Nutrition In Plants

Question 1

What are the conditions needed for photosynthesis?

Answer 1

Sunlight, carbon dioxide and chlorophyll

Question 2

What happens during the light-dependent stage of photosynthesis?

Answer 2

Light energy is absorbed by chlorophyll and converted into chemical energy , light energy is used to split water molecules;es into oxygen and hydrogen atoms aka photolysis of water

Question 3

What happens during the light-independent stage?

Answer 3

Hydrogen produced in photolysis is used to reduce carbon dioxide to carbohydrates such as glucose. Energy required comes from the light dependent stage.

Question 4

What is photosynthesis?

Answer 4

The process in which light energy absorbed by chlorophyll is transformed into chemical energy that is used to synthesise carbohydrates from water and carbon dioxide. Water and carbon dioxide are the raw materials for photosynthesis and oxygen is produced during the process

Question 5

What is the overall equation for photosynthesis (molecular equation)

Answer 5

Chlorophyll
6CO2 + 12H2O ——————> C6H12O6 + 6O2 + 12H2O
Light energy

Question 6

What is the overall word equation for photosynthesis?

Answer 6

Chlorophyll
Carbon dioxide + water —————-> glucose + oxygen
Light energy

Question 7

What are the limiting factors in photosynthesis? (Factors affecting the rate of photosynthesis)

Answer 7

• light intensity
• carbon dioxide concentration
• temperature

Question 8

What happens to the glucose formed during photosynthesis?

Answer 8

• used immediately for cellular respiration to provide energy for cellular activities & to form cellulose cell walls
• converted to starch in leaves that is converted back during periods of darkness
• converted to sucrose and transported to other parts of the plant or to storage organs like seeds
• converted to starch or other forms of storage compounds at the storage organs that can be converted back to glucose
• reacts with nitrates and other mineral salts absorbed from the soil to form amino acids that are used to form proteins used for the synthesis of new protoplasm in leaves

Question 9

Why is photosynthesis important?

Answer 9

• photosynthesis makes chemical energy available to animals and other organisms
• photosynthesis removes carbon dioxide and provides oxygen
• energy is stored in fossil fuels through photosynthesis

Question 10

What is the structure of the lamina and how is it adapted for its function?

Answer 10

The lamina has a large flat surface area increasing the surface area to volume ratio enabling it to obtain the maximum amount of sunlight for photosynthesis,.
The lamina also is thin for the rapid diffusion of carbon dioxide into the inner cells of the leaf

Question 11

What is the structure of the petiole and how is it adapted for its function?

Answer 11

It holds the lamina away from the stem so that the lamina can obtain sufficient sunlight and air

Question 12

What are the functions of veins?

Answer 12

Veins carry water and mineral salts to the cells in the lamina and carry manufactured food from these cells to other parts of the plant