gas exchange in fish

Question 1

why would lungs not work for water dwelling animals

Answer 1

use to much energy to move water in and out of them

Question 2

gas exchange site of fish

Answer 2

gills

Question 3

how does water move through gills

Answer 3

over them in one direction only- more effective and efficient in energy for fast moving active water animals

Question 4

fish with high oxygen demand

Answer 4

bony fish has high oxygen demands because they are very active

Question 5

why cant their scaly external conduct gas exchange

Answer 5

because the external is not permeable to gases

Question 6

evolved gas exchange of fish

Answer 6

works well in high viscosity and slow rate of oxygen found in water

Question 7

adaptations of gills for gas exchange

Answer 7

-large surface area
-good blood supply to maintain conc gradients
-thin walls for short diffusion
-

Question 8

protection of gills of bony fish

Answer 8

contained in gill cavity and covered by protective bony flap operculum

Question 9

operculum

Answer 9

protective bony flap

Question 10

gill filaments

Answer 10

occur in large stacks

Question 11

features of gill filaments

Answer 11

need water to keep them apart and for exposing large surface area for gas exchange

Question 12

main site of gas exchange

Answer 12

gill lamellae

Question 13

features of gill lamellae

Answer 13

-rich blood supply
give gills filaments for large surface area
-

Question 14

counter current exchange example

Answer 14

blood leaving gulls flows in opposite direction to incoming water- most effective exchange of gases

Question 15

what fish dont have operculum

Answer 15

cartilaginous fish

Question 16

why dont cartilaginous fish have operculum

Answer 16

they have to swim all the time to keep water flowing over mouths and over gills

Question 17

system with operculum with bony fish

Answer 17

evolved do they can ventilate gills what they are not moving

Question 18

counter current exchange system for max efficiency

Answer 18

-maintains steeper gradient
-more than if blood and water flowed in same place
-more gas exchange 80 percent oxygen in bony fish

Question 19

overlapping gill filaments for max efficiency

Answer 19

tips of adjacent gill filaments overlap, increasing resistance of flow of water.
slows down flow of water over gills so more time for exchange to happen