Year 7 ScienceName:Science Teacher:The year 7 topics you are to be assessed are on

Electromagnetism & MagnetismHeathEnergyEcology

Magnets & Electromagnets

1. A pupil does four experiments with bar magnets and small, unmagnetised iron bars.She places them as shown below. For each experiment, tick one box to show the effect of the magnetic force between the two objects.

iron bar iron bar

they attract

they repel

no effect

experim ent A

iron bar bar m agnet

they attract

they repel

no e ffect

experim ent B

S N

bar m agnet bar m agnet

they a ttract

they repel

no e ffect

experim en t C

S NSN

iron bar bar m agnet

they attract

they repel

no e ffect

experim ent D

S

N

4 marks

2. The drawing shows a toy shark. Magnets X and Y make the shark ‘float’above the plastic base.

(a) On magnet X, write the letters N and S to label the poles of the magnet.1 mark

(b) (i) Choose a word from the list below to complete the sentence.

attract cancel repel

The toy shark ‘floats’ because the magnets ............................................... each

other.

1 mark

(ii) Sophie pressed down on the tail of the shark with her finger.

What happened to the shark when she removed her finger?

......................................................................................................................1 mark

(c) Sophie added weights to the toy shark and measured the distance between the two magnets.Her results are shown below.

weight added to the toy shark (N)

distance between the magnets (mm)

0.1 6

0.2 4

0.3 3

Complete the sentence below.

As the weight on the toy shark increased, the distance between the

magnets .......................................

1 mark

(d) Sophie turned the magnet in the plastic base the other way up.

What happened to the shark?

...............................................................................................................................1 mark

maximum 5 marks

3. A pupil wound a coil of copper wire around a glass tube and connected the wire to a battery. She placed a compass at each end of the tube and one compass beside the tube as shown.

X

Yglass tube

(a) (i) Complete the diagram by drawing arrows in compasses X and Y to show the direction of the magnetic field.

2 marks

(ii) Draw an arrow in the middle of the glass tube to show the direction of the magnetic field in the glass tube.

1 mark

(iii) When the switch is opened, in which direction will the three compass needles point?

...................................................................1 mark

(b) Give one way to reverse the magnetic field around the glass tube

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

.........................................................................................................................1 mark

(c) Two pieces of iron are placed inside the glass tube.

(i) When the switch is closed, the magnetic field is the same as in thediagram opposite. The pieces of iron become magnetised.Label the four poles on the pieces of iron.

glass tube

1 mark’(ii) When the switch was closed, the pieces of iron moved.

Explain why they moved.

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

.................................................................................................................1 mark

Maximum 7 marks

Ecology

1. The drawings show six living things.They spend all or part of the time in water.

not to scale

Look at the drawings.

(a) (i) Give the letter of one living thing that uses gills to take in oxygen.

..................1 mark(ii) Give the letter of one living thing that is covered in scales.

..................1 mark

(b) Use a word from the list below to fill the gap in the sentence.

lungs legs eyes backbones

The trout, duck, crocodile, water vole and frog are all called vertebrates because

they have ........................................

1 mark

(c) The trout spends all of its time in water.

Give one way the trout is suited for moving in water.

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

...............................................................................................................................1 mark

(d) Draw a line from each animal below to the group it belongs to.Draw only three lines.

animal group

frog

crocodile

water vo le

reptiles

m am m als

am phib ians

2 marks

maximum 6 marks

2. Copper and arsenic are present in the soil near copper mines.When earthworms eat this soil they change from brown to bright yellow.The copper and arsenic are not poisonous to earthworms.

(a) Earthworms are part of the food chain shown below.

not to scale

(i) Use the food chain to suggest how copper and arsenic get into the body of a sparrowhawk.

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

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

......................................................................................................................1 mark

(ii) Mary suggested that blackbirds are more likely to catch bright yellow

earthworms than brown earthworms.

Give one reason why this might be true.

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

......................................................................................................................1 mark

(b) Mary wanted to count the bright yellow earthworms and the brown earthworms in the soil at different distances from the mines.

What important information about the soil could she get from her results?

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

...............................................................................................................................1 markThe drawings below show an earthworm and three other worms.

not to scale

The ragworm belongs to the same group as the earthworm.

How can you tell this from the drawings?

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

...............................................................................................................................1 mark

(d) The roundworm and some flatworms are parasites.

What does this mean?Tick the correct box.

They feed only on insects. They live in a burrow.

They feed on other living things and harm them. They live in the sea.

1 mark

maximum 5 marks

3. Pyramids of numbers represent the numbers of organisms at each stage in a food chain.

Study the four pyramids of numbers A, B, C and D shown below.

A

C

B

D

(a) For each of the food chains choose the pyramid of numbers which best represents the food chain.

(i) grass insects spiders birds ........................1 mark

(ii) oak trees aphids blue tits sparrow hawks ........................1 mark

(iii) grass rabbits foxes fleas ........................1 mark

(b) (i) Which is the main process transferring energy to the surroundings at each stage in a food chain?

Tick the correct box.

growth

nutrition

reproduction

respiration1 mark

(ii) Which process transfers energy from organisms at one stage in a food chain to organisms at the next?

Tick the correct box.

reproduction

feeding

movement

photosynthesis1 mark

Maximum 5 marks

4. A pupil studied the organisms in a pond.

From her observations she drew this simple food web.

perch

sm all fish

w ater fleas

w a te r boatm en

tadpo les

m icroscopic plan ts

(a) Use only the information in the food web to answer the following.

(i) Write down one food chain from this food web. There should be four organisms in the food chain.

.......................... .......................... .......................... ...........................1 mark

(ii) Write down the producer in the food web.

..............................................................................................................1 mark

(b) Disease suddenly kills all the small fish. Complete the sentence to explain what is likely to happen to the number of water boatmen.

The number of water boatmen is likely to .....................................................

because ........................................................................................................

......................................................................................................................2 marks

Maximum 4 marks

5. Bats are mammals that can fly. In many parts of the world bats live in caves. Many other animals live in the caves and some feed on bat droppings. Bats fly out of the caves at night to catch insects.

The diagram shows part of a food web which includes the organisms living in a cave.

fleas

harvestm e n cave spiders bats

beetles m illipedes spring tails flies m oths

bat dropp ings inthe cave

flow ering p lan tsgrow ing ou ts ide

the cave

(a) In summer, birds enter the caves and eat large numbers of beetles.Suggest why this might cause the population of millipedes to:

(i) go up;

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

.................................................................................................................1 mark

(ii) go down.

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

.................................................................................................................1 mark

(b) In the space below, draw a pyramid of numbers for the following food chain.

flowering plants moths bats fleas

1 mark

Maximum 3 marks

Pathogens

1. The thermometer drawn below can be used to measure the temperature of the human body.

(a) (i) What is the lowest temperature this thermometer can measure?

..............°C1 mark

(ii) What is the normal temperature of the human body?Tick the correct box.

37ºC 39ºC 41ºC

1 mark

(iii) When we are ill our temperature may go up.

A nurse can measure a child’s temperature with two different thermometers as shown below.

Give one reason why it is safer to use a plastic strip thermometer than a glass thermometer.

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

......................................................................................................................1 mark

(b) Viruses are micro-organisms that can make us ill.

Give the name of one other type of micro-organism that can make us ill.

................................................................1 mark

(c) Alcohol and mercury are two liquids that can be used in glass thermometers.The table gives information about these liquids.

liquid boiling point (ºC) colour

alcohol 78 colourless

mercury 357 shiny grey

(i) A red dye is added to the colourless alcohol used in thermometers.Suggest a reason for this.

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

......................................................................................................................1 mark

(ii) Choose words from the list below to fill the gaps in the sentences.

gas liquid solid

When alcohol and mercury boil they both change from a liquid to

a ......................................

1 mark

A thermometer containing mercury can be used to measure the temperature

of an oven at 150°C because mercury is a ....................................... at 150°C.

1 mark

maximum 7 marks

2. Spots may be caused by bacteria in the skin. A researcher investigated the effect of spot-lotion on bacteria.

(a) He grew bacteria on the surface of jelly in a Petri dish.

At what temperature would the bacteria reproduce quickly?

Tick the correct box.

100°C 4°C

37°C –15°C1 mark

(b) The researcher placed two small paper discs onto the surface of the jelly.One disc had been soaked in spot-lotion. The other disc had been soaked in water. The diagrams below show the jelly at the beginning of the experiment and two days later.

paper d isc soakedin spo t-lo tion

c lea r area

surface coveredw ith bacteria

paper d iscsoaked in w a te r

tw o days la terat the beg inn ing of the experim ent

Suggest what had happened to the bacteria in the clear area around the paper disc soaked in spot-lotion.

……………………………………………………………………………………….

……………………………………………………………………………………….1 mark

(c) What was the control in this experiment?

……………………………………………………………………………………….

……………………………………………………………………………………….1 mark

(d) Give two safety precautions the researcher should take to avoid contact with the bacteria.

1. ……………………………………………………………………………………

2. …………………………………………………………………………………….2 marks

Maximum 5 marks

3. One evening Jenny and Leah ate chicken sandwiches which had been in their school bags all day. There were harmful bacteria in the food. The next day both girls became very ill. Their doctor gave them antibiotics to take for eight days.

The graph represents how antibiotics affect the number of bacteria in the body.

00 1 2 3 4 5 6 7 8 9 10

tim e, in dayssandw icheaten

an tib io ticsstarted

num ber ofharm fu lbacte ria inthe body

(a) Use the graph to explain why the girls did not become ill until the day after eating the sandwiches.

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

.....................................................................................................................1 mark

(b) After taking the antibiotics for eight days Jenny was completely better. Explain why she got better.

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

.....................................................................................................................1 mark

(c) Leah should have taken the antibiotics for eight days. She felt much better after five days and stopped taking the antibiotics. Two days later she felt very ill again.Use the graph to help you explain why Leah became ill again.

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

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

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

.....................................................................................................................2 marks

(d) Food will keep longer if it is placed in a refrigerator at 2°C.Refrigeration does not kill bacteria.What effect does the low temperature have on bacteria?

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

.....................................................................................................................1 mark

Maximum 5 marks

Energy

1 The drawings below show what happens to the energy supplied to four appliances.

kettle

98% o f the energy isused to heat the w a ter

2% o f the energy is w asted

light bu lb

% o f the energyis g iven ou t as ligh t

95% o f the energy is w asted

radio

50% o f the energyis g iven ou t as sound

50% o f the energy is w asted

m ixe r

% of the energy is w asted

40% o f the energy isused to m ove the w h isks

(a) (i) What percentage of energy of the light bulb is given out as light?Write your answer on the line by the light bulb.

1 mark

(ii) What percentage of energy is wasted by the mixer?Write your answer in the box by the mixer.

1 mark

(iii) Complete the sentence below.

Parts of the mixer become hot because some of the electrical

energy is changed into .......................................... energy which is

wasted.

1 mark(b) Energy is wasted as sound in many appliances.

Which appliance in the drawings produces sound which is not wasted?

........................................................1 mark

(c) In which of the appliances is the highest percentage of energy wasted?

........................................................1 mark

Maximum 5 marks

2. The drawing shows Mark’s house. He uses three methods to generate electricity.

(a) Draw a straight line from each of the two methods below to the main energy resource used to generate electricity. Draw only two lines.

m ethod energy resource

air m ovem ent

chem icals

sola r ce lls

sun light

heat

pe tro l generato r

2 marks

(b) (i) The solar cells cannot work at night.Give the reason for this.

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

.............................................................................................................1 mark

(ii) The wind turbine cannot generate electricity all the time.Give the reason for this.

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

.............................................................................................................1 mark

Maximum 4 marks

3. Coal is a non-renewable energy resource.

(a) Give two other non-renewable energy resources.

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

2. ..................................................................................................................2 marks

Wood is a renewable energy resource.

(b) Why can wood be described as a renewable energy resource?

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

......................................................................................................................1 mark

(c) Give two other renewable energy resources.

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

2. ..................................................................................................................2 marks

(d) Complete the statement below to describe what happens when wood burns.

When wood burns, chemical energy in the wood is transformed

into .............................. energy, which is transferred to the surroundings.1 mark

Maximum 6 marks