Gas Exchange In Plants

Question 1

Respiration equation

Answer 1

Oxygen + glucose = carbon dioxide + water

6O2 + C6H12O6 = 6CO2 + 6H2O

Question 2

Photosynthesis equation

Answer 2

Water + carbon dioxide = oxygen + glucose

Question 3

Waxy cuticle

Answer 3

Clear to let light in and prevents water loss

Question 4

Chloroplasts

Answer 4

Near the top of the leaf for lots of light for photosynthesis

Question 5

Air spaces

Answer 5

Provide a short diffusion distance for gas exchange

Question 6

Guard cells

Answer 6

Open and close stomata

Question 7

Stomata

Answer 7

Let gases in and out, open wider in the light because photosynthesis is occurring but at night only respiration occurs so not as much air and waste (02 from photosynthesis, CO2 from respiration) air is being produced or needed.

Question 8

Layers of the leaf:

Answer 8

Upper epidermis
Palisade layer: tightly packed, where most photosynthesis occurs
Spongy mesophyll: large surface area
Lower epidermis

Question 9

Bicarbonate indicator

Answer 9

• CARBON DIOXIDE dissolves in water to form a weak acid (detects changes in acidity)

• purple-no CO2
• red-little CO2
• yellow-lots of CO2

Question 10

Different rates of CO2 produced

Answer 10

Light: more photosynthesis than respiration so more O2 is being produced
Dark: no photosynthesis is being produced but respiration is still occurring, therefore overall CO2 production

Question 11

Testing leaf for starch

Answer 11

• dark room to destarch it
• hot water for 5 minutes to stop chemical reactions like photosynthesis and to soften waxy cuticle
• 5 minutes in hot ethanol to remove chlorophyll
• test for starch

Question 12

Respiration equation

Answer 12

Aerobic:
Glucose + oxygen -> water + carbon dioxide

Anaerobic:
In animals: glucose -> lactic acid

In yeast and plants: glucose -> ethanol + carbon dioxide