Plants and Photosynthesis (B2)

Question 1

How is the leaf structure adapted for photosynthesis?

Answer 1

Adaption Purpose
Large surface area: To absorb more light
Thin: Short distance for carbon dioxide to diffuse into leaf cells
Chlorophyll: Absorbs sunlight to transfer energy into chemicals
Network of veins: To support the leaf and transport water and carbohydrates
Stomata: Allow carbon dioxide to diffuse into the leaf

Question 2

What is the word equation for photosynthesis?

Answer 2

carbon dioxide + water —> glucose + oxygen + water.

Question 3

What is the by-product of photosynthesis?

Answer 3

Oxygen

Question 4

What are the limiting factors of photosynthesis?

Answer 4

Light intensity, carbon dioxide concentration and temperature. Without enough light, a plant cannot photosynthesise very quickly, even if there is plenty of water and carbon dioxide.

Question 5

How do plants use glucose?

Answer 5

The glucose made in photosynthesis is transported around the plant as soluble sugars. Glucose is used in respiration to release energy for use by the plant’s cells. However, glucose is converted into insoluble substances for storage.

Question 6

How can we artificially create the ideal conditions for farming?

Answer 6

In greenhouses, where the conditions are more easily controlled than in the open air outside:

The use of artificial light allows photosynthesis to continue beyond daylight hours. Bright lights also provide a higher-than-normal light intensity.

The use of artificial heating allows photosynthesis to continue at an increased rate.

The use of additional carbon dioxide released into the atmosphere inside the greenhouse also allows photosynthesis to continue at an increased rate.