Photosynthesis

Question 1

What is the waste product in photosynthesis?

Answer 1

Oxygen

Question 2

What happens to glucose in photosynthesis?

Answer 2

It is transported as soluble sugars but is stored as insoluble starch

Question 3

What can glucose and starch be converted to for?

Answer 3

Other substances in plants to be used for energy, growth and storage products

Question 4

Explain why plants grow faster in summer

Answer 4

More light and warmth

Question 5

What do plants carry out?

Answer 5

Respiration as well as photosynthesis

Question 6

Balanced symbol equation for photosynthesis

Answer 6

6CO₂ + 6H₂O ->C₆H₁₂O₆6O₂

Question 7

Describe the development of the understanding of the process of photosynthesis

Answer 7

• the view of Greek scientists that plants gained mass only by taking in minerals from the soil
• Van Helmont’s experimental conclusion that plant growth cannot be solely due to nutrients from the soil
• Priestly’s experiment which showed that oxygen is produced by plants

Question 8

Describe the conversion of glucose and starch to other substances in plants and their use

Answer 8

• glucose for energy (respiration)
• cellulose for cell walls
• proteins for growth and repair
• starch, fats and oils for storage

Question 9

Describe how photosynthesis can be increased

Answer 9

By providing more carbon dioxide, light and higher temperatures

Question 10

Explain why plants carry out respiration all the time

Answer 10

Because they need to supply their cells with energy they need to work, grow and reproduce

Question 11

Explain why insoluble substances such as starch are used for storage

Answer 11

• does nit move away in solution from storage areas

- does not affect water concentration inside cells

Question 12

Describe photosynthesis as a two stage process

Answer 12

• light energy is used to split water, releasing oxygen gas and hydrogen ions
• carbon dioxide gas combines with the hydrogen to make glucose

Question 13

Explain why plants take in carbon dioxide and give out oxygen during the day and do the reverse at nigh, in terms of both photosynthesis and respiration

Answer 13

Day - plants respire constantly, but they also photosynthesise at much greater rate, using up the carbon dioxide produced from respiration and giving out oxygen
Night - absence of light means that plants cannot photosynthesise p, but they continue to respire

Question 14

Explain the effects of limiting factors on the rate of photosynthesis

Answer 14

Carbon dioxide
Light
Temperature

Question 15

Word equation for photosynthesis

Answer 15

Carbon dioxide + water -> glucose + oxygen