Photosynthesis

Question 1

What is the equation for photosynthesis

Answer 1

Light
Carbon dioxide + water ———-—> glucose + oxygen
Chlorophyll

Question 2

What is photosynthesis

Answer 2

the process by which plants and some other organisms convert light energy into chemical energy in the form of glucose

Question 3

Where does photosynthesis take place

Answer 3

Inside chloroplasts found in plants and algae

Question 4

What are the 4 key factors that affect the rate of photosynthesis

Answer 4

Temperature, light intensity, carbon dioxide concentration, chlorophyll concentration

Question 5

How does chlorophyll concentration affect the rate of photosynthesis

Answer 5

High chlorophyll concentration gives a high rate of photosynthesis

Question 6

How does carbon dioxide concentration affect the rate of photosynthesis

Answer 6

Increasing the carbon dioxide concentration increases the rate of photosynthesis because carbon dioxide is a reactant in photosynthesis

Question 7

How does light intensity affect the rate of photosynthesis

Answer 7

A greater light intensity means a greater rate of photosynthesis because more energy is being provided

Question 8

How does temperature affect the rate of photosynthesis

Answer 8

Increasing the temperature increases the rate of photosynthesis because more energy is being provided

Question 9

What is the balanced symbol equation for photosynthesis

Answer 9

6CO2 + 6H20 ———> C6H12O6 + 602

Question 10

What is the purpose of the stem

Answer 10

To transport water

Question 11

What is the purpose of roots

Answer 11

To absorb water and nutrients and to anchor plant

Question 12

What is the purpose of leaves

Answer 12

Photosynthesis

Question 13

Why is photosynthesis an endothermic reaction

Answer 13

Because light energy is absorbed to make glucose

Question 14

Why is photosynthesis essential for other organisms

Answer 14

Because oxygen is needed for other organisms to carry out aerobic respiration and glucose forms the basis of all food chains, providing chemical energy sustaining all life on earth

Question 15

What is the starch method for testing for photosynthesis

Answer 15

The starch method involves testing for the presence of starch in a leaf after it has undergone photosynthesis.
First the leaf is boiled to remove any pigments.
Then it is placed in alcohol to remove chlorophyll. After that, the leaf is soaked in an iodine solution.
If starch is present, the leaf will turn blue- black, indicating successful photosynthesis.

Question 16

How can you test for photosynthesis using bicarbonate indicator

Answer 16

You use a bicarbonate indicator solution that changes colour based on pH level, which is affected by the presence of carbon dioxide. As the plant undergoes photosynthesis it consumes carbon dioxide from the water causing the pH to increase

Question 17

How can you see photosynthesis using oxygen

Answer 17

You use an aquatic plant and place it in water under a light source, as the plant undergoes photosynthesis, it will release oxygen bubbles into the water, you can collect these bubbles in an inverted test tube and the volume of oxygen collected shows the rate of photosynthesis

Question 18

What is an independent variable

Answer 18

An independent variable is what you change in an experiment

Question 19

What is a dependent variable

Answer 19

The variable being measure in an experiment

Question 20

What is a control variable

Answer 20

The factor that stays the same throughout the experiment

Question 21

Why do plants change colour in iodine solution

Answer 21

Because the solution reacts with starch to form a blue-black colour. During photosynthesis plants convert carbon dioxide and water into glucose which is then stored as starch, when a plant is placed in iodine solution a chemical reaction occurs with the starch in the leaf turning it blue-black

Question 22

At what temperature do the enzymes get denatured causing photosynthesis reaction to stop completely

Answer 22

40-50 degrees celsius

Question 23

How do farmers optimise plant growth

Answer 23

Farmers want to increase the rate of photosynthesis as much as possible to improve plant growth. This is done by optimising the growing conditions so that the plants grow faster, fruit earlier and give higher yields (quantity of product collected)

Question 24

What is the easiest way to increase the rate of photosynthesis for farmers

Answer 24

To use plastic poly tunnels to cover the crops in the fields, these keep the plants warmer, increasing the rate of photosynthesis

Question 25

What is the more sophisticated way to maximise plant growth

Answer 25

Full glass greenhouses, they can also be given extra light, heat and carbon dioxide and raise the values of all the possible limiting factors ( electric lights and gas burners)

Question 26

What is an addition to greenhouses that help maximise plant growth

Answer 26

Hydroponics, this is a system where the roots of the plant rest in oxygenated water with a carefully controlled balance of mineral ions to optimise growth

Question 27

What is one of the most important nutrients that a plant needs from the soil

Answer 27

Nitrates, these are necessary to build amino acids to form proteins for the growth of a plant

Question 28

How do farmers optimise the amount of nitrates in the soil

Answer 28

Farmers add fertilisers that contain these nitrates to the soil to maximise growth

Question 29

What must farmers consider when choosing which method to use to maximise plant growth

Answer 29

Farmers must balance the cost of maximising each condition for plant growth with their increased profit from selling the crop

Question 30

What is the function of glucose

Answer 30

Glucose provides energy for growth, and supports cell structure by forming cellulose