Answers to revision end of unit tests
Chapter 1
Answers to End-of-unit test
1 The fat is stored 2 Up to 24 hours 3 Mouth 4 Gullet (oesophagus) 5 Stomach
6 Small intestine (ileum) 7 Large intestine (colon) 8 Rectum 9 It only provides some of the food types and is
unbalanced, having more fat than we need. 10 Glucose
11 Liver and butter
112 Roughage 13 Fatty acid and glycerol 14 Sugars 15 Because the starch molecule is so large it partially
stops light getting through (refraction). 16 Their weight falls outside the range that normal
healthy people display.
17 For respiration/to provide a source of energy. 18 Proteins 19 The glycerol from the breakdown of fats. 20 b, c, f, d, h, a, i, e, g
Chapter 2
Answers to End-of-unit test
1 Even though the liquid is still, the particles wander randomly.
2 Shiny 3 It has a fixed shape. 4 It takes the shape of the container it is in but has a
fixed volume. 5 Melting point 6 An element 7 About 106 (allow between 103 and 112) 8 Carbon – non-metal, magnesium – metal, sulphur –
non-metal, calcium – metal 9 It is a metal.
10 No, it is an insulator. 11 Suitable sketch showing non-metals on right-hand
side of the Periodic Table. 12 Does it contain only one type of atom? 13 Try to split it into simpler substances. 14 A molecule / a compound 15 Sodium chloride 16 Simple molecule showing two hydrogen atoms
joined to one oxygen atom. 17 Simple molecule showing two oxygen atoms joined
together. 18 Carbon oxygen → carbon dioxide 19 He helium, F fluorine, Na sodium 20 Simple molecular diagram showing one carbon atom
reacting with two oxygen atoms to form a carbon dioxide molecule.
Chapter 3
1 From the Sun 2 It rises 3 Arrow showing energy transfer to letter (from
letterbox) 4 a) 80 °C
b) i) rises ii) falls
c) 0 5 Arrow showing energy transfer to Earth (from Sun) 6 It’s further from the Sun 7 Energy transfer in and energy transfer out are the same 8 Changes to atmosphere 9 Arrow showing energy transfer from person to
surroundings 10 Wear warm clothes for insulation 11 Eat food (respiration) 12 A material that allows little conduction 13 It traps air (between fibres) 14 Sweats (and increases blood flow to skin) 15 a) radiation
b) convection
c) conduction 16 Sketch
17 Loft insulation (fibre glass); double glazing 18 Cold weather 19 Advantage – renewable resource, low transport
costs, etc. Disadvantage – needs sunlight, expensive to install
Chapter 4
1 b) Glucose 2 c) The cells 3 The circulatory system (accept blood system or
blood for level 4)
4 To carry oxygen around the body 5 False 6 False 7 True 8 True 9 False 10 True
Chapter 5
1 No, salt water is a solution, so it is a mixture of pure salt and pure water.
2 Oxygen 3 Air, Earth, Fire, Water 4 Nitrogen 5 They go into the air. 6 This gets added to the air. 7 Any reaction where heating causes a substance to
fall apart into two other substances e.g. sugar being
heated. 8 Any reaction where a metal displaces another metal
from a solution e.g. copper sulphate and iron. 9 Any reaction where a natural material helps break
down another substance and itself remains
unchanged in the reaction e.g. yeast and sugar. 10 Simple drawing showing one atom of aluminium
combining with three atoms of chlorine. 11 Argon does not need to share its electrons with any
other atom to be stable. 12 Simple drawing of a molecule made of two identical
atoms combined. 13 Because when metals burn they gain in weight.
Phlogiston could not have negative mass. 14 That it is a chemical change that transfers energy as
heat. 15 1 mark for plotting points; 1 mark for line of best fit. 16 & 17 1 mark for plotting points; 1 mark for line of
best fit. 18 0.50 g 19 1.67 g
20 The ratio of the masses of copper and oxygen stays constant.
Chapter 6
1 Both can act at a distance. Both can exert forces of attraction.
2 Magnetic force may be attractive or repulsive, but gravitational force is always attractive.
3 a) Repel b) Attract
4 Small magnet that spins to line up with the Earth’s magnetic field.
5 Pattern; arrows 6 Arrows; show force on a small north pole 7 Field is stronger where lines are closer together. 8 E.g. iron 9 Stroke it with a magnet.
10 Use many coils of wire; use a big electric current; use an iron core.
11 a) It varies b) i) Current vibrates (goes backwards and
forwards) so magnetic field also vibrates. ii) Changing current produces changing force
that makes the loudspeaker cone vibrate. 12 Pattern (concentric circles)
13 a) i) To make the magnetic field (magnetism) as strong as possible.
b) ii) To help to switch the current in the circuit on and off.
14 Current in coil; makes it magnetic; so it attracts the hammer; the springy metal strip moves away from the adjustable screw; the circuit is broken; the coil loses its magnetism and the hammer moves back; that reconnects the circuit and the process starts again.
15 Varying current in the coil; makes the magnetic force vary; the coil and core move to match the current.
16 Motors, relays, meters (some) etc.
Chapter 7
1 a) b) c)
To measure their temperature To listen to their heart To check their blood pressure
2 Micro-organism 3 It does not feed and does not excrete 4 Brewing beer and making bread 5 The mould killed the bacteria 6 Darkness, warmth and moisture (any two) 7 Water-borne, airborne, food-borne (any two) 8 The body is trying to kill the invading micro-
organisms by raising the temperature 9 Streptococcus, Salmonella, Campylobacter, E. coli,
measles virus, chickenpox virus (any two) 10 White blood cells 11 Injection or tablets
12 A drug that can fight bacterial infection 13 Alexander Fleming 14 Dry your toes after swimming/bathing, wash your
feet daily, wear sandals in warm weather, wear cotton socks, avoid tight footwear, go barefoot at home, use anti-fungal foot powder (any three)
15 Micro-organisms
16 Microscope
17 Helpful
18 Yeast
19 Vaccination
20 Smallpox
Chapter 8
1 True – rocks are usually a mixture of mineral grains. 2 Their roots grow in cracks and push the rock apart. 3 Granite – small, light-coloured crystals at random
(other answers possible). 4 Sandstone – light-coloured round particles in layers
(other answers possible). 5 See table on page 92 for answers. 6 They are broken up and become rounded. 7 It expands (by about 10%). 8 Heating causes expansion which makes flakes of
rock detach from the surface. 9 They are cemented together by once-dissolved
minerals. 10 The moving water carries suspended mud particles
into the house. When the water stops moving, the
mud particles settle out. 11 Lots of loose rock fragments at the bottom of a cliff
caused by weathering. 12 It contains dissolved carbon dioxide which is an
acidic gas. 13 Pollution gases such as sulphur dioxide and nitrogen
oxides dissolve in the water. 14 See Figure 1 on page 94 of Pupil’s Book B. 15 Erosion. 16 They are deposited when rock particles settle out of
water. 17 Acidic rainwater dissolves away limestone deep
underground. 18 The slowing down of the water. 19 Calcium carbonate (marble) acidic rain → calcium
salt carbon dioxide. 20 Some of the mineral grains in granite get dissolved
by the acidic rainwater.
Chapter 9
Went over in class