Chapter 7: Nutrition In Plants

Question 1

What is the word equation for photosynthesis?

Answer 1

Water + carbon dioxide —> Glucose + oxygen
(light above, chlorophyll below)

Question 2

Describe the graph of light intensity (Limiting factor)

Answer 2

1) Light intensity is a limiting factor for photosynthesis
2) Light intensity is not a limiting factor for photosynthesis

Question 3

Describe the graph of carbon dioxide concentration (limiting factor)

Answer 3

1) Carbon dioxide is a limiting factor for photosynthesis
2) Carbon dioxide is not a limiting factor for photosynthesis

Question 4

Describe the arrangement of the plant

Answer 4

The leaves are arranged in a regular pattern around the stem so that leaves are not blocking each other and that each and every leaf receives maximum amount of sunlight

Question 5

Describe the lamina in the plant

Answer 5

It has a large surface area for maximum absorption of sunlight and thin to allow rapid diffusion of carbon dioxide into the lead

Question 6

Explain the petiole

Answer 6

It positions the leaf away from the stem to allow maximum absorption of sunlight and carbon dioxide

Question 7

Explain the veins

Answer 7

It is a network of veins branching out from the vein in the mid-in
It allows transport of water and mineral salts to the leaves as well as the transport of manufactured food away from the leaves

Question 8

Explain why there is a waxy cuticle on the upper and lower epidermis

Answer 8

To reduce water loss through evaporation from the leaf

Question 9

Explain why the cuticle is transparent

Answer 9

To aloow light enter into the leaf

Question 10

Explain why the mesophyll cells contains chlorophyll

Answer 10

So that light energy can be converted to chemical energy used in the manufacture of sugars

Question 11

Explain why the stomata are present in the epidermal layers

Answer 11

It opens in the presence of light whch allows carbon dioxide to diffuse in and oxygen to diffuse out

Question 12

Explain why there are more chloroplast in the palisade tissue

Answer 12

So that more light energy is absorbed

Question 13

Explain the interconnecting system of air spaces in the spongy mesophyll

Answer 13

To allow rapid diffusion of carbon dioxide and oxygen into and out of mesophyll cells

Question 14

Explain the veins containing the xylem and phloem situated close to the mesophyll cells

Answer 14

• The xylem transport water and mineral salts to the leaves
• The phloem transport sugars away from the leaf

Question 15

Explain what happens to glucose formed during photosynthesis

Answer 15

1) Used immediately for cellular respiration to provide energy for cellular activities
2) Excess glucose is converted to starch and stored in the leaves. In the darkness, starch is converted to glucose by enzymes

Question 16

Explain the importance of photosynthesis

Answer 16

1) Oxygen produced during photosynthesis is needed by other organisms for respiration
2) Green plants can transform light energy into chemical energy. This energy is passed to other organisms in the food chains