Lesson 1

Question 1

Define gas exchange.

Answer 1

The process by which oxygen reaches cells and carbon dioxide is removed.

Question 2

What is ventilation?

Answer 2

The process of moving the respiratory medium (air or water) over the respiratory surface to maintain a concentration gradient.

Question 3

What is the purpose of ventilation?

Answer 3

To replace stale air high in CO2 with fresh oxygenated air.

Question 4

Define respiration.

Answer 4

A series of chemical reactions that results in the release of energy in the form of ATP.

Question 5

Why do larger organisms need more adaptations for gas exchange?

Answer 5

• Metabolic rate increased for larger organisms
• Longer diffusion distance
• Simple diffusion isn’t sufficient for survival needs

Question 6

How is an amoeba adapted for efficient gas exchange?

Answer 6

• Very large SA:V ratio
• Gas exchange surface is whole membrane
• Permeable membrane allows difusion

Question 7

Describe similarities between flatworms and earthwoms

Answer 7

• Multicellular
• Gas exchange occurs across surface
• Permeable surfaces for diffusion

Question 8

Describe differences between them

Answer 8

• Earthworm secretes mucus to keep moist whereas flatworm lives in aquatic environment
• Earthworm circulates blood to maintain conc. grad. and has tubular shape for more SA
• Flatworm has flattened shape for more SA