Plant Structure and Photosynthesis

Question 1

Provide an example of a plant organ

Answer 1

Plants are made of organs like stems, roots and leaves

Question 2

What tissue is contained in a plant leave?

Answer 2

1. Mesophyll tissue - this is where most of the photsythesis in a plant occurs
2. Xylem and Phloem tissue - they transport things like water, mineral ions and sucrose around the plant
3. Epidermal tissue - this covers the whole plant

Question 3

What is the Equation for Photosynthesis

Answer 3

Carbon dioxide + water - Sunlight - Glucose + Oxygen
————–
Chlorophyll

Question 4

What does photosynthesis produce?

Answer 4

Glucose - which is food for plants

Question 5

Where does photosynthesis happen?

Answer 5

Inside chloroplasts which is in the plants LEAVES.

Question 6

How does photosythesis happen?

Answer 6

1. Inside chloroplasts there’s a green substance called chlorophyll .
2. Chlorophyll absorbs sunlight and uses its energy to convert carbon dioxide (from ai) and water (from soil) into glucose.
3. Oxygen is also produced as a by-product.

Question 7

What three factors affect the rate of photosythesis?

Answer 7

The intensity of the Light.

The volume of CO2

The temperature

Question 8

At night what factor will limit photosythesis?

Answer 8

Light is the limiting factor

Question 9

In winter what is the limiting factor?

Answer 9

Temperature

Question 10

If its warm and bright enough what could be the factor that limits photosythesis

Answer 10

Amount of CO2 available.

Question 11

Describe an experiment to work out the ideal conditions for photosythesis?

Answer 11

Get a sealed glass and put some canadian pondweed in it and cover it with some water.

The top of the sealed glass vessel should be connected to a gas syringe.

The oxygen produced by the pondweed through photosythesesis is then collected by the gas syringe.

The greater the amount of oxygen the greater the rate of photosythensis

Question 12

Learn the 3 GRAPHS FOR RATE OF PHOTOSYTHESIS

Answer 12

GRAPH 1 - shows rate of photosythesis and light intensity

GRAPH 2 - shows rate of photosythesis and level of CO2

GRAPH 3 - shows rate of photosythesis and the temperature

Question 13

How does temperature impact upon the rate of photosythesis

Answer 13

Plant enzymes are neede for photosythesis

If the temperature s too cold the enzyes work more slowly.

If the plant gets too hot (around 45 c) the enzymes it needs for photosythesis and its other reactions will be damaged

Question 14

How do you test/experiment how each of the three factors impact upon photosythesis?

Answer 14

It’s not difficult but you must keep the other conditions (and the other two factors) constant so that any change in photosythesis is down to the factor you are testing.

Question 15

How do you creat the ideal conditions for farming?

Answer 15

1. Get a greenhouse.
2. Ensure greenhouse is ventilated in summer and there is a heater in the winter (for temperature)
3. Light is important so get artificial light for night time
4. Create carbon dixoide by using a paraffin heater as this by product is CO2
5. Ensure greenhouse isenclosed to keep pests and insects out

Question 16

Name 5 things that a plant can do with the glucose it produces through photosythesis

Answer 16

1. Respiration
2. Making cell walls
3. Making proteins
4. Stored in seeds
5. Stored as starch

Question 17

What happens when a plant respires?

Answer 17

Some of the glucose a plant creates from photosythesis is used for respiration.

This releases energy that enables tem to convert the rest of the glucose into various other useful substances that can be used to build new cells.

Question 18

How does a plant make proteins

Answer 18

Glucose is combined with nitrate ions (absorbed from the soil) to make AMINO ACIDS which are then made into proteins.

Question 19

How does a plant store glucose in seeds?

Answer 19

The glucose is turned into lipids (fats and oils) for storing in seeds.

Sunflower seeds contain a lot of oil.

Question 20

How does aplant store glucose as starch?

Answer 20

Glucose is turned into starch and stored in roots, stems and leaves.

This can be used fopr energy when photosythesis is not happening.

Starch is insoluable making it better for storing than glucose