Answer to Workbooks
New Biology — a modern approach
Class Practice
1.1 What is biology?
1. Zoology
2. Cytology
3. Human biology
4. Botany
5. Genetics
6. Ecology
7. Microbiology
8. Taxonomy
1.5 How do we study biology?
A. 1. Making observations
2. Making hypothesis
3. Doing experiments
4. Collecting new data
5. Revision
B. 1. Do not put the labels on the diagram itself.
2. Labels should be written horizontally.
3. The labelling lines should not intersect one another.
4. Give the diagram a suitable title, and include the scale of magnification.
1.6 The characteristics of living organisms
A. 1. nutrition
2. respiration
3. excretion
4. growth
5. reproduction
6. sensitivity
7. movement
B. The motor car does not have the characteristics of growth, reproduction and sensitivity.
C.
And only combusting (but not respiration) occurs in the motor car to release energy.
1. T
2. F
3. F
4. F
5. F
2. Green plants also need food. They can make their own food by photosynthesis.
3. Respiration occurs in every living cell.
4. Growth is the increase in size, body weight and complexity of an organism.
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5.
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Plant movements are comparatively slow growth movements involving only parts of
their bodies.
2.2 The functional roles of the organic substances in organisms
A. 1. (a) carbon
(b) hydrogen
(c) oxygen
2. (d) glucose
3. (e) starch
(f) glycogen
4. (g) Cellulose
5.
6.
3.
(h) energy
(i) amino acids
1. F
2. T
3. F
4. F
5. F
In a carbohydrate molecule, the hydrogen atoms and the oxygen atoms are in the
ratio of 2:1.
Proteins contain energy. It can be used as fuel when carbohydrate or fat is in shortage.
4.
5.
DNA is found in the cells of all organisms.
DNA is present in the nucleus
B.
1.
2.3 The importance of water to life
1. T
2. F
3. T
4. T
2. 90% of the human plasma is water.
3.2 Microscope
A. A objective
B clip
C stage
D condenser
E mirror
F eyepiece
G course adjustment
H fine adjustment
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B.
I
1.
revolving nosepiece
G
2.
3.
4.
5.
6.
7.
8.
9.
D
E
C
B
A
I
F
H
New Biology — a modern approach
3.3 Basic structure of a cell
A. 1. a
2. c
3. c
4. b
5. a
6. c
7. a
8. c
9. a
B.
1.
2.
3.
4.
5.
6.
7.
8.
cell membrane
cytoplasm
mitochondria
chloroplasts
cell wall
nucleus
vacuole
chromosomes
3.5 The cell as a basic unit of life
1.
2.
nucleus  cell  tissue  organ  system  organism
(i) E
(ii) C, D
(iii) D
(iv) A
(v) B
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4.1 Metabolism
1. b
2.
3.
4.
5.
a
b
b
c
4.3 The nature and properties of enzymes
1. T
2. F
3. F
2.
3.
7.
4. T
5. T
6. T
7. F
8. T
Some enzymes may leave the cell and exert their actions outside the cell. (Other enzymes
exert their action inside the cell.)
Catalase is one of the enzymes that can be found in plant and animal tissues.
Not all enzymes are denatured at high pH. Different enzymes may have different
optimum pHs.
4.4 The mechanism of enzyme action
(a) enzyme-substrate complex, product, enzyme
(b) Anabolism
(c) Lock-and-key hypothesis
(d) Both the active site of the enzyme and the key have a specific shape which fits into a
particular substrate and lock respectively.
4.5 Factors affecting enzyme activity
(a) 45(±2)ºC
(b) Enzyme is inactive at low temperatures.
(c) kinetic, enzyme, substrate, faster, collide
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Answer to Workbooks
(d)
Enzyme activity
Temperature (ºC)
60
50
40
30
20
10
0
4.6 Movement of substances across the cell membrane
1. (i) b
(ii) a
(iii) b, c
(iv) b
2.
3.
(v)
(a)
(b)
(c)
(d)
(e)
(f)
a
√
osmosis
lower
√
not
rise
(g) √
(i) (a)
(b)
(ii) (c)
(iii) (d)
(iv) (e)
(f)
(v) (g)
(h)
(i)
(j)
higher
lower
mineral salts
carbon dioxide
Oxygen
carbon dioxide
water
higher
lower
selectively permeable
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New Biology — a modern approach
5.2 Classification
1. (a) taxonomy
2.
(b)
(c)
(d)
(e)
species
common features
interbreed
offsprings
5.6 Kingdom plantae
A. 1. (a) prokaryotes
(b) nucleus
2. (c) saprophytic
6.
7.
1.
(d) parasitic
(e) algae
(f) water
(g) hyphae
(h) spores
(i) mosses
(j) ferns
(k) rhizoids
(l) Gymnosperms
fungi
2.
3.
4.
5.
6.
7.
ferns
algae
prokaryotes
mosses
gymnosperms
flowering plants (angiosperms)
3.
4.
5.
B.
C.
(a) mosses
(b) ferns
(c) gymnosperms
(d) flowering plants (angiosperms)
(e) dicotyledons
(f) monocotyledons
5.7 Kingdom animalia
1. birds, mammals
2. amphibians (adult), reptiles, birds, mammals
3. amphibians (tadpoles), fish
4. fish, reptile, birds (on the legs)
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5.
6.
birds
reptiles, birds
7.
8.
9.
10.
mammals
birds
mammals
amphibians
New Biology — a modern approach
5.8 Identifying organisms with simple keys
(i) A snail
B earthworm
C ant
D spider
E centipede
(ii) Ant, spider and centipede belong to the same group. They have segmented body and
jointed legs. Their bodies are covered with exoskeleton.
5.9 Viruses
1.
2.
3.
4.
1.
2.
F
F
F
T
Virus and bacterium are two different kinds of things.
A virus has no cell wall or cell membrane. It only consists of a protein coat.
3. Virus does not have chromosomes. There is only a coiled string of nucleic acid
inside a virus.
6.1 What is an ecosystem?
1. population
2. habitat
3. microhabitat
4. environment
5.
6.
7.
community
ecosystem
ecology
6.2 What is environment?
1. T
2. T
3. F
4. T
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2.
5. F
Some poikilotherms hibernate in winter. Some small mammals also hibernate in winter.
5.
Some animals are active during the daytime; while some are active at night.
6.3 Energy flow within an ecosystem
1. T
2. F
3. F
4. T
5. F
6. T
2.
3.
5.
7. T
The primary consumers are not necessarily larger in size than the secondary consumers.
Owl and fox are the rarest organisms in the ecosystem.
The total biomass of grass and wheat exceeds that of all the consumers in the food web.
6.4 The accumulation of toxic substances along food chains
(a) parts per million
(b) DDT drained off by water into river (by leaching) is absorbed actively by water plants. A
small fish eats a large amount of water plants, and then a large fish eats a lot of small fish,
and finally a bird eats a lot of large fish. Since DDT cannot be excreted or broken down, it
is accumulated along the food chain.
6.5 Cycling of materials
1. (a) A - respiration
B - photosynthesis
C - feeding
D - combustion/burning
(b) X is decay/respiration. Decomposers are involved in this process.
2. (a) Animals take in plant material, breaking down plant protein into amino acids.
Animals synthesise their protein from the absorbed amino acids.
(b) nitrogen fixing bacteria
They are found in the root nodules of leguminous plants.
(c) by decomposition / putrefaction
decomposers / putrefying bacteria
(d) Process C is nitrification.
Nitrifying bacteria are involved.
(e) denitrifying bacteria
6.6 Ecological interdependence of organisms
1. (a) commensalism
2. (b) mutualism
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3.
4.
5.
New Biology — a modern approach
(c) predation
(d) predator
(e) prey
(f) parasitism
(g) competition
7.2 Human activities and pollution
A.
1. F
2. F
3. F
4. T
1.
2.
3.
6.
B.
7.
1.
2.
3.
4.
5.
6.
7.
5. T
6. F
7. F
8. T
9. T
10. T
Rain is naturally acidic, with a pH value around 5-6.
The main cause of acid rain is the release of sulphur dioxide and nitrogen dioxide
from the combustion of fossil fuels.
Carbon dioxide is one of the greenhouse gases that cause global warming.
Algal bloom leads to the deoxygenation of water. Fish and other organisms may die
of suffocation.
Detergents contain added phosphates which encourage algal growth.
B
F
C
A
G
D
E
7.3 The Earth's resources
1. Renewable resources can be regenerated after consumption, e.g. timber and fish in the
ocean.
2. non-renewable resources cannot be regenerated after use, e.g. oil and coal.
7.4 The undesirable effects of over-exploitation of resources
A.
• increase the carbon dioxide concentration in the atmosphere
• soil erosion may occur
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• destruction of natural habitats
• loss of species / cannot maintain a diversity of species
B.
C.
1. T
2. T
3. F
4. F
5. T
3. The three major forms of fossil fuels are coal, petroleum and natural gas.
4. The energy we use nowadays mainly comes from fossil fuels.
Over-consumption of fossil fuels leads to the release of carbon dioxide, sulphur dioxide
and nitrogen dioxide. Carbon dioxide will cause global warming while sulphur dioxide
and nitrogen dioxide will form acid rain.
7.5 Environmental protection
1. F
2. T
3. F
4. T
5. F
1. Sustainable development is the development that meets the needs of the present without
doing damage to the prospects of future generations.
3.
5.
Biodiversity can be used to indicate the ‘biological health’ of a particular habitat.
With a good supply of oxygen, micro-organisms in the sewage break down organic matter
into inorganic compounds.
8.2 The requirements for photosynthesis
1. (a) carbon dioxide
(b) water
(c) solar energy/sunlight
(d) carbohydrates/glucose
(e) Oxygen
2.
3.
(f) mesophyll
(g) stomata
8.3 Investigations to study the requirement for photosynthesis
A. Multiple Choice Questions
1. D
2. C
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B.
New Biology — a modern approach
Structured Questions
1.
2.
(a) 1  4  3  2
(b) to soften the leaf
to extract chlorophyll/decolourise the leaf
(a) to destarch the plant
(b) (i) to show that carbon dioxide is necessary for photosynthesis
(ii) to absorb carbon dioxide
(c) (i) to show that light is necessary for photosynthesis
(ii) to exclude light / make sure the plant cannot absorb light
(d) Leaf A - blue black, leaves B and C - brown
8.4 The photosynthetic process
1. F
2. T
3. F
4. F
1.
3.
4.
The chlorophyll mainly absorbs red and blue light of the spectrum for photosynthesis.
Most of the green light is reflected.
During the light reactions, water is split into hydrogen and oxygen. Oxygen is released
immediately and hydrogen combines with carbon dioxide to form carbohydrate in the
dark reactions.
Dark reactions immediately occur after the light reactions. They both take place in the
daytime.
8.5 The effects of environmental factors on the rate of photosynthesis
(a) When the distance between the beaker and the table lamp increases, the light intensity
decreases. Therefore, the rate of photosynthesis decreases with the increase in distance.
(b) This solution provides carbon dioxide.
(c) A large beaker can hold a greater volume of dilute sodium hydrogencarbonate solution.
This provides more carbon dioxide and absorbs more heat energy released by the table
lamp.
(d) Crops grow faster in a greenhouse because it is warmer inside. The carbon dioxide
concentration can also be increased in a greenhouse to increase the photosynthetic rate of
the crops.
8.6 The products of photosynthesis
A. 1. A
2. A
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B.
1.
2.
1.
3.
4.
New Biology — a modern approach
F
T
3. F
4. F
5. T
6. T
Some of the oxygen produced during photosynthesis is used for respiration. The rest
of it diffuses out into the atmosphere.
Sucrose can be carried to actively growing regions where it is changed to glucose.
Plants make use of glucose to make many organic substances in addition to starch
and sucrose.
8.7 Leaves-organs of photosynthesis
A. 1. B
2. A
B. (a) i. veins
ii. cuticle
iii. epidermis
iv. palisade mesophyll
v. spongy mesophyll
vi. xylem
vii.
viii.
(b) 1.
2.
3.
4.
5.
6.
7.
9.1
phloem
stoma
Gases can diffuse into and out of the leaf easily.
Diffusion is faster and more sunlight can be absorbed.
to carry water and minerals from the soil to the leaf
to carry the product of photosynthesis away from leaf
for gaseous exchange, to allow carbon dioxide in the atmosphere to diffuse into
the leaf
to prevent excess water loss
for diffusion of gases
What is respiration?
1. F
2. T
3. T
4. F
5. F
6. T
7. F
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Answer to Workbooks
1.
4.
5.
7.
9.3
New Biology — a modern approach
8. T
All living cells require energy.
The process of burning is different from that of respiration.
Burning cannot occur inside a cell even if a sufficient amount of oxygen is present.
The reactions of respiration are controlled by enzymes while burning does not involve
enzymes.
The chemistry of respiration
1. F
2. T
3. T
1.
4.
6.
8.
4. F
5. T
6. F
7. T
8. F
9. T
Respiration in plants occurs all the time.
ATP stores energy for a short period only.
ATP is made inside the mitochondria.
ATP cannot be transported from cell to cell. It has to be used inside the cell in which it is
made.
9.4
Aerobic and anaerobic respiration
A. 1. (a) glucose
(b) carbon dioxide
(c) aerobic
2. (d) glucose
(e) ethanol
(f) alcoholic fermentation
3. (g) lactic acid
B.
2.
3.
4.
(h) lactic acid fermentation
1. T
2. F
3. F
4. F
5. T
Mitochondria are involved in aerobic respiration only.
Skeletal muscles carry out aerobic respiration if sufficient oxygen is available.
Mitochondria are present in muscle cells.
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10.1 Nutrition
1. T
2.
4.
2. F
3. T
4. F
Green plants synthesise organic substances by using simple inorganic substances from
their surroundings. Energy is needed in this process.
Animals, fungi and most bacteria are heterotrophs.
10.2 The importance of minerals for proper growth in green plants
1. (a) active transport
2.
3.
4.
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
major elements
trace elements
proteins
nitrates
small leaves
weak stems
chlorophyll
poor growth
yellowing of leaves
10.3 Fertilizers
1. T
2. T
3. F
4. F
5. T
3. The proportion of nitrogen, phosphorus and potassium in chemical fertilizers is not
always the same.
4. Natural fertilizers have to undergo decay and release mineral salts slowly. They cannot
be used immediately.
10.4 Gaseous exchange in plants
A. 1. (a) stomata
(b) diffusion
2. (c) spongy
(d) air space
3. (e) cork cells
(f) lenticels
B.
1. F
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2.
3.
1.
3.
4.
T
F
4. F
Green plants carry out respiration all the time.
The rate of respiration in plant cells is more or less constant throughout the day.
At compensation point, the rates of photosynthesis and respiration are equal.
10.5 Transpiration
A. 1. D
2. D
3. A
4.
B.
1.
4.
C
1. F
2. T
3. T
4. F
5. T
During transpiration, transpiration stream carries water and dissolved mineral salts
from the roots to the leaves.
The higher the temperature, the greater is the rate of transpiration because water
evaporates faster.
10.6 Absorption of water and mineral salts by the root
1. C
2. F
3. E
4. G
5. H
6. D
7. A
8. B
10.7 Transport in flowering plants
1. F
2. F
3. T
4. T
5. F
1. Xylem is made of vessels and each vessel is made up of many dead cells which are
joined end to end.
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2.
5.
New Biology — a modern approach
Xylem vessels run from roots, up through the stem, and finally branch out into every leaf.
Sieve tubes are living cells with cytoplasm.
10.8 Support in plants
(a) turgidity — A and D
rigidity — B and C
(b) Most of the cells become flaccid because the rate of transpiration is faster than that of
water absorption. The plant will wilt.
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New Biology — a modern approach
11.2 Food and food substances
1. F
1.
3.
5.
2. T
3. F
4. T
5. F
Most heterotrophs are animals. (Some saprophytic fungi are also heterotrophs.)
The food we eat every day make up our diet.
As vitamins, minerals and dietary fibres are necessary for keeping us healthy, they are
called protective food substances.
11.3 Carbohydrates
A.
1. T
2. T
3. F
4. F
5. T
6. F
7. T
3. In disaccharides only sucrose is non-reducing sugar.
4. Both hydrolysis and condensation require the presence of suitable enzymes.
B.
6.
1.
2.
3.
4.
5.
6.
Polysaccharides do not give a sweet taste.
F
C
D
E
B
A
11.5 Proteins
1. T
2.
4.
6.
2. F
3. T
4. F
5. T
6. F
A molecule of fat is made up of three molecules of fatty acid combined with one
molecule of glycerol.
Essential amino acids cannot be made in human body.
The excess amino acids are broken down in the liver by deamination.
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11.6 Vitamins
1. T
2. F
3. F
4. T
5. F
6. T
7. F
2. Plants can make their own vitamins from simple substances.
3. Fat-soluble vitamins are more heat resistant than water-soluble vitamins.
5.
7.
Lack of vitamin A causes night blindness.
Vitamin D helps the absorption of calcium and phosphorus in the small intestine.
11.9 Water
1. C
2. A
3. C
4. B
5. D
11.10 Food tests
(a) Clinistix paper
(b) colour changes from pink to blue
(c) Benedict's test
(d) formation of brick-red ppt.
(e) iodine test
(f) colour changes from brown to blue black
(g) Albustix paper
(h) colour changes from yellow to green
(i) spot test
(j) formation of permanent translucent spot
(k) DCPIP test
(l) The blue DCPIP is decolourised
11.12 Food and energy
A. Q
S
R
P
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Answer to Workbooks
B.
1.
2.
P
Q
C.
1. F
2. F
3. F
4. T
5. T
1. A balanced diet contains the right amount of all the food substances.
2. A pregnant woman needs extra food because she needs more energy for the growth
of the foetus.
3. Energy for living comes from carbohydrates, fats and proteins.
11.13 The health problems resulting from an improper diet
1. C
2. D
3. B
4. A
12.1 The processes of nutrition in humans
1. C
2. D
3.
4.
5.
E
B
A
12.2 The human digestive system
(a) oesophagus
(b) stomach
(c) duodenum
(d) ileum
(e) appendix
(f) colon
(g) rectum
12.3 The teeth
A. Functions in humans
biting and cutting
tearing
crushing and grinding
crushing and grinding
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8
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19
Answer to Workbooks
B.
1.
2.
dental formula
enamel
3.
4.
5.
6.
7.
8.
dentine
crown
root
periodontal membrane
pulp cavity
neck
New Biology — a modern approach
12.5 Periodontal disease
1. T
4.
2. F
3. T
4. F
5. F
6. T
7. F
8. T
Bacteria in the plaque break down sugar and starch in the food into acid which dissolves
the enamel, causing tooth decay.
If tooth decay is not serious, the tooth can be repaired by a dentist.
5.
7.
The rate of tooth decay can be reduced by adding fluoride to drinking water.
Calculus can be scraped off by a dentist.
2.
12.6 The functions of different parts of the alimentary canal and its associated glands
A. 1. duodenum
2. ileum
3. mouth cavity
4. salivary glands
5. stomach
6. pancreas
B.
7.
8.
9.
10.
11.
12.
(a)
(b)
(c)
rectum
anus
colon
liver
gall bladder
oesophagus
mouth cavity
surface area
digestive enzymes
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(d) salivary glands
(e) pancreas
(f)
(g)
(h)
(i)
(j)
(k)
C.
stomach
pancreas
bile
liver
gall bladder
peristalsis
1.
2.
T
F
5.
3. F
4. T
5. F
6. T
7. T
8. F
Food inside the stomach is churned up to form chyme.
Bile does not contain any digestive enzymes. It contains bile salts which emulsify
fats into oil droplets.
Water-soluble vitamins and minerals are absorbed at the ileum.
8.
Most water in the gut is absorbed in the small intestine. Only some of it is
2.
3.
12.7 Assimilation
1. B
2. C
3. A
4. A
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New Biology — a modern approach
13.1 Gaseous exchange
1. F
1.
5.
6.
2. T
3. T
4. T
5. F
6. F
Gaseous exchange is the exchange of oxygen and carbon dioxide between an organism
and its surroundings.
Gaseous exchange also occurs in plants.
Gaseous exchange also involves other gases such as water vapour.
13.2 The general plan of the human breathing system
A.
1. F
2. T
3. F
4. F
5. T
1. The blood capillaries in the nasal cavity can warm the incoming air before it goes
into the lungs.
3. Breathing stops during swallowing because the opening of the trachea is closed by
B.
4.
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
the epiglottis.
When the vocal cords vibrate, sound is produced.
vocal cord
alveoli
trachea
bronchi
larynx
epiglottis
pleural membrane
diaphragm
(i)
(j)
intercostal muscles
rib cage/thoracic basket
13.3 The process of gaseous exchange in the alveoli
1. The oxygen dissolves in the moisture of the alveoli. It diffuses across the walls of the
alveoli and the capillaries into the blood. It then diffuses through the cell membrane into
the red blood cell.
2. 1. The walls of the alveoli are very thin which provide a short distance for diffusion of
gases.
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Answer to Workbooks
2.
3.
3.
There are numerous alveoli which provide a large surface area for diffusion of gases.
The alveoli are surrounded by a network of capillaries. They provide a rich blood
supply to transport gases to and from the respiratory surface.
4. The walls of the alveoli are moist. Thus the oxygen can dissolve in this fluid and
diffuse across the walls of the alveoli.
(Any three)
The blood in A contains more carbon dioxide and less oxygen than that in B.
13.4 The mechanism of ventilation
1. A, C
2.
Location
Intercostal
muscles
Diaphragm
muscles
State
Function
Resulting
Resulting
thoracic
volume
thoracic
pressure
Move ribs and
Contracated
Contracted
sternum upwards
and outwards
Flatten the
diaphragm
Air
movement
Air flows
Increased
Decreased
From the
atmosphere
into the
lungs
The relation of exercise to energy requirement, rate of cellular respiration and ventilation
1.
Student B
2.
No.
3.
He will have similar breathing depth when doing exercise.
4.
(a) increases
(b) decreases
(c) nerve impulses
(d) respiratory centre
(e) faster
(f) intercostal
(g) diaphragm
(h) deeper
(i) faster
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Answer to Workbooks
14.2 Blood Vessels
A.
1. F
1.
2.
3.
B.
C.
1.
2.
3.
4.
5.
(a)
2. F
3. F
4. T
5. T
Small organisms have a large surface area to volume ratio. They do not need a
circulatory system.
The walls of arteries contain thick layers of muscles and elastic fibres. The walls of
veins also contain muscles and elastic fibres but they are much thinner.
The walls of the capillaries are very thin. They are only one-cell-thick.
B
D
A
C
E
1.
2.
X:
Y:
Z:
muscles and elastic fibres
lining of wall
artery
vein
capillary
(b) to withstand the high pressure of blood
(c) Valves can be found in Y but not in X.
14.3 The heart
1. (a) A. superior vena cava
B. coronary artery
C. aorta
D. pulmonary artery
(b) It carries blood to the heart muscles to supply oxygen and nutrients.
(c) C carries oxygenated blood while D carries deoxygenated blood.
(d) left atrium
left ventricle
2.
right atrium
right ventricle
(e) (i) bicuspid valve
(ii) tricuspid valve
(iii) heart tendon
It prevents the valves from being turned inside out.
(a)
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Answer to Workbooks
(b) P: aorta
Q: ventricle
R: atrium
14.4 Blood circulation in man
1. F
2. T
1.
3.
4.
3. F
4. F
In man, the blood flows through the heart twice in one complete circulation. This is
called double circulation.
Deoxygenated blood from the body tissues returns to the right atrium.
After gaseous exchange, the oxygenated blood flows through the pulmonary vein back to
the left atrium.
14.5 What is blood?
1. A, B, C, D
2.
3.
4.
5.
6.
7.
8.
9.
10.
C, D
B
B
D
E
A
A
C
C
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11. C
14.6 The functions of mammalian blood
14.7 What is the lymphatic system?
1. C
2. C
3. A
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15.1 Irritability
1. C
2.
3.
4.
5.
6.
7.
D
A
B
E
G
F
15.2 The five senses
1. T
2.
3.
5.
2. F
3. F
4. T
5. F
6. T
Skin receptors are distributed unevenly all over the body.
The fingertips are sensitive to touch, pressure, change in temperature and pain.
The sense of smell is more sensitive than the sense of taste.
15.3 The eye
(a) A is eyebrow and B is eyelash.
Eyebrow prevents the sweat on the forehead from going into the eyes.
Eyelash helps to stop dirt from entering the eyes.
(b) Tears moisten eyeball surface.
Tears wash eyeball surface during blinking.
The fluid contains lysozome which kills bacteria. (any two)
(c) Structure E shows that this is a left eye.
15.4 Structure and functions of the eye
1. cornea
2.
3.
4.
5.
6.
7.
8.
9.
10.
sclera
retina
lens
optic nerve
choroid
yellow spot
blind spot
iris
suspensory ligaments
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11. pupil
15.5 The control of the amount of light entering the eye
(a) smaller
(b) circular
(c) radial
(d) less
15.6 The accommodation of the eye
A. 1. (a) accommodation
2. (b) ciliary muscles
B.
(c) suspensory ligaments
(d) thicker
(e) retina
(a) Diagram I - long sight
Diagram II - short sight
(b)
Diagram I
Diagram II
16.1 What is coordination?
(iii)  (iv)  (vi)  (v)  (i)  (ii)
16.2 The general plan for the nervous system
Consists of
(b) brain
(a) Central nervous system
(c) spinal cord
Nervous
system
(d) cranial nerves
Peripheral nervous system
(e) spinal nerves
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16.3 Neurones
(a) Motor neurone
(b) A – cytoplasm
B – nucleus
C – axon/nerve fibre D – myelin sheath
(c) D is made of fat. It prevents the spread of nerve impulses and helps to speed up the rate
of transmission of nerve impulses.
(d) X is an effector, e.g. muscle/gland.
(e) A nerve is made of bundles of nerve fibres grouped together and wrapped by a sheath of
connective tissue.
16.4 Protection of central nervous system
1. (a) cranium/skull
(b) vertebral column
2. (c) cerebrospinal fluid
(d) nourishing the neurones
(e) protecting the brain from mechanical injury
16.5 The functions of the main parts of the brain
1. F
2. T
1.
3.
4.
7.
3. F
4. F
5. T
6. T
7. F
The cerebrum is smaller than the cerebrum. Their structures are not the same either.
The motor areas send out impulses to the effectors.
Grey matter consists of the cell bodies of neurones.
Damage of the medulla may lead to death.
16.7 Reflex action
(a)
The stimulus should be applied on the tendon below the knee cap.
(b) The leg would give a little kick.
(c) Stretch receptor  neurone X  neurone Y  thigh muscle.
(d) Yes, because the nerve impulses are also carried to the brain through another neural
pathway.
(e) Because the cell body of the motor neurone is located in the spinal cord.
(f ) The brain could feel the tap but the leg would not kick immediately.
(g) Cerebrospinal fluid.
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16.8 What are voluntary actions?
Reflex actions
Voluntary actions
(a) Pathway taken by nerve
impulses
not involving cerebrum
involving cerebrum
(b) Is a receptor involved?
yes
may not be involved
not under control of the will
under control of the will
(d) Inborn or not inburn?
inborn
not inborn
(e) Speed of response
faster
slower
always the same
may be different
(c) Control
(f ) Response to the same
stimulus
16.10 Similarities and differences between hormonal and nervous coordination
1. F
2. F
3. F
4. T
5. T
1.
2.
3.
6.
8.
6. F
7. T
8. F
Hormone and enzyme are two different substances.
Exocrine glands but not endocrine glands have ducts to carry their secretions to the exterior.
The Islets of Langerhans are located in the pancreas.
Insulin stimulates the conversion of glucose to glycogen.
The conversion of glycogen to glucose and that of glucose to glycogen take place in the
liver.
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17.2 The human skeleton
1. F
2. T
3. F
4. F
1. The functions of skeleton in vertebrates are for support and movement, for protection,
production of blood cells and storage of minerals (calcium).
3. A bone is made up of living tissues.
4. Cartilage also contains mineral salts.
17.3 General plan and functions of the human skeleton
A.
B.
1.
2.
Axial skeleton
Appendicular skeleton
rib
femur
skull
sternum
pectoral girdle
knee cap
C
A
D
C
B
A
F
E
D
B
A
C
17.4 Joints
1. F
2. T
3. F
4. T
5. F
1. A joint is a place where two or more bones meet.
3. The ligaments hold two bones at a joint so as to prevent dislocation.
5. Hinge joints allow movement in one plane only while ball-and-socket joints allow
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movement in three planes and in all directions.
17.5 Muscles
1. F
2. T
3. F
4. F
5. F
1. There are three main types of muscles in human bodies. Skeletal muscle is one of them.
3. When muscles relax, energy is not required.
4. When a skeletal muscle contracts, it becomes thicker and shorter.
5.
Lactic acid is formed when a muscle remains contracted for a long period.
17.6 Locomotion in humans
A.
1. F
2. F
3. T
4. F
1. Each muscle is attached to the skeleton at both ends by tendons.
2. When a muscle relaxes, it cannot push a bone. Therefore another muscle is
required to pull the bone back to its original position.
B.
4. An extensor straightens a limb when it contracts.
(a) A is biceps (or flexor) and B is triceps (or extensor).
(b) B contracts and A relaxes.
18.2 What are tropisms?
1. F
2. F
3. T
4. T
1. Most plants respond to external stimuli slowly. However some plants can respond to a
2.
stimulus quickly, e.g. Mimosa.
Some plant parts show a positive response towards a unilateral stimulus but some show
a negative response.
18.5 The growth response of roots to water
A. (a)
phototropism
(b)
gravity
(c)
hydrotropism
B.
1. F
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2.
3.
1.
4.
T
T
4.
F
Shoots are positively phototropic while roots are negatively phototropic.
Roots are positively hydrotropic but stems and leaves have no response towards
water.
18.7 More about auxins
1. F
2. T
3. F
4. F
5. T
1.
3.
4.
Auxins are produced at the tips of growing shoots and a small amount is produced by
the root tips.
Auxin at very low concentrations stimulates root growth.
The auxin concentration which causes the highest rate of root growth has no effect on
shoot growth.
18.8 The role of auxins in phototropic and geotropic responses
1. (a) shaded
(b)
faster
(c)
illuminated
(d)
towards
(e)
lower
(f )
gravity
(g) inhibits
(h) upper
(i) lower
(j) downwards
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19.1 Homeostasis
1. F
1.
2.
4.
2. F
3. T
4. F
5. T
Keeping the internal environment of an organism in a steady state is known as
homeostasis.
The internal environment is the tissue fluid that bathes the cells, together with the blood
in blood vessels.
The skin regulates the body temperature by sweating.
19.2 The urinary system
(a) A is the renal artery because it receives blood from Y which has a thick wall and is an
artery. B is the renal vein because it connects to X which has a thin wall and is a vein.
(b) C is ureter. D is urinary bladder. F is urethra.
D stores urine temporarily.
(c) It contracts most of the time. It relaxes during urination.
19.3 The kidney
1. (a) X is nephron. It consists of a Bowman's capsule, a glomerulus and tubules (or
2.
(b)
(c)
(d)
(a)
(b)
(c)
convolutions) (any two).
urea
A is a collecting duct. The fluid inside is urine.
ultrafiltration and reabsorption
glucose, amino acids, urea and salts
The blood in the glomerulus is under high pressure. The substances in (a) are small
enough to pass through the walls of the capillaries and the Bowman's capsule by
ultrafiltration.
Urea is not reabsorbed but most of the water is reabsorbed into the capillaries. As a
result, the concentration of urea increases.
(d) The protein molecules are too large to pass through the walls of the capillaries of
the glomerulus. Thus the concentration of proteins in glomerular filtrate and urine
is zero.
19.4 The functions of the kidney
1. T
2. F
3. F
4. T
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5.
6.
2.
3.
5.
6.
F
F
Kidney is the most important organ for osmoregulation.
If we drink a lot of water, the kidney tubules will reabsorb a smaller proportion of water
from the glomerular filtrate.
Urea, carbon dioxide and bile pigment are metabolic wastes which have to be removed
from the body.
Urea is formed in the liver by the breaking down of excess amino acids by deamination.
It is removed by the kidneys.
19.5 Regulation of body temperature
1. (a) poikilotherms
(b) fish
(c) reptiles
2. (d) homoiotherms
(e) birds
19.6 The structure and functions of the skin
1. E
2. G
3. H
4.
5.
6.
7.
8.
9.
10.
I
D
C
B
F
J
A
19.7 How do mammals control their body temperature?
A.
When it is hot
When it is cold
1. hairs (lie flat/raised)
lie flat
raised
2. erector muscles (relax/contract)
relax
contract
3. arterioles near the skin surface
vasodilation
vasoconstriction
4. sweating
increases
decreases
5. metabolic rate
decreases
increases
does not occur
occurs
6. shivering
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B.
New Biology — a modern approach
1. T
2. F
2.
3.
3. F
4. T
When the body is hot the arterioles near the skin dilate. More warm blood flows to
the superficial blood capillaries.
When the erector muscles contract, hairs become erect for trapping more air. Air
acts as a good insulator of heat.
19.8 Regulation of glucose level in blood
1. F
1.
3.
4.
5.
2. T
3. F
4. F
5. F
If the glucose level in blood is too high, water will leave the cells and enter the blood by
osmosis.
Failure to produce enough insulin results in diabetes mellitus.
Glucose in the urine can be detected by using Clinistix paper.
Diabetics can maintain their blood glucose at a constant level by regular injections of
insulin.
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20.1 What is a disease?
1. F
1.
3.
4.
5.
2. T
3. F
4. F
5. F
Diseases can be classified into non-infectious and infectious diseases. Only infectious
diseases are caused by microorganisms.
The microorganisms that cause diseases are called pathogens which are commonly
known as germs.
Bacteria, viruses, fungi and protoctists can cause diseases.
Some bacteria are useful to humans (e.g. for recycling of materials in nature, treatment
of sewage, production of drugs, etc.) although other bacteria may cause diseases.
20.2 Body defence
Column P
Column Q
Column R
Non-specific defence ●
●
First line of defence
●
●
by white blood cells
●
●
Second line of defence
●
●
by immune system
●
Last line of defence
●
●
by natural barriers
Specific defence
20.3 Non-specific defences
A.
B.
Part of the body
Substance produced
1.
Sebaceous glands
sebum
2.
Eyes
tears
3.
Mouth
saliva
4.
Stomach
5.
Vagina
1.
2.
3.
4.
5.
6.
7.
gastric juice
acid
F
F
T
F
T
T
F
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1.
Though the skin is a physical barrier to prevent infection, pathogens can
nevertheless enter our bodies through the nose, the mouth, or even wounds.
2.
In the trachea, bacteria are trapped by the mucus, and then the mucus is wafted
towards the throat by the beating cilia.
The acid in the gastric juice can kill most of the bacteria in the food.
Phagocytes can only engulf some types of pathogens in the body.
4.
7.
20.4 Specific defences
1. F
2. C
3. G
4.
5.
6.
7.
B
E
D
A
20.5 Immunity and vaccination
1. T
2. F
3. F
4. F
2.
3.
4.
5. T
Vaccine can be administered to both children and adults.
There are different routes of vaccination: injection, scratching the skin and oral administration.
Vaccine is made from dead or weakened pathogens.
21.2 Chromosomes
1. (a) parent cell
(b) daughter cells
2. (c) chromatins
3. (d) homologous
4.
(e) chromatid
(f) centromere
21.3 Mitosis
(2) → (3) → (1) → (4)
21.4 Meiosis
1. F
2. T
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3.
4.
T
F
5.
6.
5. F
6. F
7. T
8. F
Chromosomes replicate once in both mitosis and meiosis.
The number of chromosome in the gametes formed during meiosis is half of that in the
parent cells.
Meiosis takes place in the testes in males and in the ovaries in females.
Both sperms and eggs are haploid.
8.
In flowering plants, meiosis occurs in the anthers and the ovaries.
1.
4.
22.1 What is reproduction?
22.2 Asexual reproduction in bacteria
1. F
2. T
3. T
4. F
1. During asexual reproduction, the parent organism produces new individuals simply by
4.
mitosis.
In sexual reproduction, the gametes are produced by meiosis / zygote is formed after
fertilisation.
22.3 Asexual reproduction in flowering plants
A.
B.
Plant
Vegetative propagating organ
1.
onion
bulb
2.
ginger
rhizome
3.
potato
tuber
4.
Gladiolus
corm
1.
2.
3.
4.
B
A
D
C
22.4 Sexual reproduction in flowering plants
A. 1. D
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B.
2.
3.
A
H
4.
5.
6.
7.
8.
9.
10.
G
C
B
E
I
J
F
1.
(a) stamens
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(k)
2.
3.
filament
anther
pollen sacs
carpel
ovary
style
stigma
anther
stigma
species
(l) pollen tube
(m) style
(n) ovary
22.5 Fruits and seeds
22.6 The advantages and disadvantages of sexual reproduction compared with asexual
reproduction in flowering plants
Structure
Name
Function
A
seed coat
protects the embryo
B
cotyledon
provides stored food for seed germination
C
plumule
grows and develops into the leafy shoot
D
radicle
grows and develops into the root
22.7 Sexual reproduction in humans
A. 1. (a) testis
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2.
3.
(b) sperm ducts
(c) penis
4.
5.
(d) epididymis
(e) seminal vesicles
(f) prostate glands
(g) Cowper's glands
6. (h) scrotum
7. (i) urethra
8. (j) ovary
9. (k) oviduct
10. (l) uterus
B.
11. (m)
vagina
12. (n) cervix
1. 1. D
2. E
3. C
4. B
5. F
6. A
2. 1. C
2. A
3.
4.
5.
D
E
B
22.8 Human embryos
1. T
2. F
3. F
4. T
5. F
2.
3.
5.
6.
6. F
7. T
Fertilisation usually occurs in the oviduct.
Implantation takes place in the uterus.
The foetus obtains nutrients from the mother's blood through the placenta.
Pregnancy begins when implantation takes place.
22.9 The birth process
(c) → (b) → (a) → (d)
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22.10 Parental care
1. F
2. F
3. T
1. During pregnancy, the mammary glands in the mother's breast start to produce milk.
2. In humans, parental care starts from the birth of a baby and lasts very long.
22.11 Birth control
1. condom, surgical method
2. surgical method
3.
4.
5.
6.
7.
8.
surgical method
condom, diaphragm
IUD
natural method
condom, diaphragm
contraceptive pills, IUD, surgical method
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23.1 Growth and development
1. F
1.
3.
5.
2. T
3. F
4. T
5. F
6. T
Mitosis is involved in growth.
Some of the food taken in by an organism is used to release energy.
The processes of growth of plants involve cell division, vacuolation and differentiation.
23.2 Growth and development in humans
1. F
2. T
3. F
4. F
5. F
6. T
1. In humans, when growth stops at the age of about twenty, cell division continues to
occur in the body to replace the worn-out tissues.
3. The reproductive organs are the last organs to develop and differentiate.
4.
5.
Arms and legs grow slowly at the early stage and then speed up in later stages.
From birth to the age of eleven, the patterns of growth of boys and girls are similar.
23.3 Seed germination
1. (a) fresh mass
(b) dry mass
2. (c) starch
(d) cell walls
(e) respiration
(f) protein
3.
(g) amino acids
(h) micropyle
23.4 Growth and development in plants
1. T
2. F
3. F
4. T
5. F
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2.
In a plant, cell division also occurs in other regions such as the stems and roots so that
they can grow thicker.
3.
In plants, the new cells carry out cell elongation before they differentiate into
specialised tissues.
Annual plants complete their life cycles in one growing season.
5.
23.5 Measurement of growth
Advantage
most accurate method
Measuring method
●
●
size
Disadvantage
●
● kills the organisms
does not take into
●
●
fresh mass of a plant
●
● account of the growth
in other dimensions
quick and more reliable ●
●
dry mass
●
● you have to uproot it
quick and easy
24.1 What is genetics?
1. (a) heredity
(b) variation
(c) genetics
24.2 Genes and inheritance
1. (a) homologous
2. (b) DNA
(c) deoxyribose sugar
(d) phosphoric acid
(e) double helix
(f) organic bases
3. (g) alleles
24.3 The pattern of inheritance
A. 1. D
2.
3.
4.
5.
6.
7.
8.
9.
B. 1.
E
A
H
B
I
C
F
G
C
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2.
3.
New Biology — a modern approach
D
A
4. C
24.4 Variations
1. C
2. C
3. D
4. B
24.5 Inherited disorders in humans
1. D
2. A
24.6 Genetic engineering
1. F
2. F
3. T
4. F
1. Genetic engineering is a technique of introducing new genes to an organism from other
different organisms.
2.
4.
Producing GM foods is one of the applications of genetic engineering.
Some of the vegetables that we eat every day are GM plants.
25.2 Evidences for evolution – fossil records
1. T
2. F
3. F
4. T
5. T
6. F
2.
3.
6.
Dinosaurs once existed but are now extinct. Ferns still exist now.
All animals on Earth were not appeared at the same time.
The fossil Archaeopterynx shows that reptiles and birds may have evolved from a
common ancestor.
25.3 General plan and functions of the human skeleton
1. T
2. F
3. T
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2.
4.
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4. F
Darwin discovered that variation occurred between individuals of the same species.
The survivors can reproduce (sexually) and pass on the favourable characteristics to
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