Gas Exchange In Flowering Plants

Question 1

Leaf structure and its adaption for gas exchange

Answer 1

-Air spaces increase surface area to volume ratio for faster rate of gas diffusion
-Stoma open to allow diffusion of CO2 into leaf during photosynthesis and oxygen and water vapor out leaves
-Leaves thin to provide short diffusion distance for rapid diffusion of gases in and out of leaf
-Leaves flat which provide large surface area for absorption of carbon dioxide during photosynthesis
-Guard cell around stomata control opening and closure of stomata to control gas diffusion in and out of leaves

Question 2

Explain net exchange of gases during day

Answer 2

Respiration take place all time so oxygen taken by respiring cells and carbon dioxide produced as waste product
During day time ligh present allow photosynthesis to occur so carbon dioxide takin in and oxygen taken out
During day rate of photosynthesis higher than rate of respiration carbon dioxide diffuse into leaf and oxygen diffuses out

Question 3

Net exchange of gases during night

Answer 3

No light present so no photosynthesis will occur
Oxygen diffise into leaf and carbon dioxide diffuse out

Question 4

Role of stomata in gas exchange

Answer 4

•In light water enter gaurd cell by osmosis from surrondings epidermis cells
•Guard cells become turgid and swell
•Thick inner walls will split and guard cell will bend outward open stomta
•In dark dark gaurd cells lose water
•Guard cells become flaccid
•Thick inner wall stick together close stomata

Question 5

Gas exchange in relation to respiration and photosynthesis

Answer 5

Co2 use in photosynthesis and produce by respiration where oxygen used in respiration and produced In photosynthesis