is accomplished in many cases through
A) allelic exclusion. B) clonal deletion. C) cytokines. D) allelic exclusion, clonal deletion, and cytokines.
If a mammal suffered damage to the temperature sensor in its brain, what would be the result?
A. The integrating center would not receive inputs to compare to the set point. Body temperature could rise or fall to dangerous levels. B. Only the integumentary system is required to sense temperature changes. Body temperature would remain stable. C. The animal would have to rely on shivering instead of vasoconstriction to maintain body heat. D. The animal would fall back onto a more primitive ectothermic mode of regulation. Clarify Question What is the key concept addressed by the question? What type of thinking is required? Gather Content What do you already know about temperature regulation? What other information is related to the question? Choose Answer Given what you now know, what information is most likely to produce the correct answer? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
Why was the nucleus removed from the egg cell used to create Dolly, the cloned sheep?
a. to remove the mitochondrial DNA of the egg donor b. to test whether the genetic contribution from a sperm cell alone could produce a lamb c. to create a cloned sheep in the absence of DNA d. since the genome for the clone was supplied by the diploid mammary cell, the presence of the egg cell DNA would result in triploidy e. to see whether egg cell DNA injected into a sperm cell could produce a lamb
The ____ cells are most sensitive to reduced O2 levels
a. heart b. kidney c. liver d. brain e. pancreatic