sci focus 2 hb answers

Science Focus 2 Homework Book Answers Pearson Education Australia (a division of Pearson Australia Group Pty Ltd) 2005. This page may be photocopied for classroom use.

Carls new experiments1.1A N S W E R S

Answers to worksheets

Key

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Carl's experiments

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1 Qualitative. They were qualitative because all observations were recorded using only words.

2 Carl thought that he should also do a quantitative analysis; that is, record the observations using numbers to measure how much the grass actually grows under different situations.

3 a Controls.b Every experiment needs a control against which results can be compared.

4 Types of grass, amount of grass.

5 The amount of water was kept the same.

6 The amount of sunlight.

7 The amount of water.

8 The soil would have had some water in it on Day 1 and would take a few days to dry out.

9 Measurements to be taken at the same time of day. Same ruler to be used and measured from the same place. Others as appropriate.

10 Repeating measurements is a good way to improve accuracy. Once a collection of different measurements is taken, an average can be obtained.

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b 1A 16 or 17 mm 1B 6 or 7 mm 2C 16 or 17 mm 2D 12 or 13 mm



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 T H E M A R I A N A T R E N C H

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Extreme units1.2A N S W E R S

Graphing skills1.3Answers to worksheets

A N S W E R S

Predicted energy consumption in Australia in 200910

electricity45.2%

other3.3%

solar1.0%

oil0.4%

wood15.3%

natural gas34.9%

Reading number

Blood glucose levels

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2, 3 The greater the height, the lower the graph.

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6, 7 The greater the mass, the higher the graph.

8 a 13b 28.5

9 a high BMIb medium BMIc low BMId medium BMI

10 Various answers, eg:a 1.4 m, 39.2 kgb 1.6 m, 64 kgc 1.8 m, 129.6 kg

Body mass index1.4A N S W E R S

Mass (kg) BMI (1.6 m tall people) BMI (1.8 m tall people)

50 19.5 15.460 23.4 18.570 27.3 21.680 31.3 24.790 35.2 27.8100 39.1 30.9110 43.0 34.0120 46.9 37.0

Height (m) BMI (50 kg people) BMI (60 kg people)

1.2 34.7 41.71.3 29.6 35.51.4 25.5 30.61.5 22.2 26.71.6 19.5 23.41.7 17.3 20.81.8 15.4 18.51.9 13.9 16.6

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Answers to worksheetsA N S W E R S


Unit 1.1: What, why and how?

1 experiment2 micrometer

Unit 1.2: Scientific research

1 research2 observations3 quantitative4 qualitative5 inference6 variable7 hypothesis8 aim9 conclusion

Unit 1.3: Better measurements

1 estimate2 mistake3 error

4 parallax error 5 reading error 6 instrument errors 7 average 8 metric 9 period

Unit 1.4: Scientific conventions

1 conventions 2 apparatus 3 procedure 4 discussion 5 conclusion 6 bibliography 7 data 8 tabulated 9 independent variable10 dependent variable11 line of best fit

Sci-skills crossword1.5

Sci-words1.6A N S W E R S

A N S W E R S





1 Tungsten WSodium NaZinc ZnEinsteinium EsTin SnBoron BCerium CeRadon Rn

2 Am AmericiumUub UnunbiumNe NeonAr ArgonCd CadmiumO OxygenH HydrogenSi SiliconS Sulfur

3 a Radium e Sulfurb Potassium f Heliumc Iodine g Silverd Mercury

4 a 12b Any atoms before carbon on the list, eg

oxygen, heliumc Any atoms after carbon on the list, eg zinc,

silverd Atomic weight generally increasese AW of Mg = 24

AW of C = 1224/12 = 2 times heavier

f AW of He = 4AW of C = 1212/4 = 3 times lighter

5 a Hydrogen, H b Caesium, Cs

The elements2.1A N S W E R S

1 a 99.99 per centb They are averages based on experimental data and are not 100 per cent accurate.

2 Students to colour in diagram.

3 Iron is needed to carry oxygen in our blood from the lungs to all parts of our body.

4 Breathe in, eat them in food, drink them.

Body elements2.2A N S W E R S



Elements wordfind2.3A N S W E R S

G Y M P T N U M N H J G K N D

A R U L U E P U O E N O T O N

L U I U N O E I R L D L I B O

U C D T G N U N O I P D T R R

M R A O S E R I B U O L A A I

I E R N T G O E C M T M N C P

N M M I E O P T A U A U I V L

I A U U N R I S L I S I U E A

U G I M I D U N C N S C M N T

M N M T D Y M I I A I I C I I

L E O I O H D E U R U R O R N

E S R N I T Q D M U M E P O U

A I H C H L O R I N E M P U M

D U C I E M U I R A B A E L X

Q M S K R Y P T O N D P R F B



Element Mass of oxide (g)

Increase in mass (g)

Percentage increase (%)

Atomic number

Reactivity order

Aluminium 190.1 90.1 90.1 13 5Calcium 139.7 39.7 39.7 20 3Copper 124.5 24.5 24.5 29 9Iron 142.9 42.9 42.9 26 7Lead 103.1 3.1 3.1 82 8Magnesium 166.7 66.7 66.7 12 4Potassium 141.8 41.8 41.8 19 1Sodium 175.3 75.3 75.3 11 2Zinc 124.5 24.5 24.5 30 6

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2 The points are scattered all over the graph. This shows no relationship between reactivity and mass increase on reaction.

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4 As atomic number increases there is a decrease in percentage increase in mass.5 The higher the atomic number of the metal, the lower the mass gain on reaction with oxygen6 a Approximately 17 per cent increase in mass.

b Approximately 10 per cent increase in mass.7 a Iron.

b The result was well above the line of best fit and may have been incorrectly weighed.8 a The purity of the reacting metals.

b The surface area of the metal sample.There may be others.

Combination reactions2.4A N S W E R S

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2 The graph is very close to a straight line, sloping upwards as you move right. You can predict the atomic weight by multiplying the atomic number by 2.5, or you could read the atomic weight from the graph.

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4 The graph is cyclical, with several peaks and troughs.

Atomic graphs (extension)2.5A N S W E R S

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2 The number of protons in the nucleus of the elements.

3 Nobelium, Einsteinium, Mendelevium, Lawrencium, Seaborgium, Bohrium, Rutherfordium, Curium, Fermium. There may be others.

4 Lead 82 PbGold 79 AuOxygen 8 OPotassium 19 KSulfur 16 SCarbon 6 CSilver 47 AgIron 26 FeSodium 11 Na

5 9 Fluorine F4 Beryllium Be40 Zirconium Zr13 Aluminium Al94 Plutonium Pu80 Mercury Hg22 Titanium Ti27 Cobalt 2715 Phosphorus P14 Silicon Si

6 a Sodium, Sulfur, Silicon, Selenium, Seaborgium, Scandium, Strontium, Silver, Samarium.b In order as above: Na, S, Si, Se, Sg, Sc, Sr, Sm.c As many elements start with the same letter, a second letter is needed to tell them apart.

7 a Alkaline metals, Alkaline earth metals, Noble gasesb Helium He, Neon Ne, Argon Arc Helium Balloons, blimps

Neon Neon lightsArgon Fluorescent light tubes

The periodic table2.6A N S W E R S



Unit 2.1: Elements, compounds and mixtures

1 element2 symbol3 atom4 molecule5 lattice6 compound7 formula8 mixture

Unit 2.2: Physical and chemical change

1 physical2 chemical3 combination4 reactant5 product6 decomposition 7 precipitate8 arrow9 solid

10 concentration11 area12 catalysis13 enzymes

Unit 2.3: Inside atoms

1 Dalton2 Thomson3 Rutherford4 Bohr5 alpha6 nucleus7 protons8 neutrons9 electrons

10 charge11 atomic12 mass

Atoms crossword2.7A N S W E R S

Sci-words2.8Answers to worksheets

A N S W E R S



1 Microbe size Convert to micrometres (mm X 1000) Convert to nanometres (m X 1000)

3 millimetres 3000 3 000 000

5 millimetres 5000 5 000 000

7 millimetres 7000 7 000 000

5 micrometres 5 000

8 micrometres 8 000

10 micrometres 10 000

2 Microbe name Length or diameter as shown Length or diameter in nanometres

Yeast (fungi) 5 m 5 000

E. coli (bacteria) 3.5 m 3 500

Cholera bacteria 2.5 m 2 500

Filovirus 1 400 nm 1 400

Thiomargarita (fungi) 200 nm 200

Retrovirus 100 nm 100

Cold virus 1.1 nm 1.1

Water molecule 0.3 nm 0.3

3 Thiomargarita (fungi).

4 Thiomargarita (fungi), E. coli (bacteria), yeast (fungi), cholera bacteria.

5 Filovirus, retrovirus, cold virus, water molecule.

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The size of microbes3.1A N S W E R S

cytoplasm

cell membranecell wall

flagellum

protein coat

chemical withinstructions formaking newviruses



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2 Identify the time periods that correspond to each of the four phases: lag phase = 0 to 2 hours log phase = 3 to 8 hours stationary phase = 9 to 12 hours death stage = 13 to 15 hours.

3 a The antibiotic was taken at about the 13th hour of infection. b The number of microbes fell very quickly between hours 13 and 14.

4 If you extended the graph to the 16th hour the number of bacteria would be about 4000.

5 The bodys immune system starts killing the bacteria.

Bacterial growth3.2A N S W E R S



1 Kills most microbes Stops or slows growth of microbes

Pickling Refrigeration

Pasteurisation Freezing

Heating in cans Drying foods

Salting

2 To keep microbes out; to stop microbes infecting the food, making it go off.

3 The frozen peas contain frozen microbes that will reproduce once the peas are defrosted.

4 a The milk goes off because microbes start to reproduce.b This implies that the pasteurisation process does not kill all of the microbes present in milk.

5 Microbes like warm conditions in which to reproduce and grow. At lower temperatures they grow more slowly, as chemical reactions are slower at colder temperatures.

6 Salted meat would last longer as the salt actually kills the microbes. Dried meat would be more easily spoilt, as the bacteria are already there waiting to grow, but the salted meat would need to be reinfected.

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Preserving foods3.3A N S W E R S

Food Preservation method

Cream refrigeration, pasteurisation

Apricots dried, refrigeration, heating and sealing in a can or jar

Fish refrigeration or freezing, pickling, salting

Pasta sauce refrigeration or freezing, heating and sealing in a jar

Potato chips salting, airtight

Pizza base refrigeration

Grapes dried (sultanas), refrigeration

Orange juice refrigeration

Peanuts salting, airtight

Salad refrigeration

Onions refrigeration, pickling

Jam heating and sealing in a jar



Disease Symptoms How do you catch it? What causes it?

Malaria Fever, shivering, headaches Insectmosquito Protozoa

Common cold

Runny nose, sore and dry throat, headache

Air, coughing and sneezing Virus

Mumps Painful swelling of the neck. High fever, headache

Air, coughing and sneezing Virus

Chickenpox Itchy, small red blister all over the body

Contact with infected person Virus

Cholera Diarrhoea, vomiting, dehydration Contaminated drinking water Bacteria

Ring worm Ring-shaped itchy patches Contact with infected person Fungi

Scarlet fever Fine red rash, sore throat, high temperature, vomiting, tongue looks white with red spots

Air Bacteria

Whooping cough

Extended period of coughs ending with a whoop sound

Air, coughing and sneezing Bacteria

Tinea Itchy red patches between toes Contact with infected person Fungi

Disease3.4A N S W E R S

Microbes crossword3.5A N S W E R S


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Unit 3.1: What is a microbe?

1 microorganisms2 formite3 microscope4 electron5 bacteria6 cocci7 flagella8 fungi9 yeast

10 mould11 protists12 cilia13 amoeba14 virus

Unit 3.2: Reproduction in microbes

1 binary2 daughter3 antibiotics4 hyphae5 spore6 sporangium7 budding8 fission9 host

10 antibodies

Unit 3.3: Friend or foe?

1 decomposition2 toxins3 yoghurt4 cheese5 rennin6 truffles7 penicillin8 aerobic9 fermentation

10 carbon dioxide11 yeast 12 athletes foot13 flu




1 100 grams contains

Cereal Energy (kJ)

Protein (g)

Fat(g)

Carbohydrate (g)

Sugar (g)

Fibre (g)

Sodium (mg)

Potassium (mg)

Vita Brits 1510 10.9 2.2 67.6 1.1 11.9 400 n.a.

Weetbix 1390 12 1.3 67 2.8 11 280 340

Weeties 1520 10.9 2.2 68.0 1.1 12.0 405 n.a.

Nutri-Grain 1596 21.9 0.6 69.4 32 2.7 600 147

Corn Flakes 1582 7.8 0.2 83.6 7.9 2.6 800 93

Coco Pops 1603 5.4 0.3 87.7 36.5 1.2 564 243

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Analyse this!page 14.1A N S W E R S

1650

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3 a All contained similar amounts of energy, though Nutri-Grain, Corn Flakes and Coco Pops contained the most (about 1600 kJ).

b Nutri-Grain stands out as containing the most protein (21.9 g per 100 gabout double all the others).

c All contained low amounts of fat, but Vita Brits and Weeties contained most (2.2 g per 100 gabout triple that of the others).

d Corn Flakes and Coco Pops contained the most carbohydrate (about 85 g per 100 g).e Vita Brits and Weeties contained almost no sugar compared with the others, while Nutri-Grain

and Coco Pops were made up of about one-third sugar.f Vita Brits, Weetbix and Weeties contained most fibre (about 12 g per 100 g).g Corn Flakes stand out as containing most sodium (800 mg per 100 g).h Weetbix contained most potassium (340 mg per 100 g).

4 a Vita Brits and Weeties are low in sugar and high in fibre.b Coco Pops and Nutri-Grain are high in sugar and low in fibre.

5 Various answers depending on student response.6 Various answers depending on student response.

Analyse this!page 24.1A N S W E R S

Sodium (mg)

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1 See Figure 4.2.5 in Science Focus 2.

2 a Produces enzymes that aid in digestion.b Digests food through chemical and mechanical processes.c Cut and grind food.d Absorbs minerals and water from food.e Stores glucose, detoxifies blood.f Helps manipulate and push food back for swallowing.g Produces saliva.h Stores bile, which helps digestion of fats.i Absorbs protein, carbohydrates and lipids from food. Most digestion occurs here.j Pushes food from mouth to stomach.

3 a Large intestine.b Pancreas.c Small intestine.d Rectum.e Mouth.

The human circulatory system


4.4A N S W E R S

The human digestive system4.2A N S W E R S



3 The left side pumps blood to the entire body and must work harder than the right, which just pumps to the lungs.

The heart


4.3A N S W E R S






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2 The brain.

3 The muscles.

4 a 5800 mL/min b 17 500 mL/min

Blood flow rates4.5A N S W E R S

Blood flow

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Abdomen Brain Heart Kidney Muscles Skin Other

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During strenuous exercise

1 See Figure 4.4.3 in Science Focus 2.2 a The blood.

b Body wastes, including excess water and salts, and urea.

3 Kidneys, ureters, bladder, urethra.

4 The urinary system acts like a filter. Blood flows through the kidneys and is cleaned, so that useful substances are kept in the blood and the wastes are removed into the urine. It also ensures that the amount and composition of body fluids are kept at levels that are safe.

The urinary system4.6A N S W E R S





2 Triggers include dust, smoke, irritants, chemicals and exercise.

3 The airways become narrower. This is caused by the contraction of the airway muscles with swelling and inflammation of the airway lining. This then leads to the production of excess mucus, which further restricts airflow. The result is a reduced amount of air going in and out of the lungs.

4 Wheezing, chest tightness, breathlessness and sometimes coughing.

5 Reliever and preventer medication.

6 A reliever relaxes the muscles of the airway, allowing them to open and produce normal breathing. A preventer reduces swelling and inflammation of the airways, which helps reduce excess mucus production.

7 The normal airways are open, not inflamed or irritated, and produce a little bit of mucus.The asthma sufferer would have a swollen, inflamed lining that may be producing excess mucus, even between attacks.

Asthma4.7A N S W E R S

1 These organisms are too large to allow gases to move directly from the atmosphere to all body cells.

2 The movement of gases across the lining requires a moist surface.

3 a Large surface area and moist surface.b Insectoxygen moves directly from the air to the tissues; fishoxygen moves from water into the

bloodstream.c Large surface area and moist surface.

Other respiratory systems4.8A N S W E R S



Unit 4.1: Food1 dehydration2 water3 lipids4 proteins5 vitamins6 minerals7 carbohydrate8 deficiency9 thiamine

10 potassium11 energy12 nervosa13 bulimia14 obese

Unit 4.2: Digestion1 molars2 incisors3 enamel4 decay5 fluoride

6 alimentary7 bolus8 oesophagus9 peristalsis

10 villi11 caecum12 anus13 rectum14 liver15 sphincter16 chyme17 poisons18 stool19 flatus20 glycogen21 diarrhoea22 vomit

Unit 4.3: Blood and circulation1 plasma2 fibrin

3 transfusion4 artery5 aorta6 capillary7 oxygenated8 atrium9 ventricle

10 valves11 systolic12 pacemaker13 vein

Unit 4.4: Excretion: getting rid of wastes1 excretion2 urea3 water4 kidney5 nephron6 urine7 ureter

8 urethra9 bladder

10 dialysis

Unit 4.5: Respiratory systems1 respiration2 glucose3 carbon dioxide4 enzymes5 metabolism6 anaerobic7 lactic acid8 ethanol9 fermentation

10 windpipe11 alveoli12 epiglottis13 haemoglobin14 diaphragm15 exhaled air16 capillaries

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Body systems crossword4.9A N S W E R S





1

2 Hot, dry windy weather.

3 The contact between your clothes and the seats surface causes the build-up of static electricity through frictional or contact charging.

4 One surface ends up with more negative charges (your body) and the other surface has more positives (the car).

5 Normally 10 000 V but up to 20 000 V.

6 Any one of the following: changing the surface materials of the car seat changing the type of material in your clothing; some materials, however, such as woollen jumpers

and pants, certain human-made fabrics and plastic raincoats, make the effect worse always going barefooted, so the charge will leak away when you step outside the carnot good in

winter! covering your car seats with a conductor such as aluminium foilthis stops the contact-charging

effect before you get out of the car, touching something metal or glass, which may be enough to take the

charges away without the zap.

7 Your shoes insulate you. Removing them allows the charge to leak out.

8 Trampoline.Carpet in a house.Taking a hat on and off.Taking clothing on and off. Others as suggested by students.

9 Various answers as suggested by students.

Zapping car doors5.1A N S W E R S




1 An energy source, such as a battery, a conductor (wires) for the electricity to flow through, something to use up the electrical energy such as a globe or motor, a switch to turn the current on and off.



4 Circuit with symbols, as it is faster and requires fewer details in diagrams; also it is 2D not 3D.


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Electrical symbols and circuits5.2A N S W E R S

Electrical current at the footy5.3A N S W E R S

1 Circuit A.

2 More people could enter the ground.

3 Total number = 2 5 = 10 people every minute.

4 Circuit B.

5 There are two ways for the current to go, so more current flows.

6 The gate is twice as wide so will admit 10 people every minute.

7 Resistance is lower (half).

8 All the people (current) would enter at the truck entrance gate.

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B



Appliance Power rating (W)

Power rating (kW)

Time used for

Time used for (hours)

Energy used (kWh)

Cost ($)

Standard globe 75 0.075 36 hours 36 2.7 0.324

Fluorescent light 40 0.04 24 hours 24 0.96 0.1152

Hair dryer 1500 1.5 10 minutes 0.167 0.25 0.03

Fan heater 2000 2 2 hours 2 4 0.48

Iron 750 0.75 30 minutes 0.5 0.375 0.045

Computer 350 0.35 5 hours 5 1.75 0.21

Microwave oven 1200 1.2 15 minutes 0.25 0.3 0.036

Stove 8000 8 30 minutes 0.5 4 0.48

Frypan 1500 1.5 15 minutes 0.25 0.375 0.045

Refrigerator 600 0.6 1 week 168 100.8 12.096

Washing machine 1000 1 1.5 hours 1.5 1.5 0.18

Television 250 0.25 2 hours 2 0.5 0.06

Kettle 1800 1.8 5 minutes 0.0833 0.15 0.018

Cassette player 10 0.01 20 minutes 0.333 0.003 33 0.0004

$14.1196

Electricity costs5.4

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Electricity crossword5.6A N S W E R S


A N S W E R S



Unit 5.1: Static electricity

1 positive2 negative3 neutral4 attract5 repel6 static7 induced8 photocopier9 field

Unit 5.2: Moving electricity

1 voltage2 currrent3 ammeter4 voltmeter5 nichrome6 insulator7 metals8 cell9 battery

10 lithium

11 photovoltaic12 resistance13 argon14 tungsten15 component

Unit 5.3: Using electricity

1 parallel2 series3 transformer4 direct5 alternating





1 A measure of the ferocity, size and impact of the fire.

2 Fuel consumed, rate of spread and heat energy available in the fuel.

3 I = H W R

4 I = kilowatt per metre, H = kilojoule per kilogram, W = kilogram per square metre, R = metres per hour

5 a I = H W R = 4 10 50 = 2000 kW/mEcological impactmedium impact, trees killed, slow recovery of ecosystem.

b I = 4 50 200 = 40 000 kW/mEcological impactextremely high, ecosystem completely destroyed.

6 Lower limit I = H W R 20 = 4 W 5 20 = 20 WW = 1 kilogram per square metreUpper limit

I = H W R 500 = 4 W 5 500 = 20 W W = 25 kilograms per square metre

A sample of the area would need to have between 1 and 25 kilograms per square metre.

7 a More moisture, lower intensity; less moisture, higher intensity.

b Higher wind, higher intensity, as the wind supplies more oxygen and keeps fire moving faster.

c Fires burn faster and hotter when travelling uphill than down. Sheltered areas may burn at lower intensity than open, exposed areas.

Bushfire intensity6.1A N S W E R S

1 Huntsman spider and mermithid worm.

2 An organism that lives in or on another.

3 Either directly or via food.

4 Body fluids, digestive glands, gonads, muscles.

5 By bursting out of its body.

6 Weakened.

7 a To water.b Possibly thirst.c The worm is aquatic, so its chances of survival are increased.

Whodunnit?6.2A N S W E R S



1

2 a 71.76 kgb 66.04 kgc 53.56 kg

3 a Steady decrease.b Initial increase, then steady.

4 Possibly plastic being used to replace glass containers.

5

6 a 133.64 kgb 127.92 kgc 190.84 kg

7 Various answers, eg paper used in non-packaging steadily increases.

8 1994: 205.40 kg, 1999: 193.96 kg, 2004: 244.40 kg

9 Packaging and non-packaging totals show different trends. The vertical scale for non-packaging involves values around three times larger than those for packaging.

A load of garbage6.3A N S W E R S

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Rabbit advance6.4A N S W E R S



1

2 Various answers, eg cattle grazing, land clearing, food for rabbits and other introduced species.

3 Various answers depending on student research.

Total numbers of rare or threatened Australian plants in all conservation categories

29

78

4017

28

7141

4627

48

9

45

34

16

73 133

154

73

19

128 152

51

35150 237

3530

14

1831

44

16245

774

28

24 128 209

8257

86 85

3715

132316

42

2756

6348

74

66

27

5 3

47

32

76

15

63

27

34

78

250

30

150

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62

99

125

197

435

452480

308

419

464

51100

101200

201400

401 +

4274

150

Threatened plants6.5A N S W E R S




Unit 6.1: Ecosystems

1 ecosystem2 community3 terrestrial4 aquatic5 biosphere6 biomes7 habitat8 microhabitat

Unit 6.2: Physical attributes of an ecosystem

1 environment2 adaptations3 abiotic4 photic zone5 pH6 biotic7 competition

8 dispersal9 predation

Unit 6.3: Food chains and food webs: interactions of life

1 glucose2 photosynthesis3 producer4 autotroph5 consumer6 heterotroph7 carnivore8 omnivore9 herbivore

10 food chain11 food web12 biodiversity13 organic matter

14 decomposers15 mutualism16 commensalism17 parasitism

Unit 6.4: Effects of human civilisation on the ecosystem

1 pollutant2 global warming3 acid rain4 transpiration5 overgrazing6 deforestation7 exotic species8 conservation

Ecology crossword6.6A N S W E R S

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1 A push and a pull force.2 a Evaporation: Change of

state of water from liquid to gas.

b Transpiration: Evaporation of water from a plant.

c Stomata: Hole in the leaf that allows a water and gases in and out.

3 See Figures 7.1.2 and 7.1.4 in Science Focus 2.


5 Strong attractions between water molecules that make them stick together.

6 The Sun.

7 The water in the straw should be higher than the water in the glass.

8 Fill a glass above the rim and observe the curved surface. This is due to the cohesion forces between water molecules.

9 There is a push and pull force involved. Pressure in the roots pushes water upwards. The force of this push can take water about two to three metres. Evaporation of water from the leavescalled transpirationpulls the water molecules up the tree. As

molecules evaporate they attract the molecules around them, as there are strong attractions between water molecules that make them stick together. This creates a small suction force and pulls water upwards. The attraction chain continues to the ground and causes the water to move from the roots to the tree top. Capillary action also helps. As the xylem is a tube, water molecules are attracted to and rise up the walls of the tube a little.

Water movement in trees7.1A N S W E R S

The effect of temperature on photosynthesis

7.2A N S W E R S

1 a Carbon dioxide, water.b Glucose (sugar), oxygen.c Light, chlorophyll.

2 a 6CO2 + 6H

2O

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b A lighted splint will flare when placed in the oxygen gas.

3 a The rate of most chemical reactions increases as the temperature increases.

b At these higher temperatures the enzymes involved in photosynthesis are altered (denatured). Without effective enzymes, the rate of reaction slows.

4 Carbon dioxide level and light intensity. 20 30 40

50

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Temperature (C)


chlorophyll



All organisms require energy to carry out their life functions. The Sun is the ultimate source of energy for all life on Earth.

During photosynthesis plants use the energy from the Sun to make food. Photosynthesis is a chemical reaction in which water and carbon dioxide react to form oxygen and glucose. Glucose is the chemical in which the energy is stored. Chlorophyll is a pigment in plants that absorbs the sunlight. The chlorophyll is contained in structures called chloroplasts inside the leaf cells.

This stored energy is available to be used later. The energy in glucose is released in a process called respiration. Both plants and animals release energy in this way.

In respiration, glucose reacts with oxygen to form the products carbon dioxide and water.

Respiration and photosynthesis would occur very slowly without enzymes to act as catalysts and speed up the reactions.

2 a Photosynthesis:Light

water + carbon dioxide oxygen + glucoseb Respiration:

oxygen + glucose water + carbon dioxide (+ energy)

3 a B b A4 a Oxygen.

b The rate of gas production would increase, as more light increases the rate of photosynthesis.

c Insert a glowing splint and it should burst into flames.

5 a Carbon dioxide.b Insert alighted splint and it should go out (or

limewater test).c Yes.d Oxygen from photosynthesis, as the set-up

is now in the light. And carbon dioxide, as respiration goes on all the time.

Photosynthesis and respiration7.3A N S W E R S


2 mesophyll cells loosely packed cells that give this part of the leaf a spongy appearance;

loose packing allows large spaces for gases to move between the cells

phloem cells carries food and glucose away from the leaf

air space spaces in the leaf where gases move around cells

lower epidermal cells transparent layer of cells on the bottom of the leaf that act like a skin

upper epidermal cells transparent layer of cells on the top of the leaf that act like a skin

cuticle waxy waterproof layer that reduces loss of water from the leaf

stomata small openings on the leaf surface

xylem cells supplies water to the leaf

palisade cells this layer is tightly packed and contains large numbers of chloroplasts; a large amount of photosynthesis occurs here

chloroplast structure in plant cells that contains the green chlorophyll

guard cells cells that change the size of the stomatal openings, allowing stomata to open and close

Leaves7.4A N S W E R S


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Unit 7.1: Plant transport systems

1 glucose2 starch3 photosynthesis4 xylem5 phloem6 vascular7 minerals8 flaccid9 turgid

10 cambiam

Unit 7.2: Photosynthesis and respiration

1 oxygen2 carbon dioxide3 chlorophyll4 chloroplasts5 iodine6 cellulose7 light reaction

8 respiration 9 enzymes

Unit 7.3: Leaves

1 cuticle2 stomata3 xylem cells4 phloem cells5 palisade cells6 mesophyll cells7 epidermis8 guard cells9 green

Plants crossword7.5A N S W E R S





1 Planet Astronomical distance (AU) Bodes Law

Mercury 0.39 0.4

Venus 0.72 0.7

Earth 1.0 1.0

Mars 1.52 1.6

Unknown planet? 2.8

Jupiter 5.2 5.2

Saturn 9.6 10.0

2 The discovery of Uranus provided proof that Bodes Law was correct and other scientists would more strongly believe it.

3 Astronomers thought that the asteroids were fragments of a larger planet that had exploded.

4 Planet Astronomical distance (AU) Working Bodes Law

Uranus 19.2 Align equals signs in following lines 192 + 4 = 196 196/10 = 19.6 AU

19.6

Neptune 30.1 384 + 4 = 388 388/10 = 38.8

38.8

Pluto 39.6 768 + 4 = 772 772/10 = 77.2

77.2

5 There is a large inaccuracy in the last two results. Bodes Law does not seem to work in these cases.

6 Bodes Law holds for the first seven planets only. A law must hold for all cases; therefore Bodes Law is not a true law. The large error in the results for the last two planets showed that the law was a mathematical coincidence only.

Discovering the asteroid belt8.1A N S W E R S



Common name

Constellation Scrambled Clue Unscrambled

AQUARIUS RATEW RIRECAR A bucket is also one WATER CARRIER

AQUILA LEGEA Powerful bird EAGLE

ARA RATLA Found in a church ALTAR

BOOTES SAMNERDH Looks after herds HERDSMAN

CANCER ABCR Sea creature with exoskeleton

CRAB

CANIS GOD Common pet DOG

CAPRICORNUS TOAG Horned animal GOAT

CENTAURUS TENRACU Half-human, half-horse CENTAUR

CETUS AHELW Large aquatic mammal WHALE

COLUMBA VEDO Bird of peace DOVE

CORVUS RWOC Black bird CROW

CRATER UPC Drinking vessel CUP

CRUX SROCS On the Australian flag CROSS

CYGNUS SNAW The ugly duckling was one

SWAN

DELPHINIUS PINHOLD Intelligent sea mammal DOLPHIN

DORADO WORDSHISF Type of fish SWORDFISH

DRACO ARDNOG Medieval beast DRAGON

FORNAX ACENURF Oven FURNACE

GEMINI NITSW Born together TWINS

GRUS RANEC Lifting device or bird CRANE

HYDRA TARWE SONTREM Type of monster WATER MONSTER

HYDRUS ESA PENTERS Ocean-going snake SEA SERPENT

LEO LINO King of beasts (Africa) LION

LEPUS RAHE Like a rabbit HARE

LIBRA SASECL For measuring mass SCALES

MONOCEROS NINROCU Mythical horned horse UNICORN

MUSCA LYF Annoying insect FLY

ORION RENTUH Seeks animals HUNTER

PAVO PECKACO Bird that displays blue and green colours

PEACOCK

PEGASUS DINGWE ROSEH Flying thoroughbred WINGED HORSE

PICTOR TINREAP Artist PAINTER

PISCIS AUSTRINUS NERTHOUS HISF Fish from the south SOUTHERN FISH

SAGITTARIUS HERARC Uses bow and arrows ARCHER

SCORPIUS POONIRCS Stinging arthropod SCORPION

TAURUS ULLB Male cow BULL

TRIANGULUM AUSTRALE

HTOSNREU GIANRELT Three-sided shape in the south

SOUTHERN TRIANGLE

TUCANA CANOUT Tropical bird with large beak

TOUCAN

URSA AERB The grisly is one BEAR

VOLANS NYILGF IFHS Fish that flies FLYING FISH

Constellations8.2A N S W E R S






3 The three main areas are the bulge, the disk and spiral arms, and the halo.

4 Elliptical galaxies have a bulge and a halo, but do not have a disk or spiral arms.

5 The bulge is about 10 000 light years in diameter and contains mostly old stars, gas and dust.

6 The halo contains either individual or clusters of old stars, called globular clusters.

7 Bulge = 1 cm, disk = 10 cm, halo = 13 cm

Parts of a galaxy8.3A N S W E R S

Global positioning8.4A N S W E R S

1 Celestial navigation is the finding of a position on Earth by observation of the Sun, moon, stars and planets.

The celestial sphere is an imaginary hollow sphere with an imaginary centre at the centre of the Earth.

2 G = Global, P = Positioning, S = System.

3 A constellation is group of stars. Celestial bodies are objects in the night sky. The human-made celestial bodies are the satellites. This phrase therefore describes the group of satellites orbiting the Earth.

4 NAVSTAR could mean navigation by the stars (these stars being satellites). The actual meaning of NAVSTAR is NAVigation System by Timing And Ranging.

5 Positional accurately to within metres.

6 The satellites orbit at 20 000 kilometres. The 24 NAVSTAR satellites are in different orbital planes. This provides global coverage for the GPS.

7 Three satellites will give a latitude/longitude position. This is called a 2D position fix. With four or more satellites, you get a 3D position which includes latitude, longitude and altitude.

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Unit 8.1: Space rocks

1 astronomy2 asteroid3 comet4 meteor5 meteorite6 meteoroid7 Halley8 tails9 Ceres

Unit 8.2: The night sky

1 light year2 sphere3 ascension4 declination

5 constellation6 Crux7 Centauri8 Hadar

Unit 8.3: The Milky Way and other galaxies

1 galaxy2 spiral3 Milky Way4 quasar5 radio6 AAT7 Hubble8 universe

Unit 8.4: Satellites and remote sensing

1 satellite2 asynchronous3 polar4 Positioning5 meteorology6 false7 Spirit

Sci-words


8.6A N S W E R S

Astronomy crossword8.5A N S W E R S


Solids, liquids and gases crossword1.1A N S W E R S



Unit 9.1: Teamwork and topics

1 scientific research2 explorer3 scientist4 team player5 researcher6 open-ended

Unit 9.2: Planning your investigation

1 research2 variables3 independent4 dependent5 controlled6 aim7 hypothesis8 procedure9 replicating

Unit 9.3: Testing and evaluation

1 quantitative2 qualitative3 discussion4 graph5 conclusion6 bibliography

Team research project crossword9.3A N S W E R S


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sci focus 2 hb answers

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