Photosynthesis

Question 1

What is the word equation for photosynthesis?

Answer 1

Carbon dioxide + water –(using sunlight and chlorophyll)–> oxygen + glucose

Question 2

What factors limit the rate of photosynthesis in plants?

Answer 2

• Carbon dioxide
• Water
• light energy
• temperature
• amount of chlorophyll
• pH of soil

Question 3

How do plants use the glucose that they make?

Answer 3

It is used for energy and to make cellulose (to build cell walls) and starch (food source).

Question 4

What extra materials do plant cells need to produce proteins?

Answer 4

Nitrates from the soil is needed to bond with glucose to make amino acids.

Question 5

What is a practical test for starch (in a plant)?

Answer 5

You can use an iodine test:
1. Boil the leaf of the plant in alcohol (to remove chlorophyll)
2. Put a few drops of iodine solution on it.
3. If it turns blue, starch is present.

Question 6

What is a practical test for sugar (in a plant)?

Answer 6

Use Benedict’s solution:
1. Add benedict’s solution to the plant
2. Heat in a water bath
3. If it turns orange-red then sugar is present

Question 7

What is a practical test for protein (in a plant)?

Answer 7

You use copper sulphate solution and sodium hydroxide solution:
1. Add the two solutions
2. If it turns purple then protein is present.

Question 8

What is a vertical farm?

Answer 8

A vertical farm is where you grow plants indoors in a controlled environment. They are generally in very tall buildings, to make the most of the space.

Question 9

What are the pros and cons of vertical farms?

Answer 9

Pros:
- save space
- faster harvests
- less travel for food
- more nutrition
- save resources
- better for environment
- more control
- no pests
- grow anything practically anywhere

Cons:
- high starting cost
- skilled maintenance needed
- Natural disaster could ruin everything
- pollination
- lack of jobs for traditional farmers

Question 10

How can humans manipulate the different limiting factors of photosynthesis to get the best plants?

Answer 10

CO2 - add a fan to circulate it
Water - computer regulate it
Light - use LED lights
Chlorophyll - add magnesium, nitrogen, manganese or iron.
pH - don’t use soil! use hydroponics instead
Temperature - have a temperature regulator