Unit 3 - Gas exchange and ventilation in bony fish and insects Flashcards Preview

LGS A-Level OCR Biology > Unit 3 - Gas exchange and ventilation in bony fish and insects > Flashcards

Flashcards in Unit 3 - Gas exchange and ventilation in bony fish and insects Deck (10)
Loading flashcards...
1
Q

As organisms get larger, what happens to the size of the diffusion distance?

A

It increases

2
Q

As organisms get larger, what happens to the size of the surface area?

A

It increases

3
Q

As organisms get larger, what happens to the size of volume?

A

It increases

4
Q

As organisms get larger, what happens to the size of the SA:V?

A

It decreases

5
Q

Why do more active organisms have a greater demand for Oxygen and Glucose?

A
  • more energy is required for more movement
  • more ATP must be produced
  • more aerobic respiration must occur
  • more reactants (glucose and oxygen) is required
6
Q

What are the 4 features of efficient exchange surfaces?

A
  • increased SA
  • thin layers
  • good blood supply
  • ventilation to maintain diffusion gradient (for gaseous diffusion)
7
Q

Why does an increased surface area make an exchange surface more efficient?

A

Provides the area needed for exchange surface to overcome the limitations of low SA:V ratio

8
Q

Why do thin layers make an exchange surface more efficient?

A

The distances that substances have to diffuse across are shorter making diffusion quicker

9
Q

Why does a good supply make an exchange surface more efficient?

A

The greater the difference in concentration the greater the rate of diffusion, a good blood supply means substances are constantly being delivered and removed, maintaining the steep concentration gradient

10
Q

Why does ventilation increase the efficiency of a gas exchange surface?

A

Helps to maintain a steep concentration gradient