Plant Nutrition

Question 1

What are the layers of the leaf from top to bottom?

Answer 1

Waxy cuticle
Upper epidermis
Palisade mesophyll cells
Xylem
Spongy mesophyll
Guard cells

Question 2

How is the spongy mesophyll layer adapted for photosynthesis?

Answer 2

contains air spaces - allows carbon dioxide to diffuse through leaf

Question 3

How is the large & thing shape of a leaf adapted for photosynthesis?

Answer 3

• large surface area for light absorption
• short diffusion distance for carbon dioxide

Question 4

How is the palisade layer adapted for photosynthesis?

Answer 4

contains lots of chloroplasts at top of leaf to maximise light absorption

Question 5

How is fewer stomata at top of leaf a good adaption for photosynthesis

Answer 5

reduces water loss by transpiration

Question 6

How is the waxy cuticle layer adapted for photosynthesis?

Answer 6

prevents water loss

Question 7

How is the epidermis layer adapted for photosynthesis?

Answer 7

thin & transparent - allows more light to reach palisade cellls

Question 8

Where does photosynthesis take place?

Answer 8

chloroplasts

Question 9

What is the word equation for photosynthesis?

Answer 9

water + carbon dioxide (+ light) to glucose + oxygen

Question 10

What is the symbol equation for photosynthesis?

Answer 10

6H2O + 6CO2 to C6H12O6 + 6O2

Question 11

What factors affect photosynthesis?

Answer 11

• availability of water, carbon dioxide & light - reactants - without them it can’t happen
• temp. - too low - enzymes move slowly, too high - denaturation, since it’s an enzyme catalysed reaction
• pH - extreme - enzyme denaturation

Question 12

What do the stomata do?

Answer 12

control gas exchange
can open/close depending on how turgid guard cells are

Question 13

Why do stomata open/close?

Answer 13

regulate transpiration
allow gas exchange

Question 14

What mineral ions are needed for plants and why?

Answer 14

• magnesium - used to make chlorophyll
• nitrates - used to build proteins for growth & repair