6.2,6.2,6.3,6.4 gas exchange

Question 1

Explain how an amoeba is adapted for efficient gas exchange ( ficks law)

Answer 1

Oxygen is absorbed across the cell, short diffusion distance and small surface area

Question 2

Explain how an insect is adapted for efficient gas exchange?

Answer 2

Have many spiracles to increase surface area, oxygen goes in tracheoles by muscular contraction to speed up gas exchange

Question 3

Explain how increases in anaerobic respiration allows more efficient gas exchange?

Answer 3

Water moves into cell from tracheoles which increases SA of tracheoles

Question 4

Explain counter current flow?

Answer 4

Countercurrent exchange is the blood and oxygenated water flowing over the lamal in opposite direction

Question 5

Explain why countercurrent flow happens?

Answer 5

To make sure a diffusion gradient for oxygen us maintained across the entire length of the gills

Question 6

Describe the structure of Gills- Filaments, lamallae, Capillaries?

Answer 6

Made up of gill filaments (GF), GF are stacked up in a pile. At right angles to the filaments are GF. increases SA. Gill plates are lined with capillaries to take the oxygen away to sustain a concentration gradient and keeps the diffusion distance short.

Question 7

Explain how a leaf is adapted for efficient as exchange?

Answer 7

Many small pores, stomata, so o cell is far from a stomata aka oxygen. Diffusion distance is small, numerous interconnecting airsac’s in mesophyll cells to maintain concentration gradient, Large SA of mesopyll cells for rapid diffusion.

Question 8

What is the role of the stomata?

Answer 8

they are Minute pores that can open and close to allow more or less oxygen in or carbon dioxide out

Question 9

Explain why CO2 diffuses into the leaf during the day and out at night?

Answer 9

Plant is only photosynthesising during the day but not at night, draws in CO2 at daytime, but plants respire all the time so need to release the CO2 produced during the night time.