(a)€€€€Complete the equation for photosynthesis.

[Pages:13]1 (a) Complete the equation for photosynthesis.

.............................. + water

.............................. + .............................. (3)

(b) The rate of photosynthesis in a plant depends on several factors in the environment. These factors include light intensity and the availability of water.

Describe and explain the effects of two other factors that affect the rate of photosynthesis.

You may include one or more sketch graphs in your answer.

........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................

(5) (Total 8 marks)

Page 1 of 13

2 Photosynthesis uses carbon dioxide to make glucose.

(a) (i) Complete the equation for photosynthesis.

carbon dioxide + ..........................

glucose + ....................

(2)

(ii) What type of energy does a plant use in photosynthesis?

............................................................................................................... (1)

(iii) Which part of a plant cell absorbs the energy needed for photosynthesis?

............................................................................................................... (1)

(b) The graph shows the effect of the concentration of carbon dioxide on the rate of photosynthesis in tomato plants at 20 ?C.

(i) What is the maximum rate of photosynthesis of the tomato plants shown in the graph? .......................... arbitrary units (1)

(ii) At point X, carbon dioxide is not a limiting factor of photosynthesis. Suggest one factor that is limiting the rate of photosynthesis at point X. ............................................................................................................... (1)

Page 2 of 13

(c) A farmer plans to grow tomatoes in a large greenhouse. The concentration of carbon dioxide in the atmosphere is 0.04%. The farmer adds carbon dioxide to the greenhouse so that its concentration is 0.08%. (i) Why does the farmer use 0.08% carbon dioxide? Tick ( ) one box.

To increase the rate of growth of the tomato plants

To increase the rate of respiration of the tomato plants

To increase water uptake by the tomato plants

(1) (ii) Why does the farmer not use a concentration of carbon dioxide higher than 0.08%?

Tick ( ) two boxes.

Because it would cost more money than using 0.08%

Because it would decrease the temperature of the greenhouse

Because it would not increase the rate of photosynthesis of the tomato plants any further

Because it would increase water loss from the tomato plants

3 (a) Complete the word equation for photosynthesis.

carbon dioxide + water

energy

(2) (Total 9 marks)

glucose + ..................................... (1)

Page 3 of 13

(b) Draw a ring around the correct answer to complete each sentence.

light. (i) The energy needed for photosynthesis comes from osmosis.

respiration. (1)

chloride. (ii) Energy is absorbed by a green pigment called chloroplast.

chlorophyll. (1)

(iii) If the temperature is decreased the rate of photosynthesis will

decrease. increase. stay the same.

(1)

(c) Give three ways in which plants use the glucose made in photosynthesis.

1 .....................................................................................................................

........................................................................................................................

2 .....................................................................................................................

........................................................................................................................

3 .....................................................................................................................

........................................................................................................................

(3) (Total 7 marks)

4 Green plants can make glucose.

(a) Plants need energy to make glucose.

How do plants get this energy?

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (2)

Page 4 of 13

(b) Plants can use the glucose they have made to supply them with energy. Give four other ways in which plants use the glucose they have made. ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................

5 Plants absorb light to photosynthesise.

(a) What is the correct word equation for photosynthesis? Tick one box.

(4) (Total 6 marks)

carbon dioxide + glucose

oxygen + water

glucose + oxygen

carbon dioxide + water

oxygen + water

carbon dioxide + glucose

water + carbon dioxide

oxygen + glucose

(1)

Page 5 of 13

(b) Figure 1 shows some of the apparatus that can be used to measure the rate of photosynthesis. Figure 1

The rate of photosynthesis in the pondweed is affected by different colours of light. Describe a method you could use to investigate this. You should include: ? what you would measure ? variables you would control. ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................ ........................................................................................................................

(6)

Page 6 of 13

(c) A scientist carried out a similar investigation. Her results are shown in Figure 2. Figure 2

The scientist said:

`Light stops being a limiting factor at a light intensity of 20 units.'

Give evidence from Figure 2 to support this statement.

........................................................................................................................

........................................................................................................................ (1)

(d) What could be limiting the rate of photosynthesis at a light intensity of 25 units?

Give one factor.

........................................................................................................................

(1) (Total 9 marks)

Page 7 of 13

6

A group of pupils investigated the way in which the colour of light affects photosynthesis.

The pupils:

? put a piece of pondweed into a test tube of water

? shone light from a lamp with a red light bulb onto the pondweed

? counted the bubbles of gas produced by the pondweed every minute for three minutes.

The diagram shows the experiment.

The pupils repeated their experiment using a yellow light bulb, a green light bulb and a blue light bulb. (a) (i) What was the independent variable in the investigation?

............................................................................................................... (1)

(ii) To make the investigation fair the pupils needed to control some variables. Suggest one variable that the pupils should have controlled during their investigation. ............................................................................................................... (1)

(iii) It is better to count the bubbles every minute for three minutes than to count all the bubbles in three minutes. Why? ............................................................................................................... ............................................................................................................... (1)

Page 8 of 13

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download