Ciliated gills in clams, sharks continuously swimming with their mouths partly open, countercurrent flow of blood and water in fish gills, and the use of air sacs to effect unidirectional flow of air through bird lungs are all adaptations that optimize what factor in the formula for Fick’s Law of diffusion?

Question

A.  D
B.  A
C.  Dp
D.  d

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 diffusion? 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?

Answer 1

C.  Dp

Clarify Question
What is the key concept addressed by the question?
        · This question is asking you to identify the components of Fick’s Law of Diffusion.
What type of thinking is required?
        · Apply level:
            o You are being asked to take what you already know and use, or apply, it to the understanding of how vertebrate structures factor into Fick’s Law of Diffusion What type of thinking is required?

Gather Content
What do you already know about diffusion? What other information is related to the question?
        · Diffusion is the movement of a substance from high concentration to low concentration.
        · The greater the difference between the area of high concentration and low concentration, the faster diffusion occurs.
        · In the gas exchange that occurs to sustain life, oxygen diffuses from an area of high concentration in the environment to an area of low concentration in the organism.
 
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · Ciliated gills in clams place blood near water, where oxygen can be taken up.
        · The continual swimming with an open mouth exhibited by sharks insures that a steady stream of water with a relatively high oxygen content will flow past the gills, which contain blood with a lower oxygen content.
        · These adaptations would maximize delta p, which is the difference in pressure between the environment and the location of gas exchange.
        · As delta p increases, gas exchange occurs more rapidly.
 
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?
        · Apply level:
            o Answering this question correctly depended on your ability to use vertebrate structures in a new situation. If you got an incorrect answer, did you remember that each of the mentioned structures maximize the difference between blood oxygen levels and the oxygen levels of the environment, or that the difference in these levels is a component of Fick’s Law of Diffusion? Did you have trouble extending the nature of the vertebrate structures to determine the correct answer?