· pdf filethe open academy page 1 forces easier (a) the diagram shows two forces acting on an...

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The Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object? Tick ( ) one box. 8 N to the right 8 N to the left 4 N to the right 4 N to the left (1) (b) BASE jumpers jump from very high buildings and mountains for sport. The diagram shows the forces acting on a BASE jumper in flight. The BASE jumper is wearing a wingsuit. (i) Draw a ring around the correct answer in the box to complete each sentence. smaller than The BASE jumper accelerates forwards when force A is equal to force B. bigger than

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Page 1: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 1

Forces Easier

(a) The diagram shows two forces acting on an object.

What is the resultant force acting on the object?

Tick ( ) one box.

8 N to the right

8 N to the left

4 N to the right

4 N to the left

(1)

(b) BASE jumpers jump from very high buildings and mountains for sport.

The diagram shows the forces acting on a BASE jumper in flight. The BASE jumper is wearing a wingsuit.

(i) Draw a ring around the correct answer in the box to complete each sentence.

smaller than

The BASE jumper accelerates forwards when force A is equal to force B.

bigger than

Page 2: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 2

smaller than

The BASE jumper falls with a constant speed when force C is equal to force D.

bigger than

(2)

(ii) To land safely the BASE jumper opens a parachute.

What effect does opening the parachute have on the speed of the falling BASE jumper?

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

Give a reason for your answer.

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

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

(Total 5 marks)

Page 3: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 3

Forces Harder

The diagram shows a boat pulling a water skier.

(a) The arrow represents the force on the water produced by the engine propeller. This force causes the boat to move.

Explain why.

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

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

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

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

(b) The boat accelerates at a constant rate in a straight line. This causes the velocity of the water skier to increase from 4.0 m/s to 16.0 m/s in 8.0 seconds.

(i) Calculate the acceleration of the water skier and give the unit.

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

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

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

Acceleration = .................................................. (3)

(ii) The water skier has a mass of 68 kg.

Calculate the resultant force acting on the water skier while accelerating.

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

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

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

Resultant force = .................................................. N (2)

Page 4: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 4

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

The force from the boat pulling the water skier forwards

less than

will be the same as the answer to part (b)(ii).

greater than

Give the reason for your answer.

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

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

(Total 9 marks)

Page 5: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 5

Forces Hardest

Figure 1 shows a skydiver training in an indoor wind tunnel.

Large fans below the skydiver blow air upwards.

Figure 1

(a) The skydiver is in a stationary position.

Complete the free body diagram for the skydiver.

(2)

(b) The skydiver now straightens his legs to increase his surface area.

This causes the skydiver to accelerate upwards.

Explain why straightening his legs cause the skydiver to accelerate upwards.

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

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

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

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

(c) A small aeroplane used for skydiving moves along a runway.

The aeroplane accelerates at 2 m / s2 from a velocity of 8 m / s.

After a distance of 209 m it reaches its take-off velocity.

Calculate the take-off velocity of the aeroplane.

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

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

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

Take-off velocity = .................................... m / s (3)

Page 6: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 6

(d) A skydiver jumps from an aeroplane.

There is a resultant vertical force of 300 N on the skydiver.

There is a horizontal force from the wind of 60 N.

Draw a vector diagram on Figure 2 to determine the magnitude and direction of the resultant force on the skydiver.

Figure 2

Magnitude of resultant force = ..................................... N (5)

(Total 12 marks)

Page 7: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 7

Energy Easier

The figure below shows a car with an electric motor.

The car is moving along a flat road.

(a) (i) Use the correct answers from the box to complete each sentence.

light electrical kinetic potential sound

The car’s motor transfers ............................................. energy

into useful ............................................. energy as the car moves.

Some energy is wasted as ............................................. energy. (3)

(ii) What happens to the wasted energy?

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

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

(b) The electric motor has an input energy of 50 000 joules each second.

The motor transfers 35 000 joules of useful energy each second.

Calculate the efficiency of the electric motor.

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

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

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

Efficiency = ............................................................... (2)

(Total 6 marks)

Page 8: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 8

Energy Harder

A student finds some information about energy-saving light bulbs.

(a) A 30W light bulb uses 600J of electrical energy in a certain period of time. In that time, it produces 450 J of light energy. The rest of the energy is wasted.

(i) Calculate the energy wasted by the light bulb in this period of time.

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

Wasted energy = ................................. J (1)

(ii) What happens to the energy wasted by the light bulb?

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

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

(iii) Calculate the efficiency of this light bulb.

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

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

Efficiency = ............................................................ (2)

(iv) Calculate the period of time, in seconds, during which the 600 J is provided to the 30 W light bulb.

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

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

Time = ......................... s (2)

Page 9: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 9

(b) A company that makes light bulbs provides information about some of their products.

The table shows some of this information.

Power in watts Lifetime in hours Cost of bulb in £

Filament bulb 60 1250 2.00

LED bulb 12 50 000 16.00

(i) Suggest why it is important to confirm this information independently.

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

(ii) A homeowner is thinking about replacing his filament bulbs with LED bulbs.

A 12 W LED bulb gives the same light output as a 60 W filament bulb.

Suggest reasons why the homeowner is likely to choose LED bulbs.

Use the information given in the table.

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

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

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

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

(iii) State one factor, other than efficiency, that is important when considering the choice of a bulb for lighting in the home.

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

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

(Total 10 marks)

Page 10: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 10

Energy Hardest

A homeowner had a new gas boiler installed.

(a) The following information is an extract from the information booklet supplied with the boiler.

Fuel Natural Gas

Water temperature 60 °C

Energy supplied to gas boiler

8.0 kJ/s (8.0 kW)

Efficiency 0.95

(i) Calculate the energy transferred each second by the gas boiler to the water inside the boiler.

Show clearly how you work out your answer.

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

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

Energy transferred by the gas boiler each second = ..................... kJ (2)

(ii) The energy value of the gas used in a home is measured in kilowatt-hours (kWh).

The homeowner has a pre-payment meter and pays £30 into his account. With a pre-payment meter, gas costs 15p per kilowatt-hour.

Calculate the total number of hours that the gas boiler would operate for £30.

Show clearly how you work out your answer.

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

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

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

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

Number of hours = .................................................. (2)

Page 11: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 11

(b) Although the gas boiler is very efficient, some energy is wasted.

Explain what happens to the waste energy.

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

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

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

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

(Total 6 marks)

Page 12: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 12

Bonding Easiest

The structures of four substances, A, B, C and D, are represented in Figure 1.

(a) Use the correct letter, A, B, C or D, to answer each question.

(i) Which substance is a gas?

(1)

(ii) Which substance is a liquid?

(1)

(iii) Which substance is an element?

(1)

(iv) Which substance is made of ions?

(1)

(b) Figure 2 shows the bonding in substance C.

Page 13: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 13

(i) What is the formula of substance C?

Draw a ring around the correct answer.

SO2 SO2 S2O

(1)

(ii) Use the correct answer from the box to complete the sentence.

delocalised shared transferred

When a sulfur atom and an oxygen atom bond to produce substance C,

electrons are ......................................................................................... (1)

(iii) What is the type of bonding in substance C?

Draw a ring around the correct answer.

covalent ionic metallic

(1) (Total 7 marks)

Page 14: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 14

Bonding Harder

(a) Write a balanced symbol equation for the reaction between magnesium (Mg) and oxygen (O2) to form magnesium oxide (MgO).

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

(b) The diagram shows the electronic structure of a magnesium atom. The atomic (proton) number of magnesium is 12.

Magnesium atom

Draw a similar diagram to show the electronic structure of an oxygen atom. The atomic (proton) number of oxygen is 8.

(1)

(c) Magnesium ions and oxide ions are formed when magnesium reacts with oxygen.

The diagram shows the electronic structure of an oxide ion.

Oxide ion

Draw a similar diagram to show the electronic structure of a magnesium ion.

(1)

Page 15: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

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(d) Magnesium oxide is a white solid with a high melting point.

Explain how the ions are held together in solid magnesium oxide.

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

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

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

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

(e) Indigestion tablets can be made from magnesium oxide. The magnesium oxide neutralises some of the hydrochloric acid in the stomach.

Complete the word equation for the reaction between magnesium oxide and hydrochloric acid.

hydrochloric acid + magnesium oxide → ...................... + water. (1)

(Total 6 marks)

Page 16: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

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Bonding Hardest Glass is made from silicon dioxide.

© Velirina/iStock/Thinkstock

(a) Silicon dioxide has a very high melting point.

Other substances are added to silicon dioxide to make glass. Glass melts at a lower temperature than silicon dioxide.

Suggest why.

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

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

(b) Sodium oxide is one of the substances added to silicon dioxide to make glass.

(i) Sodium oxide contains Na+ ions and O2– ions.

Give the formula of sodium oxide.

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

(ii) Sodium oxide is made by heating sodium metal in oxygen gas.

Complete the diagram to show the outer electrons in an oxygen molecule (O2).

Page 17: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

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(2)

(c) Glass can be coloured using tiny particles of gold. Gold is a metal.

Describe the structure of a metal.

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

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

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

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

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

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

(Total 7 marks)

Page 18: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 18

Atoms Easiest The figure below shows an atom of boron.

(a) When the mass of the boron atom is calculated, the mass of the electrons is ignored.

Why is the mass of the electrons ignored?

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

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

(b) How many electrons are there in the boron atom?

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

(c) What is the electrical charge on the nucleus of the boron atom?

Tick one box.

+1

+5

+6

+11

(1)

Page 19: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

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(d) The mass number of boron is 11.

Use the figure above to calculate the number of neutrons in the nucleus of the boron atom.

Explain how you worked out the answer.

Number of neutrons = ....................................................................................

Explanation ....................................................................................................

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

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

(e) Phosphorus has a mass number of 31 and has 16 neutrons.

What percentage of the mass number of phosphorus is the number of neutrons?

Give your answer to two significant figures.

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

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

Percentage = ....................................... (2)

(Total 8 marks)

Page 20: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 20

Atoms Harder

This question is about atomic structure and elements.

(a) Complete the sentences.

(i) The atomic number of an atom is the number of .................................. (1)

(ii) The mass number of an atom is the number of ....................................

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

(b) Explain why an atom has no overall charge.

Use the relative electrical charges of sub-atomic particles in your explanation.

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

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

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

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

(c) Explain why fluorine and chlorine are in the same group of the periodic table.

Give the electronic structures of fluorine and chlorine in your explanation.

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

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

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

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

Page 21: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

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(d) The diagram shows the electronic structure of an atom of a non-metal.

What is the chemical symbol of this non-metal?

Tick ( ) one box.

Ar

O

S

Si

(1)

(e) When elements react, their atoms join with other atoms to form compounds.

Complete the sentences.

(i) Compounds formed when non-metals react with metals consist of

particles called .................................................. . (1)

(ii) Compounds formed from only non-metals consist of

particles called ........................................ . (1)

(Total 9 marks)

Page 22: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 22

Atoms Hardest

Fluorine is more reactive than chlorine. Fluorine reacts with most elements in the Periodic Table. However, fluorine does not react with argon.

Atomic numbers: F 9; Cl 17; Ar 18.

(a) To which group of the Periodic Table do fluorine and chlorine belong?

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

(b) (i) Give one use for argon.

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

(ii) Explain why the noble gas argon is unreactive.

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

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

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

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

(c) (i) Give one use for chlorine.

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

(ii) Draw the electron arrangement of a chlorine atom.

Page 23: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

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(2)

(iii) Explain why fluorine is more reactive than chlorine.

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

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

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

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

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

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

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

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

(Total 10 marks)

Page 24: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 24

Cells Easiest

Substances can move into cells and out of cells.

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

Water moves into cells and out of cells by

active transport.

osmosis.

reabsorption.

freely permeable

The water moves through a non-permeable membrane.

partially permeable

(2)

(b) Students put plant cells into two different strengths of sugar solutions, A and B.

The diagram below shows what the cells looked like after 1 hour.

Cell in sugar solution A

(after 1 hour)

Cell in sugar solution B

(after 1 hour)

(i) Describe two ways in which the cell in sugar solution B is different from the cell in sugar solution A.

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

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

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

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

Page 25: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

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(ii) A student put red blood cells into water.

Suggest what would happen to the cells.

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

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

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

(c) In the human body, glucose is absorbed into the blood from the small intestine.

The small intestine contains many villi.

Which two of the following help the absorption of glucose in the small intestine?

Tick ( ) two boxes.

Villi have a cell wall.

Villi are covered in thick mucus.

Villi give the small intestine a large surface area.

Villi have many blood capillaries.

(2) (Total 7 marks)

Page 26: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 26

Cells Harder

The image below shows an epithelial cell from the lining of the small intestine.

(a) (i) In the image above, the part of the cell labelled A contains chromosomes.

What is the name of part A?

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

(ii) How are most soluble food molecules absorbed into the epithelial cells of the small intestine?

Draw a ring around the correct answer.

diffusion osmosis respiration

(1)

(b) Suggest how the highly folded cell surface helps the epithelial cell to absorb soluble food.

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

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

Page 27: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

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(c) Epithelial cells also carry out active transport.

(i) Name one food molecule absorbed into epithelial cells by active transport.

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

(ii) Why is it necessary to absorb some food molecules by active transport?

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

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

(ii) Suggest why epithelial cells have many mitochondria.

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

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

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

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

(d) Some plants also carry out active transport.

Give one substance that plants absorb by active transport.

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

(Total 8 marks)

Page 28: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

Page 28

Cells Hardest

The figure below shows four different types of cell.

(a) Which cell is a plant cell?

Give one reason for your answer.

Cell ..................

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

(b) Which cell is an animal cell?

Give one reason for your answer.

Cell ..................

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

(c) Which cell is a prokaryotic cell?

Give one reason for your answer.

Cell ..................

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

Page 29: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

The Open Academy

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(d) A scientist observed a cell using an electron microscope.

The size of the image was 25 mm.

The magnification was × 100 000

Calculate the real size of the cell.

Use the equation:

Give your answer in micrometres.

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

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

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

Real size = .................................... micrometres (3)

(Total 9 marks)

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The Open Academy

Page 30

Respiration and Photosynthesis Easiest

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)

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(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

(2) (Total 9 marks)

Page 32: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

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Respiration and Photosynthesis Harder

This question is about photosynthesis.

(a) Plants make glucose during photosynthesis. Some of the glucose is changed into insoluble starch.

What happens to this starch?

Tick ( ) one box.

The starch is converted into oxygen.

The starch is stored for use later.

The starch is used to make the leaf green. (1)

(b) A student investigated the effect of temperature on the rate of photosynthesis in pondweed.

The diagram shows the way the experiment was set up.

(i) The student needed to control some variables to make the investigation fair.

State two variables the student needed to control in this investigation.

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

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

Page 33: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

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(ii) The bubbles of gas are only produced while photosynthesis is taking place.

What two measurements would the student make to calculate the rate of photosynthesis?

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

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

(c) The graph shows the effect of temperature on the rate of photosynthesis in the pondweed.

Temperature in °C

(i) Name the factor that limits the rate of photosynthesis between the points labelled A and B on the graph.

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

(ii) Suggest which factor, carbon dioxide, oxygen or water, might limit the rate of photosynthesis between the points labelled C and D on the graph.

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

(Total 7 marks)

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Respiration and Photosynthesis Hardest Students investigated the effect of changing the carbon dioxide concentration on the rate of photosynthesis in pieces of leaf.

Diagram 1 shows the type of leaf used by the students.

The students:

• cut pieces of leaf from the green region

• put the pieces into tubes

• added different concentrations of carbon dioxide to each tube

• shone lights on the tubes with either high or low light intensity

• recorded the concentration of oxygen in the tubes after 5 hours.

Diagram 2 shows how each experiment was set up.

The graph shows the results of the investigation.

Page 35: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

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(a) (i) Describe the effect of increasing carbon dioxide concentration on the rate of photosynthesis at low light intensity.

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

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

(ii) Explain the effect that you have described.

In your answer you should refer to limiting factors.

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

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

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

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

(b) What would have been the effect on oxygen concentration over the five-hour period if a white region of the leaf had been used, instead of a green region?

Effect .............................................................................................................

Explain your answer.

Explanation ....................................................................................................

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

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

Page 36: · PDF fileThe Open Academy Page 1 Forces Easier (a) The diagram shows two forces acting on an object. What is the resultant force acting on the object?

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(c) Some people keep indoor plants which have variegated leaves (leaves with green and white regions).

If plants with variegated leaves are kept in dim light conditions the white areas of the leaves start to turn green.

This is an advantage to the plant.

Suggest why.

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

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

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

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

(Total 7 marks)