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. And only combusting (but not respiration) occurs in the motor car to release energy.
C. 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.
5. 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. (h) energy
6. (i) amino acids
B. 1. F
2. T
3. F
4. F
5. F
1. In a carbohydrate molecule, the hydrogen atoms and the oxygen atoms are in the ratio of 2:1.
3. Proteins contain energy. It can be used as fuel when carbohydrate or fat is in shortage.
4. DNA is found in the cells of all organisms.
5. DNA is present in the nucleus
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
I revolving nosepiece
B. 1. G
2. D
3. E
4. C
5. B
6. A
7. I
8. F
9. H
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. cell membrane
2. cytoplasm
3. mitochondria
4. chloroplasts
5. cell wall
6. nucleus
7. vacuole
8. chromosomes
3.5 The cell as a basic unit of life
1. nucleus ® cell ® tissue ® organ ® system ® organism
2. (i) E
(ii) C, D
(iii) D
(iv) A
(v) B
4.1 Metabolism
1. b
2. a
3. b
4. b
5. c
4.3 The nature and properties of enzymes
1. T
2. F
3. F
4. T
5. T
6. T
7. F
8. T
2. Some enzymes may leave the cell and exert their actions outside the cell. (Other enzymes exert their action inside the cell.)
3. Catalase is one of the enzymes that can be found in plant and animal tissues.
7. 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
4.6 Movement of substances across the cell membrane
1. (i) b
(ii) a
(iii) b, c
(iv) b
(v) a
2. (a) √
(b) osmosis
(c) lower
(d) √
(e) not
(f) rise
(g) √
3. (i) (a) higher
(b) lower
(ii) (c) mineral salts
(iii) (d) carbon dioxide
(iv) (e) Oxygen
(f) carbon dioxide
(v) (g) water
(h) higher
(i) lower
(j) selectively permeable
5.2 Classification
1. (a) taxonomy
2. (b) species
(c) common features
(d) interbreed
(e) offsprings
5.6 Kingdom plantae
A. 1. (a) prokaryotes
(b) nucleus
2. (c) saprophytic
(d) parasitic
3. (e) algae
(f) water
4. (g) hyphae
(h) spores
5. (i) mosses
(j) ferns
6. (k) rhizoids
7. (l) Gymnosperms
B. 1. fungi
2. ferns
3. algae
4. prokaryotes
5. mosses
6. gymnosperms
7. flowering plants (angiosperms)
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)
5. birds
6. reptiles, birds
7. mammals
8. birds
9. mammals
10. amphibians
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. F
2. F
3. F
4. T
1. Virus and bacterium are two different kinds of things.
2. 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. community
6. ecosystem
7. ecology
6.2 What is environment?
1. T
2. T
3. F
4. T
5. F
2. 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
7. T
2. The primary consumers are not necessarily larger in size than the secondary consumers.
3. Owl and fox are the rarest organisms in the ecosystem.
5. 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
3. (c) predation
(d) predator
(e) prey
4. (f) parasitism
5. (g) competition
7.2 Human activities and pollution
A. 1. F
2. F
3. F
4. T
5. T
6. F
7. F
8. T
9. T
10. T
1. Rain is naturally acidic, with a pH value around 5-6.
2. The main cause of acid rain is the release of sulphur dioxide and nitrogen dioxide from the combustion of fossil fuels.
3. Carbon dioxide is one of the greenhouse gases that cause global warming.
6. Algal bloom leads to the deoxygenation of water. Fish and other organisms may die of suffocation.
7. Detergents contain added phosphates which encourage algal growth.
B. 1. B
2. F
3. C
4. A
5. G
6. D
7. 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
• destruction of natural habitats
• loss of species / cannot maintain a diversity of species
B. 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.
C. 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. Biodiversity can be used to indicate the ‘biological health’ of a particular habitat.
5. 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. (f) mesophyll
3. (g) stomata
8.3 Investigations to study the requirement for photosynthesis
A. Multiple Choice Questions
1. D
2. C
B. Structured Questions
1. (a) 1 ® 4 ® 3 ® 2
(b) to soften the leaf
to extract chlorophyll/decolourise the leaf
2. (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. The chlorophyll mainly absorbs red and blue light of the spectrum for photosynthesis. Most of the green light is reflected.
3. 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.
4. 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
B. 1. F
2. T
3. F
4. F
5. T
6. T
1. Some of the oxygen produced during photosynthesis is used for respiration. The rest of it diffuses out into the atmosphere.
3. Sucrose can be carried to actively growing regions where it is changed to glucose.
4. 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. phloem
viii. stoma
(b) 1. Gases can diffuse into and out of the leaf easily.
2. Diffusion is faster and more sunlight can be absorbed.
3. to carry water and minerals from the soil to the leaf
4. to carry the product of photosynthesis away from leaf
5. for gaseous exchange, to allow carbon dioxide in the atmosphere to diffuse into the leaf
6. to prevent excess water loss
7. for diffusion of gases
9.1 What is respiration?
1. F
2. T
3. T
4. F
5. F
6. T
7. F
8. T
1. All living cells require energy.
4. The process of burning is different from that of respiration.
5. Burning cannot occur inside a cell even if a sufficient amount of oxygen is present.
7. The reactions of respiration are controlled by enzymes while burning does not involve enzymes.
9.3 The chemistry of respiration
1. F
2. T
3. T
4. F
5. T
6. F
7. T
8. F
9. T
1. Respiration in plants occurs all the time.
4. ATP stores energy for a short period only.
6. ATP is made inside the mitochondria.
8. 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
(h) lactic acid fermentation
B. 1. T
2. F
3. F
4. F
5. T
2. Mitochondria are involved in aerobic respiration only.
3. Skeletal muscles carry out aerobic respiration if sufficient oxygen is available.
4. Mitochondria are present in muscle cells.
10.1 Nutrition
1. T
2. F
3. T
4. F
2. Green plants synthesise organic substances by using simple inorganic substances from their surroundings. Energy is needed in this process.
4. Animals, fungi and most bacteria are heterotrophs.
10.2 The importance of minerals for proper growth in green plants
1. (a) active transport
2. (b) major elements
(c) trace elements
3. (d) proteins
(e) nitrates
(f) small leaves
(g) weak stems
4. (h) chlorophyll
(i) poor growth
(j) 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.