Gas Exchange in Fish

Question 1

What are the adaptation of the gills in a fish

Answer 1

Large surafce area for diffusion
Good blood supply to maintain concentration gradient
Thin walls giving short diffusion distances

Question 2

What is the operculm

Answer 2

bony protective flap that covers the gills of

fish

Question 3

Why is the operculum important

Answer 3

It is important in maintaining flow of water over the gills even if the fish is stationary

Question 4

Where is the main site of gas exchange in a fish

Answer 4

Gill lamellae

Question 5

How is the structure of the gill lamellae suited for gas exchange

Answer 5

Very rich blood supply

Large surface area

Question 6

What happens to the blood leaving the gills

Answer 6

flows in the opposite direction to the incoming water resulting in effective gas exchange

Question 7

What are gills are made up of stacks called

Answer 7

Gill Fillaments

Question 8

How does the gill have a large SA

Answer 8

Each gill lamellae position at right angles to the filament

Question 9

How many layers of gills on both sides of the head

Answer 9

4

Question 10

What is the counter current exchange system

Answer 10

When water flows over the gills in the opposite direction to the flow of blood in the capillaries

Maintains a steeper concentration gradient, the more effective diffusion occurs

Question 11

How does fish maintain a constant flow of water over their gills

Answer 11

Water taken in continuously through the mouth passes backward between the gill bars and over the gill filaments, where the exchange of gases takes place.

Question 12

What does countercurrnet flow ensure

Answer 12

Equilbrimum is not reached meaning diffusion gradient is mainted across the entire length of the gill lamellae

Question 13

How does overlapping ensure gas exchange in fish

Answer 13

Diffusion of substances is slower in water than in gases, Over lapping gills allow as much oxygen as possible to diffuse out

Question 14

How does the tips of adjacent gill filaments help with gas exchange

Answer 14

they overlap which increases the resistance of the flow of water
this slows down the flow of water over the gill surfaces

Question 15

What is the structure of the gills?

Answer 15

Gill filaments occur in a large stack needing water to stop them sticking together
Rich blood supply and large surface area
Blood moves in opposite way to the water allowing for more effective gas exchange