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Term pack

Class 9 Science

Name: ________________________

Skills in this pack

  • The cell and what is inside it
  • Plant and animal tissues
  • Distance, displacement, speed and velocity
  • Motion graphs and the kinematic equations
  • Mixtures, concentration and separation
  • Force and Newton's three laws
  • Work, energy and power
  • Inside the atom
  • How atoms combine, and what a molecule weighs
  • Sound waves
  • Reproduction: how life continues
  • Diversity and classification

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Class 9 Science · 1 of 12

The cell and what is inside it

Name the parts of a plant and an animal cell and say what each does, tell a prokaryotic cell from a eukaryotic one, and use osmosis to explain what happens to a cell in salty water.

Before you start

The parts of a cell, each one named.

1234
  1. 1. The round body with a smaller body inside it — the nucleus
  2. 2. The rod with folded lines inside — a mitochondrion
  3. 3. The large clear space — the vacuole
  4. 4. The stack of folded sheets — the endoplasmic reticulum

The outline round the whole thing is the cell membrane. On a plant cell there would be a stiffer layer of cellulose outside it again, and green ovals of chloroplast among the organelles.

  1. 1.Sort each feature by the kind of cell it belongs to.

    Groups: Prokaryotic cell · Eukaryotic cell

    • Membrane-bound nucleus
    • A typical width of 10 to 100 micrometres
    • Membrane-bound organelles
    • A typical width of 1 to 10 micrometres
    • Genetic material in a bare nucleoid

  2. 2.A Rhoeo leaf peel is mounted in a strong sugar solution. Its cells lose water, yet the outline of each cell stays the same shape. What accounts for that?

    • a) Plant cells cannot lose water through their membranes
    • b) The chloroplasts stiffen and hold the cell out
    • c) The rigid cell wall holds the outer shape while the membrane pulls inwards
    • d) The vacuole refills from the sugar solution as fast as water leaves

  3. 3.What is a plant cell wall built mainly from?

    • a) Starch
    • b) Protein
    • c) Cellulose
    • d) Lipid

  4. 4.Which statement is part of the classical cell theory?

    • a) New cells can form from non-living matter under the right conditions
    • b) Cells are found in animals but not in plants
    • c) New cells arise from cells that already exist
    • d) The tissue, not the cell, is the basic unit of function

  5. 5.Who examined a thin slice of cork in 1665 and gave the little compartments he saw the name we still use? Give the surname.

  6. 6.A piece of potato is left in a 20 per cent salt solution for an hour. What happens to it, and why?

    • a) It swells, because salt is drawn into the cells from the solution
    • b) It shrinks, because salt is drawn out of the cells into the water
    • c) Nothing changes, because the membrane blocks both water and salt
    • d) It shrinks, because water leaves the cells for the more concentrated solution

  7. 7.Sort each structure by whether an animal cell has one too.

    Groups: In a plant cell but not an animal cell · In both a plant and an animal cell

    • Cell membrane
    • Mitochondrion
    • Cell wall
    • Nucleus
    • Chloroplast
    • Large central vacuole

  8. 8.A parent cell divides by mitosis. What comes out of it?

    • a) Two daughter cells with half the parent's chromosome number
    • b) Four daughter cells with half the parent's chromosome number
    • c) Two daughter cells with the parent's chromosome number, genetically identical to it
    • d) Four daughter cells genetically identical to the parent

The cell and what is inside it · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 2 of 12

Plant and animal tissues

Name the three meristems and the permanent tissues they become, match each plant and animal tissue to its job, and tell the joints and muscle types apart by what they do.

Before you start

Three simple permanent tissues, side by side and each one named.

123
  1. 1. Thin walls the whole way round — parenchyma
  2. 2. Corners thickened with pectin — collenchyma
  3. 3. Thick lignified walls — sclerenchyma

Parenchyma is alive and stores food. Collenchyma is alive and bends. Sclerenchyma is mostly dead cells, and it is what makes a coconut husk hard.

  1. 1.What are the pores in a leaf's epidermis called? Give the one word.

  2. 2.Bone and cartilage are both connective tissues. What makes one hard and the other springy?

    • a) Cartilage has a rigid matrix and bone has a jelly-like one
    • b) Bone has a rigid matrix with calcium and phosphorus compounds; cartilage's matrix is soft and jelly-like
    • c) Cartilage is a kind of muscle rather than a connective tissue
    • d) Bone has living cells and cartilage has none

  3. 3.This is a neuron. Tap the part that picks up signals coming from other neurons.

    Write the number of the part.

    1234

  4. 4.What does a ligament join?

    • a) A muscle to a bone
    • b) A nerve to a muscle
    • c) A muscle to another muscle
    • d) One bone to another bone

  5. 5.Put a message's journey through a neuron in order, starting from The dendrites pick the message up from another neuron.

    • The dendrites pick the message up from another neuron
    • The axon terminals pass it on to the next cell
    • The axon carries it away as a long fibre
    • The cell body, which holds the nucleus, takes it in

  6. 6.Which iron-rich protein in the red blood cells gives blood its colour? Give the one word.

  7. 7.How many pairs of ribs make up the human rib cage? Answer with a number.

  8. 8.Sort each type of muscle by whether we control it.

    Groups: Moves when we choose · Moves without our choosing

    • Cardiac muscle
    • Skeletal muscle
    • Smooth muscle

Plant and animal tissues · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 3 of 12

Distance, displacement, speed and velocity

Separate distance from displacement and speed from velocity, work out average speed, average velocity and average acceleration, and say what stays fixed in uniform circular motion.

Before you start

Slide along the track. The starting line sits at 0 and the far end at 100.

020406080100

Positions to the right of the starting line count as positive. A runner who goes out to 100 and comes back to 40 has covered a long path but ended up 40 from where she started.

  1. 1.A cyclist rides round a circular track at a steady 8 m/s. What is happening to her velocity?

    • a) Its direction keeps changing while its magnitude stays fixed
    • b) It falls to zero each time she completes a lap
    • c) Its magnitude keeps changing while its direction stays fixed
    • d) Both its direction and its magnitude stay fixed

  2. 2.A bus covers 15 m in the first second, 15 m in the second and 15 m in the third. What does the chapter call this motion?

    • a) Uniform motion in a straight line
    • b) Non-uniform motion in a straight line
    • c) Uniform circular motion
    • d) Motion with constant acceleration

  3. 3.An athlete runs along the track from O out to A, then turns and comes back as far as B. Tap the bar whose length is the magnitude of her displacement.

    Write the number of the part.

    123

  4. 4.A lorry is doing 72 km/h. What is that in m/s? Answer with a number.

  5. 5.A child on a merry-go-round rides exactly once round the circle and stops where she got on. What is the magnitude of her displacement, in metres? Answer with a number.

  6. 6.Match each quantity to its SI unit.

    • Displacement
    • Average velocity
    • Average acceleration
    • metre
    • metre per second squared
    • metre per second

  7. 7.Sort each quantity by whether stating it takes a direction as well as a number.

    Groups: Number on its own · Number and a direction

    • Average speed
    • Total distance travelled
    • Average velocity
    • Displacement
    • Average acceleration

  8. 8.A runner starts at 0, runs out to the 100 m mark, then turns and runs back 60 m. Which mark is she standing on at the end?

    Mark the line with an X.

    020406080100

Distance, displacement, speed and velocity · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 4 of 12

Motion graphs and the kinematic equations

Read velocity off the slope of a position-time graph and displacement off the area under a velocity-time graph, and use v = u + at, s = ut + ½at² and v² = u² + 2as.

Before you start

The parts of a position-time graph, each one named.

123
  1. 1. The time axis, along the bottom
  2. 2. The position axis, up the side
  3. 3. The position-time line itself

This line is straight and sloping, so the object is covering equal ground in equal times. How steeply it climbs is how fast it is going.

  1. 1.Put the steps for plotting a motion graph in order, starting by drawing two perpendicular axes and marking where they cross as the origin.

    • Mark the values along each axis
    • Plot a point for each pair of readings
    • Choose a scale for each axis
    • Draw two perpendicular axes and mark where they cross as the origin
    • Join the plotted points to make the graph
    • Decide which quantity goes along each axis

  2. 2.A trolley is doing 5 m/s and accelerates steadily at 3 m/s² for 4 s. Use v = u + at. What is its final velocity, in m/s? Answer with a number.

  3. 3.Match each thing you can read off a motion graph to the quantity it gives.

    • The slope of a position-time line
    • The slope of a velocity-time line
    • The area under a velocity-time line
    • The displacement
    • The average velocity
    • The acceleration

  4. 4.A position-time graph comes out as a smooth curve rather than a straight line. What does that say about the motion?

    • a) The velocity is constant and the acceleration is zero
    • b) The object is at rest at a fixed position
    • c) The velocity is changing, so the object is accelerating
    • d) The object moved along a curved path over the ground

  5. 5.A cart starts from rest and accelerates steadily at 2 m/s² for 5 s. Use s = ut + ½at². How far does it travel, in metres? Answer with a number.

  6. 6.On a position-time graph an object is at 30 m at 2 s and at 105 m at 5 s. What is the magnitude of its average velocity, in m/s? Answer with a number.

  7. 7.A car is doing 12 m/s when the driver brakes at a steady −3 m/s² until it stops. Use v² = u² + 2as. How far does it travel while braking, in metres? Answer with a number.

  8. 8.Two objects, A and B, are drawn on one position-time graph. B's line is steeper than A's. What follows?

    • a) B started further from the origin than A
    • b) The two have the same average velocity
    • c) B has the greater magnitude of average velocity
    • d) A has the greater magnitude of average velocity

Motion graphs and the kinematic equations · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 5 of 12

Mixtures, concentration and separation

Tell solutions, suspensions and colloids apart, work out a concentration as a percentage, and choose the right method for pulling a given mixture apart.

Before you start

Three beakers, and what the laser beam does in each of them.

123
  1. 1. Salt in water — the beam crosses unseen
  2. 2. Chalk powder in water — the beam shows, and the powder settles
  3. 3. Milk in water — the beam shows, and nothing settles

Shine the light in from the side and watch from a right angle. The path you can see is light being scattered off particles big enough to scatter it.

  1. 1.Put the steps of growing copper sulfate crystals in order, starting from Warm the water with the solid, stirring, until no more will dissolve.

    • Leave the crystals to dry on a watch glass
    • Filter the hot saturated solution to take out insoluble impurities
    • Cover the filtrate and leave it to cool slowly, undisturbed
    • Filter off the crystals and rinse them with cold water
    • Warm the water with the solid, stirring, until no more will dissolve

  2. 2.Sort each description by the kind of mixture it belongs to.

    Groups: Solution · Colloid · Suspension

    • Particles smaller than 1 nanometre
    • Particles you can see, which settle when left alone
    • Scatters a light beam and yet stays evenly spread
    • Lets a laser beam through with no visible path
    • Particles larger than 1000 nanometres
    • Particles between 1 and 1000 nanometres

  3. 3.Mustard oil and water have settled into two layers in this separating funnel. Tap the layer that comes out of the stopcock first.

    Write the number of the part.

    123

  4. 4.Match each separation method to the mixture it is meant for.

    • Distillation
    • Separating funnel
    • Sublimation
    • Paper chromatography
    • Centrifugation
    • Heavier particles from a lighter liquid
    • A solid that sublimes mixed with one that does not
    • Two immiscible liquids
    • The coloured components of an ink or a dye
    • Two miscible liquids with different boiling points

  5. 5.8 g of glucose is dissolved in water and made up to 200 mL of solution. What is the mass by volume percentage? Answer with a number.

  6. 6.20 g of sugar is dissolved in 80 g of water. What is the mass by mass percentage of the solution? Answer with a number.

  7. 7.Brass is described as a homogeneous mixture of about 80 per cent copper and 20 per cent zinc. What is such a mixture called, and can it be separated physically?

    • a) A suspension, and filtration will separate it
    • b) A compound, and no method of any kind will separate it
    • c) An alloy, and physical methods cannot separate its components
    • d) A colloid, and centrifugation will separate it

  8. 8.A talcum powder is 4 per cent zinc oxide by mass. How much zinc oxide is there in 300 g of the powder, in g? Answer with a number.

Mixtures, concentration and separation · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 6 of 12

Force and Newton's three laws

Add forces to find the net force, use F = ma and F = mg, say what Newton's three laws claim, and treat two connected objects as one system.

Before you start

Two everyday situations, and the forces acting in each.

12
  1. 1. A box being pushed along a floor — your push one way, friction the other
  2. 2. A ball floating on water — gravity down, buoyancy up

In each case two forces oppose each other. If they match, nothing changes; if they do not, the leftover is the net force.

  1. 1.Boxes of 3 kg and 5 kg are joined by a string and pulled along a frictionless floor by a force of 16 N. What is the acceleration of the pair, in m/s²? Answer with a number.

  2. 2.Which pair of forces is a Newton's-third-law pair?

    • a) The foot pushing the ground backwards and the ground pushing the foot forwards
    • b) The weight of a book and the table's upward push on that same book
    • c) The forward pull of two people pushing one stalled car
    • d) The push of a hand on a box and the friction on that same box

  3. 3.What is the gravitational force the Earth exerts on a 5 kg bag, in N? Answer with a number.

  4. 4.A 1500 kg car accelerates at 2 m/s². What net force is acting on it, in N? Answer with a number.

  5. 5.A block has 14 N acting on it to the right and 6 N to the left. What is the magnitude of the net force, in N? Answer with a number.

  6. 6.Match each of Newton's laws to what it claims.

    • Newton's first law
    • Newton's second law
    • Newton's third law
    • The acceleration is the net force divided by the mass
    • A force on one object is met by an equal and opposite force on the other
    • An object keeps its rest or its constant velocity until a net force acts

  7. 7.Two boxes joined by a string are pulled to the right by one force. Tap the place where the force acting is internal to the system, and so drops out when the two boxes are treated as one object.

    Write the number of the part.

    1234

  8. 8.Sort each situation by whether the forces acting are balanced.

    Groups: Balanced forces · Unbalanced forces

    • A stalled car set moving by two people pushing
    • A tug of war in which both teams pull equally hard
    • A book lying still on a table
    • A rope moving towards the team that pulls harder

Force and Newton's three laws · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 7 of 12

Work, energy and power

Work out work done, kinetic energy, potential energy and power, say when work is positive, negative or zero, and explain what a pulley, a ramp and a lever actually change.

Before you start

The parts of a lever, each one named.

1234
  1. 1. The load, the weight to be lifted
  2. 2. The fulcrum, the fixed point the bar turns about
  3. 3. The effort, the push you apply
  4. 4. The load arm, from the load to the fulcrum

Put the fulcrum close to the load and the effort arm becomes long. A small push over a long distance then lifts a large load through a short one.

  1. 1.A force of 25 N moves a crate 4 m along the direction of the force. How much work is done on the crate, in J? Answer with a number.

  2. 2.A goalkeeper applies 200 N to a ball while her hands move back 0.15 m, so the ball's displacement opposes her force. How much work does she do on the ball, in J? Include the minus sign.

  3. 3.Put the working of a slingshot in order, starting from The elastic band is pulled back, and work is done on it.

    • The band returns to the shape it started in
    • The stone gains kinetic energy and shoots forward
    • The elastic band is pulled back, and work is done on it
    • The band is let go and pushes on the stone
    • The stretched band holds that work as stored energy

  4. 4.A machine raises a load of 300 N when an effort of 100 N is applied. What is its mechanical advantage? Answer with a number.

  5. 5.Sort each case by the work the named force does on the named object.

    Groups: Positive work done on the object · Negative work done on the object · No work done on the object

    • A boy pushing a wheelchair forward
    • A goalkeeper stopping a moving ball
    • A person pushing hard on a rigid wall
    • A girl slowly lowering a dumbbell
    • Friction acting on a sliding stack of coins

  6. 6.A student pushes as hard as she can against a rigid wall for a minute and gets tired. How much work has she done on the wall?

    • a) It cannot be worked out without knowing her mass
    • b) None, because the wall did not move
    • c) A small amount, because the wall moved a tiny distance
    • d) A large amount, because she applied a large force

  7. 7.A vehicle's speed doubles. What happens to its kinetic energy?

    • a) It becomes twice as large
    • b) It becomes four times as large
    • c) It becomes eight times as large
    • d) It stays the same

  8. 8.A book of mass 2 kg is raised 1.5 m above the floor. Taking g as 10 m/s², what is its potential energy, in J? Answer with a number.

Work, energy and power · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 8 of 12

Inside the atom

Count protons, neutrons and electrons from an atomic number and a mass number, fill the shells and read off a valency, and say what makes two atoms isotopes.

Before you start

The parts of an atom, each one named.

1234
  1. 1. The centre
  2. 2. The nearest ring
  3. 3. The middle ring
  4. 4. The furthest ring

The centre is the nucleus, holding the protons and neutrons. The rings are the shells, filled from the inside out: K first, then L, then M.

  1. 1.An atom of atomic number 26 has 56 nucleons. How many neutrons has it? Answer with a number.

  2. 2.Put the shells in the order electrons fill them, starting from The K shell, nearest the nucleus.

    • The M shell
    • The K shell, nearest the nucleus
    • The N shell
    • The L shell

  3. 3.Oxygen's electronic configuration is 2, 6. What is its valency? Answer with a number.

  4. 4.An atom's outermost shell holds 8 electrons. What does the chapter say to expect of it?

    • a) It reacts readily, needing to gain eight more
    • b) It has a valency of eight
    • c) It is largely unreactive, its octet being complete
    • d) It reacts readily, needing to shed its eight

  5. 5.Match each element to its symbol.

    • Iron
    • Sodium
    • Potassium
    • Silver
    • Gold
    • K
    • Ag
    • Na
    • Au
    • Fe

  6. 6.Sort each subatomic particle by the charge it carries.

    Groups: Positive charge · Negative charge · No charge

    • Proton
    • Electron
    • Neutron

  7. 7.Using the rule that a shell numbered n holds at most 2n² electrons, what is the greatest number the M shell, where n is 3, can hold? Answer with a number.

  8. 8.Hydrogen occurs as three isotopes. Which one has two neutrons?

    • a) Each of the three has two
    • b) Protium
    • c) Tritium
    • d) Deuterium

Inside the atom · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 9 of 12

How atoms combine, and what a molecule weighs

Use the laws of conservation of mass and of constant proportions, tell a covalent bond from an ionic one, write a formula by crossing over valencies, and add up a molecular or formula unit mass.

Before you start

A sodium atom beside a chlorine atom, with each shell named.

1234
  1. 1. Sodium's inner shells, holding 2 then 8 electrons
  2. 2. Sodium's valence shell, holding its single electron
  3. 3. Chlorine's inner shells, holding 2 then 8 electrons
  4. 4. Chlorine's valence shell, holding 7 electrons

Sodium has one electron more than a full inner arrangement; chlorine is one short of eight. Hand the electron across and both are satisfied — that is an ionic bond in one move.

  1. 1.Which of these describes a molecule, as the chapter defines it?

    • a) The simplest whole-number ratio of ions in a crystal
    • b) A single atom of any element
    • c) An electrically neutral group of more than one atom that can exist on its own
    • d) A charged particle formed when an atom gains an electron

  2. 2.Sort each substance by the kind of bond holding it together.

    Groups: Held together by sharing electrons · Held together by transferring electrons

    • Magnesium oxide
    • Sodium chloride
    • Hydrogen molecule
    • Chlorine molecule

  3. 3.Sodium and chlorine combine in the mass ratio 23 to 35.5. If 46 g of sodium reacts completely, what mass of chlorine is needed, in g? Answer with a number.

  4. 4.Taking C as 12 u and H as 1 u, what is the molecular mass of methane, CH4, in u? Answer with a number.

  5. 5.Taking K as 39 u and Cl as 35.5 u, what is the formula unit mass of potassium chloride, KCl, in u? Answer with a number.

  6. 6.A sodium atom, with 11 protons and 11 electrons, loses its single valence electron. What is it now?

    • a) A cation, carrying one positive charge
    • b) A different element, since its proton count changed
    • c) Still a neutral atom, since electrons carry no charge
    • d) An anion, carrying one negative charge

  7. 7.Put the steps for writing a covalent compound's formula in order, starting from Write the symbols of the elements in the compound.

    • Cross the valencies over to the other symbol
    • Write the symbols of the elements in the compound
    • Write each element's valency below its symbol
    • Write them as subscripts, leaving out a subscript of one

  8. 8.A reaction is carried out in a sealed flask on a balance. What does the Law of Conservation of Mass predict about the reading?

    • a) It is the same before and after the reaction
    • b) It falls, because some matter is used up
    • c) It cannot be predicted without knowing the products
    • d) It rises, because new substances have been made

How atoms combine, and what a molecule weighs · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 10 of 12

Sound waves

Say why sound needs a medium, use v = λν and ν = 1/T, work out an echo distance, and place a frequency in the infrasonic, audible or ultrasonic band.

Before you start

Two sound waves, drawn one above the other.

12
  1. 1. The quieter wave — a small change in density, so less energy
  2. 2. The louder wave — a large change in density, so more energy

The two waves rise and fall the same number of times across the page, so they share a wavelength and a frequency. What differs is how far the density swings from its average — the amplitude.

  1. 1.Through which of these does sound travel fastest?

    • a) A steel rail
    • b) Air
    • c) It is the same speed in each
    • d) Sea water

  2. 2.In a large hall a sound seems to hang in the air after the speaker has stopped. What is that called, and what causes it?

    • a) Resonance, from the hall matching the speaker's frequency
    • b) An echo, from a single reflection arriving more than 0.1 s later
    • c) Reverberation, from repeated reflections arriving less than 0.05 s apart
    • d) Refraction, from the sound bending round the pillars

  3. 3.A point in a medium goes through 10 density oscillations in 4 s. What is the frequency of the wave, in Hz? Answer with a number.

  4. 4.A sound wave has a wavelength of 0.5 m and a frequency of 600 Hz. What is its speed, in m/s? Answer with a number.

  5. 5.A tuning fork is struck across the room. What reaches your ear?

    • a) Energy carried by the sound wave
    • b) A stream of compressed air from the fork
    • c) Small pieces of the fork itself
    • d) The air particles that were next to the fork

  6. 6.A wave has a time period of 0.02 s. What is its frequency, in Hz? Answer with a number.

  7. 7.Sort each description by the band of frequency it belongs to.

    Groups: Infrasonic · Audible to humans · Ultrasonic

    • Below 20 hertz
    • Between 20 hertz and 20 kilohertz
    • Above 20 kilohertz
    • Bursts a bat sends out to find its prey
    • Waves used to image internal organs without surgery
    • Waves used to detect earthquakes and volcanic eruptions

  8. 8.Sound travels at 340 m/s. What is the wavelength of a note of frequency 850 Hz, in m? Answer with a number.

Sound waves · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 11 of 12

Reproduction: how life continues

Tell asexual reproduction from sexual, name the parts of a flower and follow pollen through to a seed, and describe fertilisation and the reproductive cycle in animals and humans.

Before you start

The parts of a flower, each one named.

123456
  1. 1. The green flap at the base — a sepal
  2. 2. The broad flap sweeping out to the side — a petal
  3. 3. The small sac on the end of the slender stalk — the anther of a stamen
  4. 4. The flattened cap on top of the central column — the stigma
  5. 5. The thin central column — the style
  6. 6. The rounded swelling at the base of the column — the ovary

Sepals and petals are the two outer whorls. The stamen is the male part and the pistil — stigma, style and ovary together — is the female one.

  1. 1.What is the one-word name for the transfer of pollen grains from a stamen to a stigma?

  2. 2.Tap the part of this flower that produces the pollen grains.

    Write the number of the part.

    123456

  3. 3.A frog lays thousands of eggs in a pond while a bird lays a handful in a nest. What does the chapter say about the two strategies?

    • a) Both fertilise internally, and the difference lies in nest-building
    • b) The frog's fertilisation is external and survival is low; the bird's is internal and survival is better
    • c) Survival is the same in both; the frog simply lays more
    • d) The frog's fertilisation is internal and the bird's external

  4. 4.How many parts does a complete flower have? Answer with a number.

  5. 5.A gardener grows twenty plants from cuttings of one rose bush. How do the new plants compare with the parent?

    • a) They vary from it, because cuttings mix genetic material from two parents
    • b) They are genetically identical to it, because one parent and mitosis were involved
    • c) They vary, because meiosis takes place when a cutting roots
    • d) They are identical to each other but different from the parent

  6. 6.After fertilisation, what does each ovule inside the ovary become? Give the one word.

  7. 7.Sort each case by the kind of reproduction it is.

    Groups: Asexual reproduction · Sexual reproduction

    • A gardener rooting a sugarcane stem cutting
    • A male gamete from a pollen grain fusing with an egg cell
    • A potato sprouting new plants from its underground stem
    • A Bryophyllum leaf sprouting tiny plantlets
    • A frog releasing eggs into water for a male to fertilise

  8. 8.What is a fertilised egg called? Give the one word.

Reproduction: how life continues · Class 9 Science · www.arenapublications.com/learn

Class 9 Science · 12 of 12

Diversity and classification

Place an organism in one of the five kingdoms, run the hierarchy from kingdom down to species, and read and write a scientific name in the binomial system.

Before you start

The seven bands of the classification pyramid, each one named.

1234567
  1. 1. Kingdom, the broadest group of the seven
  2. 2. Phylum
  3. 3. Class
  4. 4. Order
  5. 5. Family
  6. 6. Genus
  7. 7. Species, the narrowest group of the seven

Each band sits inside the one above it, and the organisms in it share more features than the organisms in the band above. It works like an address, narrowing from country down to house.

  1. 1.Sort each organism into its kingdom.

    Groups: Monera · Protista · Fungi · Plantae

    • Spirogyra
    • Paramecium
    • Yeast
    • Cyanobacteria
    • Amoeba
    • Mushroom

  2. 2.A mango tree's scientific name has two words: Mangifera comes first. Which of the two words names the species? Write it.

  3. 3.Which of these is written according to the rules for a scientific name?

    • a) panthera Tigris, in italics
    • b) Panthera tigris, in italics
    • c) PANTHERA TIGRIS, in italics
    • d) Tigris panthera, in italics

  4. 4.Yeast is a single-celled organism, yet it is not placed in Protista. Why is it in Fungi?

    • a) It is multicellular under the microscope
    • b) It makes its own food by photosynthesis
    • c) It is a prokaryote
    • d) Its cell wall is made of chitin

  5. 5.In 1977 Carl Woese proposed a system with three groups above the kingdoms. What are they?

    • a) Bacteria, Archaea and Eukarya
    • b) Monera, Protista and Fungi
    • c) Chordata, Non-chordata and Protochordata
    • d) Plantae, Animalia and Fungi

  6. 6.A geologist digs down through undisturbed rock layers. What does the chapter say she will generally find as she goes deeper?

    • a) No fossils at any depth
    • b) Fossils of more complex organisms
    • c) Fossils of simpler organisms
    • d) The same organisms at each depth

  7. 7.Match each kingdom to what defines it.

    • Monera
    • Protista
    • Fungi
    • Plantae
    • Animalia
    • Multicellular eukaryotes with cellulose cell walls that make their own food
    • Eukaryotes with chitin cell walls that feed on dead matter
    • Single-celled eukaryotes
    • Prokaryotes, whose nucleus has no membrane around it
    • Multicellular eukaryotes without cell walls that feed on other organisms

  8. 8.Amoeba, Paramecium and Euglena are grouped together. What do they have in common that puts them in one kingdom?

    • a) They are multicellular and make their own food
    • b) They are prokaryotes with no true nucleus
    • c) They have cell walls made of chitin
    • d) They are single-celled eukaryotes living in water or moist places

Diversity and classification · Class 9 Science · www.arenapublications.com/learn

Answer keys — Class 9 Science

In the same order as the worksheets.

The cell and what is inside it

  1. 1. Genetic material in a bare nucleoid → Prokaryotic cell; A typical width of 1 to 10 micrometres → Prokaryotic cell; Membrane-bound organelles → Eukaryotic cell; Membrane-bound nucleus → Eukaryotic cell; A typical width of 10 to 100 micrometres → Eukaryotic cell
  2. 2. c) The rigid cell wall holds the outer shape while the membrane pulls inwards
  3. 3. c) Cellulose
  4. 4. c) New cells arise from cells that already exist
  5. 5. Hooke
  6. 6. d) It shrinks, because water leaves the cells for the more concentrated solution
  7. 7. Cell wall → In a plant cell but not an animal cell; Chloroplast → In a plant cell but not an animal cell; Large central vacuole → In a plant cell but not an animal cell; Cell membrane → In both a plant and an animal cell; Nucleus → In both a plant and an animal cell; Mitochondrion → In both a plant and an animal cell
  8. 8. c) Two daughter cells with the parent's chromosome number, genetically identical to it

Plant and animal tissues

  1. 1. stomata
  2. 2. b) Bone has a rigid matrix with calcium and phosphorus compounds; cartilage's matrix is soft and jelly-like
  3. 3. 1 — The branching fibres on the left
  4. 4. d) One bone to another bone
  5. 5. 1. The dendrites pick the message up from another neuron 2. The cell body, which holds the nucleus, takes it in 3. The axon carries it away as a long fibre 4. The axon terminals pass it on to the next cell
  6. 6. haemoglobin
  7. 7. 12
  8. 8. Skeletal muscle → Moves when we choose; Smooth muscle → Moves without our choosing; Cardiac muscle → Moves without our choosing

Distance, displacement, speed and velocity

  1. 1. a) Its direction keeps changing while its magnitude stays fixed
  2. 2. a) Uniform motion in a straight line
  3. 3. 3 — The stretch from O to B
  4. 4. 20
  5. 5. 0
  6. 6. Displacement → metre; Average velocity → metre per second; Average acceleration → metre per second squared
  7. 7. Total distance travelled → Number on its own; Average speed → Number on its own; Displacement → Number and a direction; Average velocity → Number and a direction; Average acceleration → Number and a direction
  8. 8. 40

Motion graphs and the kinematic equations

  1. 1. 1. Draw two perpendicular axes and mark where they cross as the origin 2. Decide which quantity goes along each axis 3. Choose a scale for each axis 4. Mark the values along each axis 5. Plot a point for each pair of readings 6. Join the plotted points to make the graph
  2. 2. 17
  3. 3. The slope of a position-time line → The average velocity; The slope of a velocity-time line → The acceleration; The area under a velocity-time line → The displacement
  4. 4. c) The velocity is changing, so the object is accelerating
  5. 5. 25
  6. 6. 25
  7. 7. 24
  8. 8. c) B has the greater magnitude of average velocity

Mixtures, concentration and separation

  1. 1. 1. Warm the water with the solid, stirring, until no more will dissolve 2. Filter the hot saturated solution to take out insoluble impurities 3. Cover the filtrate and leave it to cool slowly, undisturbed 4. Filter off the crystals and rinse them with cold water 5. Leave the crystals to dry on a watch glass
  2. 2. Particles smaller than 1 nanometre → Solution; Lets a laser beam through with no visible path → Solution; Particles between 1 and 1000 nanometres → Colloid; Scatters a light beam and yet stays evenly spread → Colloid; Particles larger than 1000 nanometres → Suspension; Particles you can see, which settle when left alone → Suspension
  3. 3. 2 — The lower layer
  4. 4. Distillation → Two miscible liquids with different boiling points; Separating funnel → Two immiscible liquids; Sublimation → A solid that sublimes mixed with one that does not; Paper chromatography → The coloured components of an ink or a dye; Centrifugation → Heavier particles from a lighter liquid
  5. 5. 4
  6. 6. 20
  7. 7. c) An alloy, and physical methods cannot separate its components
  8. 8. 12

Force and Newton's three laws

  1. 1. 2
  2. 2. a) The foot pushing the ground backwards and the ground pushing the foot forwards
  3. 3. 49
  4. 4. 3000
  5. 5. 8
  6. 6. Newton's first law → An object keeps its rest or its constant velocity until a net force acts; Newton's second law → The acceleration is the net force divided by the mass; Newton's third law → A force on one object is met by an equal and opposite force on the other
  7. 7. 2 — The string joining the two boxes
  8. 8. A tug of war in which both teams pull equally hard → Balanced forces; A book lying still on a table → Balanced forces; A rope moving towards the team that pulls harder → Unbalanced forces; A stalled car set moving by two people pushing → Unbalanced forces

Work, energy and power

  1. 1. 100
  2. 2. -30
  3. 3. 1. The elastic band is pulled back, and work is done on it 2. The stretched band holds that work as stored energy 3. The band is let go and pushes on the stone 4. The stone gains kinetic energy and shoots forward 5. The band returns to the shape it started in
  4. 4. 3
  5. 5. A boy pushing a wheelchair forward → Positive work done on the object; A goalkeeper stopping a moving ball → Negative work done on the object; Friction acting on a sliding stack of coins → Negative work done on the object; A girl slowly lowering a dumbbell → Negative work done on the object; A person pushing hard on a rigid wall → No work done on the object
  6. 6. b) None, because the wall did not move
  7. 7. b) It becomes four times as large
  8. 8. 30

Inside the atom

  1. 1. 30
  2. 2. 1. The K shell, nearest the nucleus 2. The L shell 3. The M shell 4. The N shell
  3. 3. 2
  4. 4. c) It is largely unreactive, its octet being complete
  5. 5. Iron → Fe; Sodium → Na; Potassium → K; Silver → Ag; Gold → Au
  6. 6. Proton → Positive charge; Electron → Negative charge; Neutron → No charge
  7. 7. 18
  8. 8. c) Tritium

How atoms combine, and what a molecule weighs

  1. 1. c) An electrically neutral group of more than one atom that can exist on its own
  2. 2. Hydrogen molecule → Held together by sharing electrons; Chlorine molecule → Held together by sharing electrons; Sodium chloride → Held together by transferring electrons; Magnesium oxide → Held together by transferring electrons
  3. 3. 71
  4. 4. 16
  5. 5. 74.5
  6. 6. a) A cation, carrying one positive charge
  7. 7. 1. Write the symbols of the elements in the compound 2. Write each element's valency below its symbol 3. Cross the valencies over to the other symbol 4. Write them as subscripts, leaving out a subscript of one
  8. 8. a) It is the same before and after the reaction

Sound waves

  1. 1. a) A steel rail
  2. 2. c) Reverberation, from repeated reflections arriving less than 0.05 s apart
  3. 3. 2.5
  4. 4. 300
  5. 5. a) Energy carried by the sound wave
  6. 6. 50
  7. 7. Below 20 hertz → Infrasonic; Waves used to detect earthquakes and volcanic eruptions → Infrasonic; Between 20 hertz and 20 kilohertz → Audible to humans; Above 20 kilohertz → Ultrasonic; Waves used to image internal organs without surgery → Ultrasonic; Bursts a bat sends out to find its prey → Ultrasonic
  8. 8. 0.4

Reproduction: how life continues

  1. 1. pollination
  2. 2. 3 — The small sac on the end of the slender stalk
  3. 3. b) The frog's fertilisation is external and survival is low; the bird's is internal and survival is better
  4. 4. 4
  5. 5. b) They are genetically identical to it, because one parent and mitosis were involved
  6. 6. seed
  7. 7. A potato sprouting new plants from its underground stem → Asexual reproduction; A Bryophyllum leaf sprouting tiny plantlets → Asexual reproduction; A gardener rooting a sugarcane stem cutting → Asexual reproduction; A male gamete from a pollen grain fusing with an egg cell → Sexual reproduction; A frog releasing eggs into water for a male to fertilise → Sexual reproduction
  8. 8. zygote

Diversity and classification

  1. 1. Cyanobacteria → Monera; Amoeba → Protista; Paramecium → Protista; Yeast → Fungi; Mushroom → Fungi; Spirogyra → Plantae
  2. 2. indica
  3. 3. b) Panthera tigris, in italics
  4. 4. d) Its cell wall is made of chitin
  5. 5. a) Bacteria, Archaea and Eukarya
  6. 6. c) Fossils of simpler organisms
  7. 7. Monera → Prokaryotes, whose nucleus has no membrane around it; Protista → Single-celled eukaryotes; Fungi → Eukaryotes with chitin cell walls that feed on dead matter; Plantae → Multicellular eukaryotes with cellulose cell walls that make their own food; Animalia → Multicellular eukaryotes without cell walls that feed on other organisms
  8. 8. d) They are single-celled eukaryotes living in water or moist places

Class 9 Science · www.arenapublications.com/learn