Nutrition in Plants

Question 1

how are leaves adapted for efficient photosynthesis?

Answer 1

1. BROAD= large SA exposed to light
2. most of chloroplasts found in the palisade mesophyll layer= near top of leaf so most light
3. upper epidermis TRANSPARENT= light can pass through
4. xylem + phloem transport water and nutrients needed for photosynthesis.
5. waxy cuticle= reduce water loss by evaporation
6. stomata= efficient gas exchange

Question 2

what is a limiting factor?

Answer 2

SOMETHING THAT STOPS PHOTOSYNTHESIS FROM HAPPENING.
light intensity, CO2 conc. and temp can all be a limiting factor.
Depends on environmental conditions eg. in winter = low temps or at night = light.

Question 3

what 4 minerals do plants need to grow?

Answer 3

Nitrates, Phosphates, Potassium (and magnesium)

Question 4

why do plants contain nitrogen and what is it needed for?

Answer 4

• contain nitrogen for making amino acids and proteins.
• needed for CELL GROWTH
• if a plant doesn’t get enough it will be stunted and older leaves will turn yellow.

Question 5

why do plants contain phosphates?

Answer 5

• contains phosphorus for making DNA and cell membranes
• needed for respiration and growth.
• plants without enough have poor root growth and older leaves are purple.

Question 6

why do plants contain potassium?

Answer 6

• helps enzymes needed for photosynthesis and respiration.

- not enough = poor flower and fruit growth and discoloured leaves.

Question 7

why do plants contain magnesium?

Answer 7

• required for making chlorophyll.

- without = yellow leaves