Topic 6: Plant nutrition

Question 1

What is photosynthesis? -

Answer 1

The process by which plants synthesize carbohydrates from raw materials using energy from light.

Question 2

What is the word equation for photosynthesis? -

Answer 2

Carbon dioxide + water → glucose + oxygen (in the presence of light and chlorophyll).

Question 3

What is the balanced symbol equation for photosynthesis? -

Answer 3

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.

Question 4

Where is chlorophyll found? -

Answer 4

In chloroplasts.

Question 5

What does chlorophyll do in photosynthesis? -

Answer 5

Transfers energy from light into chemical energy for the synthesis of carbohydrates.

Question 6

What are the subsequent uses and storage of carbohydrates made in photosynthesis? -

Answer 6

(a) Starch as an energy store

Question 7

Why are nitrate ions important for plants? -

Answer 7

For making amino acids.

Question 8

Why are magnesium ions important for plants? -

Answer 8

For making chlorophyll.

Question 9

How do you investigate the need for chlorophyll

Answer 9

light

Question 10

How do you investigate the need for light in photosynthesis? -

Answer 10

Cover part of a leaf with foil

Question 11

How do you investigate the need for carbon dioxide in photosynthesis? -

Answer 11

Place a plant in a bell jar with soda lime

Question 12

What is a limiting factor? -

Answer 12

A factor that is in short supply and restricts life processes.

Question 13

How does light intensity affect the rate of photosynthesis? -

Answer 13

As light intensity increases

Question 14

How does carbon dioxide concentration affect the rate of photosynthesis? -

Answer 14

As carbon dioxide concentration increases

Question 15

How does temperature affect the rate of photosynthesis? -

Answer 15

As temperature increases

Question 16

What happens to gas exchange in light and dark conditions? -

Answer 16

In light

Question 17

Why do leaves have a waxy cuticle? -

Answer 17

To reduce water loss.

Question 18

Why do leaves have a transparent epidermis? -

Answer 18

To protect internal tissues and allow light to pass to the palisade mesophyll.

Question 19

Why do leaves have a large surface area? -

Answer 19

To carry out photosynthesis.

Question 20

What are stomata used for in leaves? -

Answer 20

To allow gas exchange.

Question 21

Why does the lower epidermis of a leaf contain stomata? -

Answer 21

To protect internal tissues and contain stomata.

Question 22

What is the role of guard cells in a leaf? -

Answer 22

To control the opening and closing of stomata.

Question 23

What are the functions of air spaces in leaves? -

Answer 23

To allow gas exchange.

Question 24

What is the role of xylem in leaves? -

Answer 24

To transport water and minerals.

Question 25

What is the role of phloem in leaves? -

Answer 25

To transport sugars.

Question 26

How is the leaf adapted for photosynthesis? -

Answer 26

Large surface area

Question 27

What is the function of chloroplasts in photosynthesis? -

Answer 27

To absorb light energy and convert it into chemical energy.

Question 28

Why is carbon dioxide important in photosynthesis? -

Answer 28

It is a raw material that is fixed into glucose.

Question 29

Why is water important in photosynthesis? -

Answer 29

It is a raw material that is split to release oxygen.

Question 30

How is glucose used in plants after photosynthesis? -

Answer 30

Used in respiration

Question 31

What is starch used for in plants? -

Answer 31

Energy store.

Question 32

What is cellulose used for in plants? -

Answer 32

To build cell walls.

Question 33

What is sucrose used for in plants? -

Answer 33

For transport in the phloem.

Question 34

What is nectar used for in plants? -

Answer 34

To attract insects for pollination.

Question 35

How can you measure the rate of photosynthesis? -

Answer 35

By counting the number of oxygen bubbles produced by an aquatic plant.

Question 36

How does temperature affect photosynthesis rate? -

Answer 36

Higher temperatures increase enzyme activity until enzymes denature.

Question 37

How can you control the rate of photosynthesis? -

Answer 37

By controlling temperature

Question 38

Why do leaves have a large surface area and are thin? -

Answer 38

To maximize light absorption and gas exchange for photosynthesis.