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Attnom Academy assessment paper, Level 4

Science, about class 10

Time: 60 minutes
40 marks
25 questions

This paper tests only the chapters below. Read them first. Each question names its chapter in the mark scheme, so a lost mark tells you what to read again.

S4.1 Cells, photosynthesis and respiration
S4.2 Genes and inheritance
S4.3 Evolution and ecology
S4.4 Health, disease and immunity
S4.5 Nerves, hormones and balance
S4.6 Atoms, bonding and the periodic table
S4.7 Reactions, equations and amounts

Sit it here and mark it on this device, or print it on A4 with its mark scheme. The class is a guide: the books are written in levels.

Section A. Quick recall (16 marks)

Tick one answer for each question. Each question is worth 1 mark.

Question 11 mark

In a school laboratory, a teacher mixes an enzyme from the gut with starch at 37 °C, and the starch breaks down. The teacher boils a second sample of the enzyme, cools it back to 37 °C and adds starch. Nothing breaks down. Why?

ABoiling used up the enzyme, as heat burns up a fuel.

BBoiling changed the shape of the active site, so the starch no longer fits.

CCooling it back to 37 °C slowed the enzyme too much.

DBoiling killed the enzyme, because an enzyme is a living thing.

Question 21 mark

On a cold morning at 2 °C, a leaf sits in full sun. The air around it has plenty of carbon dioxide. The leaf makes glucose only slowly. What limits the rate of photosynthesis?

ALight, because the Sun is too dim at that time.

BCarbon dioxide, because cold air has none in it.

COxygen, because the leaf needs it to make glucose.

DTemperature, because the enzymes in the leaf work slowly in the cold.

Question 31 mark

In pea plants, the allele for purple flowers, P, is dominant. The allele for white flowers, p, is recessive. Mei has a plant with purple flowers. Which statement must be true?

AIt has at least one P allele.

BIts genotype is PP.

CIt has one P allele and one p allele.

DBoth of its parents had purple flowers.

Question 41 mark

Kofi measures two features of 30 plants of one kind in a school garden. The first is the length of each plant's longest leaf, in cm. The second is whether its flowers are red or white, with nothing in between. Which statement is correct?

ABoth features show continuous variation.

BBoth features show discontinuous variation.

CLeaf length shows continuous variation, and flower colour shows discontinuous variation.

DLeaf length shows discontinuous variation, and flower colour shows continuous variation.

Question 51 mark

A gene in one person has one base swapped for another. The same gene in another person has one extra base added near its start. Which change is more likely to stop the protein from working?

AThe swap, because a swap always gives a different amino acid.

BThe extra base, because it shifts every group of three after it.

CNeither, because a change in DNA never changes a protein.

DBoth equally, because each changes the gene by only one base.

Question 61 mark

A field floods and stays under water for weeks. The soil has very little oxygen, and the nitrate in it falls. Which bacteria cause the loss, and what do they make?

ADenitrifying bacteria, which turn nitrates into nitrogen gas.

BNitrifying bacteria, which turn nitrates into ammonium.

CNitrogen fixing bacteria, which turn nitrates into proteins.

DDecomposers, which turn nitrates into carbon dioxide.

Question 71 mark

Two kinds of fish in a lake eat the same small insects. A hot, dry summer halves the number of insects. What is most likely to happen to the fish?

ANothing changes, because heat is a non living factor and fish are living things.

BThe two kinds of fish stop competing, because there are fewer insects.

CBoth kinds of fish rise, because the heat makes fish grow faster.

DThey compete harder for the fewer insects, so each kind may fall in number.

Question 81 mark

A new road cuts a forest into two parts. Deer on one side can no longer reach deer on the other side. Which plan helps the deer most?

AA seed bank that stores seeds of the forest trees.

BA fence along both sides of the road, all the way along.

CA bridge planted with trees over the road, joining the two parts.

DClearing a wide strip beside the road, so drivers see the deer.

Question 91 mark

Years ago, a person breathed in the tuberculosis bacterium but did not become ill. The person now has HIV, has not yet started treatment, and has had a cough for weeks. What is the most likely cause of the cough?

AThe bacteria slept in the body and woke as the defences weakened.

BHIV has slowly turned into the tuberculosis bacterium.

CA mosquito has carried tuberculosis to the person.

DHIV itself grows in the lungs and makes the person cough.

Question 101 mark

Dev took antibiotics from a health worker for chlamydia and finished the course. A test showed that he was cured. His partner felt well and was not tested. Three months later, Dev's test shows chlamydia again. What is the most likely reason?

AChlamydia is caused by a virus, so antibiotics could not cure it.

BHe caught it from a shared cup or a toilet seat.

CThe cure from antibiotics wears off after a few weeks.

DHis partner had the infection with no signs, and passed it to him again.

Question 111 mark

A rare illness stops a person's pancreas making glucagon. Insulin still works. When is the person most at risk of blood glucose that falls too low?

ASoon after a large sweet meal, when glucose has just entered the blood.

BMany hours after the last meal, when the liver must release glucose from its store.

CSoon after drinking water, when the blood is more dilute.

DWhile eating a meal, when insulin is released and cells take in glucose.

Question 121 mark

Tariq has a rare illness. His pituitary gland does not release any ADH. What does his urine look like, and why?

AIt is small in amount and dark, because the kidneys take back too much water.

BThere is no urine at all, because ADH is needed to make urine.

CIt is large in amount and pale, because the kidneys take back too little water.

DIt is normal, because the kidneys control water without any hormone.

Question 131 mark

A medicine keeps the level of progesterone high all through a cycle. What is it most likely to stop?

AThe lining of the uterus from thickening, because progesterone breaks the lining down.

BOvulation, because progesterone makes the pituitary gland release a surge of LH.

CNothing, because progesterone only matters in the first half of the cycle.

DOvulation, because progesterone holds back FSH and LH, so no egg matures.

Question 141 mark

Neha grows a bean seedling on a sunny windowsill. Every day she turns the pot half a turn. After two weeks the shoot is still nearly straight. Why?

ATurning the pot destroys the auxin, so no side grows longer.

BEach side is shaded in turn, so each side gets extra auxin in turn.

CTurning makes the shoot respond to gravity, so it ignores the light.

DShoots always grow straight up, so light from one side does nothing.

Question 151 mark

Caesium is in group 1, below sodium. Which prediction about caesium is correct?

AIt is more reactive than sodium, because its outer electron is further from the nucleus.

BIt is less reactive than sodium, because its atoms have more electrons.

CIt is less reactive than sodium, because it holds its outer electron more strongly.

DIt is as reactive as sodium, because both have one outer electron.

Question 161 mark

Chlorine gas is made of Cl₂ molecules. Each chlorine atom has 7 outer electrons. How are the two atoms in one molecule held together?

AOne atom gives an electron to the other, so two ions form.

BThey share two pairs of electrons, as the atoms in O₂ do.

CThey share one pair of electrons, so each atom has a full outer shell.

DThey share all 7 outer electrons, so each atom has 14.

Section B. Worked problems (16 marks)

Show your working. Write the answer with its unit. The marks for each question are shown beside it.

Question 172 marks

Kofi takes 15 breaths per minute at rest. One minute after a hard race he takes 36 breaths per minute. What is the percentage increase in his breathing rate?

Your answer and its unit, like 8 m. Work it out on paper.

Question 182 marks

Mei counts oxygen bubbles from a water plant that is lit by a small bare lamp. She moves the lamp from 20 cm to 50 cm from the plant. What percentage of the light reaches the plant now, compared with before?

Your answer and its unit, like 8 m. Work it out on paper.

Question 192 marks

A large study follows 640 children. Both parents of each child are carriers of cystic fibrosis. About how many of the children are expected to be carriers, with no signs of the condition?

Your answer and its unit, like 8 m. Work it out on paper.

Question 202 marks

Dina catches 30 beetles in a garden. She marks each one with a dot of harmless paint and sets them free. Later she catches 40 beetles, and 5 of them have a mark. Estimate how many beetles live in the garden.

Your answer and its unit, like 8 m. Work it out on paper.

Question 212 marks

A trial tests a new medicine for a skin infection. In the medicine group, 48 of the 60 patients got better. In the placebo group, 33 of the 110 patients got better. By how many percentage points is the share who got better higher in the medicine group?

Your answer and its unit, like 8 m. Work it out on paper.

Question 222 marks

A teacher has a mass of 72 kg and a height of 1.60 m. What is the teacher's BMI, to one decimal place?

Your answer and its unit, like 8 m. Work it out on paper.

Question 232 marks

A bell is cast from bronze. This bronze is 78% copper by mass, and the rest is tin. The bell has a mass of 450 kg. How many kilograms of tin are in the bell?

Your answer and its unit, like 8 m. Work it out on paper.

Question 242 marks

A teacher wants to show how surface area changes the rate of a reaction with acid. A cube of chalk has sides of 3 cm. It is cut into small cubes with sides of 1 cm. What is the total surface area of all the small cubes, in cm²?

Your answer and its unit, like 8 m. Work it out on paper.

Section C. A longer question (8 marks)

Each part is about the same factory. Show your working.

Question 258 marks

A factory makes calcium metal. It melts calcium chloride, CaCl₂, and passes an electric current through the liquid. The equation is CaCl₂ → Ca + Cl₂. The relative formula mass of CaCl₂ is 111. The relative atomic mass of calcium is 40.

(a)The factory melts calcium chloride, not calcium oxide. Calcium chloride melts at 772 °C, and calcium oxide at about 2 600 °C. Both are ionic. Why does calcium oxide melt at a much higher temperature? [1 mark]

ACalcium oxide has covalent bonds, which are stronger than ionic bonds.

BAn oxygen atom is heavier than a chlorine atom, so it is harder to move.

COxide ions have a bigger charge than chloride ions, so the ions attract more strongly.

DCalcium oxide is made of small molecules that hold tightly together.

(b)What mass of calcium is made from 222 g of calcium chloride? [2 marks]

Your answer and its unit, like 8 m. Work it out on paper.

(c)A worker suggests heating calcium oxide with coke, which is nearly pure carbon, to get calcium. Use the reactivity series to explain why this will not work. [2 marks]

Your answer

(d)The factory melts the calcium chloride and passes a current through it. Explain why calcium forms at the negative electrode. [2 marks]

Your answer

(e)The factory makes its calcium chloride from hydrochloric acid. Which of these, added to the acid, makes calcium chloride with no gas given off? [1 mark]

ACalcium metal

BCalcium hydroxide

CCalcium carbonate

0 of 29 answered. Your answers stay on this device.

The whole mark scheme, for a teacher or for after you mark

Mark scheme

One line is one mark. A right final answer with no working gets every mark for that part. Lost marks? Read the chapter named under the part.

Question 11 mark

Answer: B. Boiling changed the shape of the active site, so the starch no longer fits.

Heat denatures the enzyme: the active site changes shape, so the starch no longer fits, and cooling does not reverse it.

Tests S4.1.5 Enzymes

Question 21 mark

Answer: D. Temperature, because the enzymes in the leaf work slowly in the cold.

Light and carbon dioxide are plentiful, so the cold is the limiting factor: the enzymes work slowly.

Tests S4.1.6 Photosynthesis

Question 31 mark

Answer: A. It has at least one P allele.

Only a plant with no P allele (pp) has white flowers, so a purple plant has at least one P.

Tests S4.2.5 Dominant and recessive

Question 41 mark

Answer: C. Leaf length shows continuous variation, and flower colour shows discontinuous variation.

A feature that can take any value in a range is continuous. A feature in separate groups is discontinuous.

Tests S4.2.7 Variation

Question 51 mark

Answer: B. The extra base, because it shifts every group of three after it.

An extra base shifts every group of three after it, so many amino acids may change. A swap changes one group at most.

Tests S4.2.8 Mutation and genetic engineering

Question 61 mark

Answer: A. Denitrifying bacteria, which turn nitrates into nitrogen gas.

In waterlogged soil, denitrifying bacteria turn nitrates into nitrogen gas, which goes back to the air.

Tests S4.3.5 The carbon and nitrogen cycles

Question 71 mark

Answer: D. They compete harder for the fewer insects, so each kind may fall in number.

Fish that eat the same food compete, and with less food each kind may fall in number.

Tests S4.3.7 Interdependence

Question 81 mark

Answer: C. A bridge planted with trees over the road, joining the two parts.

A planted bridge is a habitat corridor: the deer can cross, find mates and mix their alleles.

Tests S4.3.8 Biodiversity and people

Question 91 mark

Answer: A. The bacteria slept in the body and woke as the defences weakened.

Tuberculosis bacteria can stay asleep in the body for years and wake up when the defences weaken, as in HIV with no treatment. A health worker can test for and treat both.

Tests S4.4.6 Malaria, HIV and tuberculosis

Question 101 mark

Answer: D. His partner had the infection with no signs, and passed it to him again.

Many STIs show no signs, and a cure does not protect against catching the infection again, so both partners need a test and treatment.

Tests S4.4.8 Sexual health

Question 111 mark

Answer: B. Many hours after the last meal, when the liver must release glucose from its store.

Glucagon makes the liver turn glycogen into glucose when the level falls, so without it the level may fall too low between meals.

Tests S4.5.5 Blood sugar and diabetes

Question 121 mark

Answer: C. It is large in amount and pale, because the kidneys take back too little water.

Without ADH the kidney tubules take back too little water, so a lot of dilute, pale urine is made.

Tests S4.5.6 Temperature and water balance

Question 131 mark

Answer: D. Ovulation, because progesterone holds back FSH and LH, so no egg matures.

A steady high level of progesterone holds back FSH and LH, so no egg matures and there is no ovulation.

Tests S4.5.7 Hormones and the menstrual cycle

Question 141 mark

Answer: B. Each side is shaded in turn, so each side gets extra auxin in turn.

Auxin moves to the shaded side, which changes every day, so both sides grow about the same and the shoot does not bend one way.

Tests S4.5.8 Plant responses

Question 151 mark

Answer: A. It is more reactive than sodium, because its outer electron is further from the nucleus.

Group 1 metals lose their outer electron, and this is easier when it is further from the nucleus, so caesium is more reactive.

Tests S4.6.5 The periodic table

Question 161 mark

Answer: C. They share one pair of electrons, so each atom has a full outer shell.

Each chlorine atom needs 8 − 7 = 1 more electron, so the two atoms share one pair.

Tests S4.6.7 Covalent bonding

Question 172 marks

Answer: 140%

The increase is 36 − 15 = 21 breaths per minute.
Percentage increase = 21 ÷ 15 × 100 = 140%.

Tests S4.1.8 Respiration

Question 182 marks

Answer: 16%

For a small bare lamp, the light on the plant = (old distance ÷ new distance) squared, and 20 ÷ 50 = 0.4.
0.4 × 0.4 = 0.16, which is 16% of the light.

Tests S4.1.7 Testing photosynthesis

Question 192 marks

Answer: 320 children

Two carriers, Ff and Ff, have a child who is a carrier, Ff, with a chance of 1 in 2.
640 ÷ 2 = 320 children.

Tests S4.2.6 Family trees and genetic disorders

Question 202 marks

Answer: 240 beetles

The marked beetles are the same share of all the beetles as 5 is of 40.
Number of beetles = 30 × 40 ÷ 5 = 240 beetles.

Tests S4.3.6 Measuring populations

Question 212 marks

Answer: 50 percentage points

Shares: 48 ÷ 60 × 100 = 80%, and 33 ÷ 110 × 100 = 30%.
The difference is 80 − 30 = 50 percentage points.

Tests S4.4.5 Antibiotics and medicines

Question 222 marks

Answer: 28.1

BMI = mass in kg ÷ height in m ÷ height in m, and 1.60 × 1.60 = 2.56.
72 ÷ 2.56 = 28.125, which is 28.1 to one decimal place.

Tests S4.4.7 Lifestyle and disease

Question 232 marks

Answer: 99 kg

The tin is the rest of the bronze: 100 − 78 = 22%.
22 ÷ 100 × 450 = 99 kg.

Tests S4.6.8 Metals and alloys

Question 242 marks

Answer: 162 cm²

The big cube holds 3 × 3 × 3 = 27 small cubes, each with a surface area of 6 × 1 × 1 = 6 cm².
The total is 27 × 6 = 162 cm².

Tests S4.7.8 Energy changes and rates

Question 258 marks

(a)Answer: C. Oxide ions have a bigger charge than chloride ions, so the ions attract more strongly.

In calcium oxide the ions are Ca²⁺ and O²⁻. The bigger charges attract more strongly, so more energy is needed to melt it.

Tests S4.6.6 Ionic bonding

(b)Answer: 80 g

Moles of CaCl₂ = 222 ÷ 111 = 2 mol. The equation shows 1 mol of CaCl₂ makes 1 mol of Ca, so 2 mol of Ca are made.
Mass of calcium = 2 × 40 = 80 g.

Tests S4.7.7 Electrolysis

(c)Answer: Calcium is above carbon in the reactivity series, so carbon is less reactive than calcium. So carbon cannot take the oxygen away from calcium oxide, and no calcium is made.

Says calcium is above carbon in the reactivity series, so carbon is less reactive than calcium.
Says carbon therefore cannot take the oxygen from calcium oxide, so no calcium is made.

Tests S4.7.6 The reactivity series

(d)Answer: The positive calcium ions are attracted to the negative electrode, because opposite charges attract. There each calcium ion gains two electrons and becomes a calcium atom.

Says the positive calcium ions are attracted to the negative electrode, because opposite charges attract.
Says each calcium ion gains two electrons there and becomes a calcium atom.

Tests S4.7.7 Electrolysis

(e)Answer: B. Calcium hydroxide

Calcium hydroxide is a base, and an acid with a base makes a salt and water only.

Tests S4.7.5 Acids, bases and salts