Part 6: The Lungs And Breathing I

Question 1

What is diffusion?

Answer 1

Diffusion is the movement of molecules from an area of high concentration to an area of low concentration.

Question 2

True or False: Diffusion does not require energy input.

Answer 2

True

Question 3

What are exchange surfaces?

Answer 3

Exchange surfaces are surfaces where materials are exchanged between an organism and its environment.

Question 4

Fill in the blank: Exchange surfaces are adapted to maximize ____________ of materials.

Answer 4

Exchange

Question 5

What are some examples of exchange surfaces in organisms?

Answer 5

Examples include the alveoli in the lungs for gas exchange and the small intestine for nutrient absorption.

Question 6

List the factors that would increase the rate of diffusion(4)

Answer 6

Increase in temperature
Higher concentration or particles
Shorter distance
Larger surface area

Question 7

Explain why Amoeba can rely on diffusion without needing an exchange surface

Answer 7

The amoeba is one cell, so the distance between the outside to calm is very small - so diffusion will supply the cell quickly enough

Question 8

Explain why exchange surfaces have the following features:
Large surface area
Thin
Good blood supply (animals only)/Supply of new materials (e.g., breathing in animals)

Answer 8

Large surface area: In the same time period, more particles can diffuse across the exchange surface
Thin: Diffusion is slow, so a shorter distance means this takes less time
Good blood supply (animals only)/Supply of new materials (e.g., breathing in animals): maintains steeper concentration gradient (i.e., keeps a bigger difference between the high and low concentration)