Plant nutrition

Question 1

Leaf adaptations for photosynthesis

Answer 1

1) broad & flat ; larger SA to absorb more sunlight & CO2
2) palisade mesophyll cells contain many chloroplasts ; chlorophyll ; efficient to absorb light
3) spongy mesophyll cells surrounded by many air spaces ; rapid diffusion of gases
4) very thin ; light & CO2 can penetrate easier to reach all mesophyll cells
5) numerous stomata allowing exchange of gases
6) network of veins containing xylem to bring water to the mesophyll cells & phloem to carry away food produce

Question 2

Fate of glucose formed during photosynthesis

Answer 2

• used during respiration to produce energy
• converted into sucrose ; transported along phloem to growing regions & storage organs
• converted into starch ; stored in plant
• converted into cellulose ; new cell walls
• converted into fats & oils ; constituents of cell membrane & storage substance inside seeds
• combine with nitrate ions ; converted into amino acids ; used to make proteins

Question 3

Importance of photosynthesis

Answer 3

• all forms of life depend on the chemical energy found in food produced
• animals, consumers depend directly / indirectly on plants, producers for their food supply
• oxygen produced used for respiration in most organisms
• important role in carbon cycle ; regulating CO2 concentration in atmosphere

Question 4

Limiting factors of photosynthesis

Answer 4

• light intensity
• temperature
• CO2 concentration

Question 5

Importance of nitrogen containing ions

Answer 5

combine with carbohydrates to form :
- chlorophyll
- amino acids
- proteins
- nucleic acids
-> allows healthy growth

Question 6

Deficiency of lack of nitrogen containing ions

Answer 6

poor, stunted growth ;
chlorosis ( small yellow leaves )

Question 7

Importance of magnesium ions

Answer 7

required to make chlorophyll ; part of structure of chlorophyll molecules

Question 8

Deficiency of lack of magnesium ions

Answer 8

small yellow leaves & overall growth reduction