Plant Nutrition

Question 1

Define photosynthesis.

Answer 1

The process by which a plant manufactures carbohydrates from raw materials in the presence of light and chlorophyll.

Question 2

Recite the chemical reaction for photosynthesis.

Answer 2

6CO2+6H2O (with light and chlorophyll) —> C6H12O6+6O2

carbon dioxide+water —> glucose+oxygen

Question 3

Explain the forms that sugar takes on in a plant and why.

Answer 3

Glucose in a plant is changed into sucrose and starch.
Glucose is very reactive and is quickly used up, and can’t be stored.
It is transported as sucrose and stored as starch.

Question 4

Name the parts of the leaf.

Answer 4

Lamina (leaf blade)
Midrib (central vein)
Veins
Petiole (stalk joining leaf and stem)

Question 5

Name the parts in the internal structure of a leaf and their functions.

Answer 5

Wax cuticle= Protective, prevents water loss and overheating.
Epidermis= Protective, prevents water loss and overheating.
Palisade mesophyll layer= long to maximise surface area and contains lots of chlorophyll.
Spongy mesophyll layer= allows air to travel to the palisade cells and gaseous exchange to occur.
Stomata= allows air to come in and out of the leaf.
guard cells= control opening and closing of stomata.
Vascular bundles= contain xylem and phloem.
Xylem= Transports water into leaf and structural support.
Phloem= transports sugars made in leaves to other parts of plant and structural support.