YEAR 7 END OF YEAR TEST

Question 1

describe the different types of wave and their features

Answer 1

transverse wave= its oscillation[vibration] is at 90 degrees to the direction of the wave and energy transfer.

longitudinal wave= its oscillation [vibration] is parallel to the direction of the wave.

Question 2

Describe what happens when water waves hit a barrier

Answer 2

Reflection involves a change in direction of waves when they bounce off a barrier. Refraction of waves involves a change in the direction of waves as they pass from one medium to another. Refraction, or the bending of the path of the waves, is accompanied by a change in speed and wavelength of the waves.

Question 3

Describe what happens when waves superpose

Answer 3

They add up or cancel out . If they add up you get more. If they cancel out you get less.

Question 4

Describe how sound is produced and travels.

Answer 4

Sounds are made when objects vibrate it makes the molescules vibrate producing a sound wave.
Sound travels in waves.

Question 5

Explain why the speed of sound is different in different materials

Answer 5

Sound travels faster through liquids and solids than it does through air and other gases. This is because the particles of gases are further apart than liquids and finally solids. Sound waves move more slowly when particles are further apart.

Question 6

Contrast the speed of sound and the speed of light

Answer 6

Sound travels at 340 metres per second.

Light travels at 300,000,000 metres per second.

Question 7

Describe the link between loudness and amplitude.

Answer 7

The larger the amplitude of the waves, the louder the sound.

Question 8

Describe the link between frequency and pitch

Answer 8

The sensation of a frequency is commonly referred to as the pitch of a sound. A high pitch sound corresponds to a high frequency sound wave and a low pitch sound corresponds to a low frequency sound wave.

Question 9

state the range of human hearing and describe how it differs from the range of hearing in animals.

Answer 9

human hearing is 20 to 20,000 Hz
Not only can some animals hear low frequency sounds three times more than humans, they can also hear sounds close to four times farther than human hearing range.

Question 10

describe how the ear works

Answer 10

The outer ear consists of the pinna (also called the auricle), ear canal and eardrum.
The middle ear is a small, air-filled space containing three tiny bones called the malleus, incus and stapes but collectively called the ossicles. The malleus connects to the eardrum linking it to the outer ear and the stapes (smallest bone in the body) connects to the inner ear.
The inner ear has both hearing and balance organs. The hearing part of the inner ear and is called the cochlea which comes from the Greek word for ‘snail’ because of its distinctive coiled shape. The cochlea, which contains many thousands of sensory cells (called ‘hair cells’), is connected to the central hearing system by the hearing or auditory nerve. The cochlea is filled with special fluids which are important to the process of hearing.

Question 11

describe how your hearing can be damaged

Answer 11

Things like a cotton swab, fingernail, or pencil can scratch the ear canal or cause a tear or hole in the eardrum (called a ruptured eardrum). Direct blows to the ear or head. Falls, car accidents, sports injuries, or fights may tear the eardrum, dislocate the ossicles (tiny ear bones), or damage the inner ear.also very loud sounds can damage your ear .

Question 12

Describe how a microphone detects sound

Answer 12

The most common mechanical detector of sound is the microphone. It has a membrane that is made to vibrate by the sound. That vibration is changed to electrical signals, which are then sent to a processor or electronic circuitry for amplification or such.

Question 13

Describe what ultrasound is

Answer 13

Ultrasound, also called sonography, uses sound waves to develop ultrasound images of what’s going on inside the body.

Question 14

Describe some uses of ultrasound

Answer 14

• animals use ultrasound to communicate and hunt.
• it can be used to make an image of a fetus or to break down kidney stones.
• fisherman can use ultrasound to find the depth of the ocean.

Question 15

Describe how materials are made up of particles

Answer 15

Matter on Earth is in the form of solid, liquid, or gas. Solids, liquids, and gases are made of tiny particles called atoms and molecules. In a solid, the particles are very attracted to each other.

Question 16

Use the particle model to explain why different materials have different
properties

Answer 16

The Particle Theory of Matter helps us think about how matter behaves. It also helps us explain why different matter has different properties. It has several key ideas: All matter is made of tiny particles. These particles are either individual atoms or groups of atoms called molecules

Question 17

Describe the properties of a substance in its three states

Answer 17

Almost all substances can be classified into three states of matter – solids, liquids and gases. Each state has different properties. Heating and cooling a substance can cause it to change state. The kinetic particle theory explains the properties of the different states of matter.

Question 18

Use ideas about particles to explain the properties of a substance in its three
states

Answer 18

The particle model Kinetic theory models the arrangement and movement of particles in solids, liquids and gases. It explains properties of substances in these different states, and what happens during changes of state.

Question 19

Use the particle model to explain changes of state

Answer 19

The particle model describes the arrangement of particles in solids, liquids and gases. It can be used to predict changes when matter is heated. In everyday life, there are three states of matter - solids, liquids and gases. The differences between the three states are due to the arrangement and spacing of the particles and their motion.

Question 20

Interpret data about melting points

Answer 20

melting point is the temperature at which a solid changes into a liquid.

Question 21

Use the particle model to explain boiling

Answer 21

The particle model is used to predict the possibility of the gas state and ‘gases’ are understood to be substances which happen to have boiling points below room temperature. A substance can be in any of the three states and there is nothing special about substances room temperature states.

Question 22

Interpret data about changes of state

Answer 22

Key points
Solids, liquids and gases change state when they are heated or cooled.
Processes such as evaporation and boiling change the state of substances.
A particle model can be used to show how solids, liquids and gases change state.

Question 23

Describe changes of state involving gases

Answer 23

A substance in the gas state condenses when it is cooled, which changes it to the liquid state. Continued cooling causes it to freeze, which changes it to the solid state. During evaporation, particles with enough energy can escape the liquid as a gas.

Question 24

Use the particle model to explain evaporation, condensation, and
sublimation

Answer 24

EVAPORATION:
Evaporation may also involve liquids other than water e.g. perfume, petrol, air fresheners. The particle model can be used to explain how it is possible to detect smells some distance away from the source. If a liquid is heated the particles are given more energy and move faster and faster expanding the liquid.
CONDENSATION:
Energy must be transferred from a substance to the environment for condensing and freezing to happen. During these changes of state the particles lose energy as forces of attraction form between them. Limitations of the particle model - Higher tier The particle model does not take into account: the size and shape of particles
SUBLIMATION:
Sublimation is a technique used by chemists to purify compounds. A solid is typically placed in a sublimation apparatus and heated under vacuum. Under this reduced pressure, the solid volatilizes and condenses as a purified compound on a cooled surface (cold finger), leaving a non-volatile residue of impurities behind.

Question 25

Use the particle model to explain diffusion

Answer 25

Diffusion is driven by differences in concentration. When chemical substances such as perfume are let loose in a room, their particles mix with the particles of air. The particles of smelly gas are free to move quickly in all directions.

Question 26

Describe evidence for diffusion

Answer 26

Evidence for particles - diffusion Diffusion in gases When chemicals, like the smell of perfume or burning toast, are let loose in a room, the particles mix with the air particles. The particles of smelly gas are free to move quickly in all directions.

Question 27

Use the particle model to explain gas pressure

Answer 27

The particle model describes the arrangement of particles in solids, liquids and gases. It can be used to predict changes when matter is heated. If the volume of a container with a gas inside stays the same, the pressure of a gas increases as its temperature increases.

Question 28

Describe the factors that affect gas pressure

Answer 28

Gas pressure is caused when gas particles hit the walls of their container. The more often the particles hit the walls, and the faster they are moving when they do this, the higher the pressure. This is why the pressure in a tyre or balloon goes up when more air is pumped in.

Question 29

State what an element is

Answer 29

An element is a substance whose atoms all have the same number of protons: another way of saying this is that all of a particular element’s atoms have the same atomic number. Elements are chemically the simplest substances and hence cannot be broken down using chemical reactions.

Question 30

Recall the chemical symbols of six elements

Answer 30

B = boron
C = carbon
N = nitrogen
O = oxygen
Cl = chlorine
Pb = lead

Question 31

State what atoms are

Answer 31

the smallest part of an element that can exist is called an atom.

Question 32

Compare the properties of one atom of an element to the properties of many atoms

Answer 32

all the atoms of an element are the same. the atoms of one element are different to the atoms of al other elements.

Question 33

State what a compound is

Answer 33

when you chemically join two elements together you form a compound.
a compound is a substance made up of atoms of two or more elements.

Question 34

Explain why a compound has different properties to the elements in it

Answer 34

the elements in a compound have their own properties but when they chemically join together the properties change. a compound has different properties to the elements it is made from .e.g. hydrogen and oxygen have different properties to water.

Question 35

Write the chemical names for some simple compounds

Answer 35

water H

Question 36

Write the chemical names for some simple compounds

Answer 36

Common Name- Chemical Name- Chemical Formula
Baking Soda- Sodium hydrogen carbonate or Sodium bicarbonate- NaHCO 3
Baryta- Barium hydroxide- Ba (OH) 2
Bleach (laundry)- Sodium hypochlorite- NaOCl
Bleaching powder- Calcium hypochlorite- Ca (ClO) 2

Question 37

Write and interpret chemical formulae

Answer 37

compound names and formulae tell us about the elements they are made from.
.e.g. iron sulfide = iron and sulphur

Question 38

Describe what a cell is

Answer 38

the building blocks of life

Question 39

Explain how to use a microscope to observe a cell

Answer 39

Move the stage (the flat ledge the slide sits on) down to its lowest position.

Place the glass slide onto the stage. Be careful pushing it under the clips that the cover slide doesn’t move or crack.

Select the lowest power objective lens.

Turn the coarse focus knob slowly until you are able to see the cells.

Turn the fine focus knob slowly until the cells are in focus and you can see them clearly.

Repeat steps 1-5 using the higher power magnification to see the cells in more detail.

Question 40

Describe the functions of the components of a cell

Answer 40

Here are some of the main components many cells have: Membrane - This is the outer boundary of the cell. Sort of like the skin. It allows some substances in and keeps others out. Mitochondria - This is where the cell gets its energy. In the human body, food we have digested reacts with oxygen in the mitochondria to make energy for the cell

Question 41

Describe the similarities and differences between plant and

animal cells

Answer 41

the similarities of plant and animal cells are that they both contain nucleus and a difference is the plant cells are packed full of chloroplasts and animal cells don’t contain chloroplasts. plant cells have a regular structure and animal cells have a irregular structure. the plant cells have photosynthesis and the animal cells don’t.

Question 42

Describe examples of specialised animal cells

Answer 42

red blood cells = carry oxygen around the body

Question 43

Describe examples of specialised plant cells

Answer 43

leaf cells = are packed full of chloroplasts to carry out photosythesis

Question 44

Name some substances that move into and out of cells

Answer 44

diffusion

Question 45

Describe the process of diffusion

Answer 45

diffusion= substances move from an area where they are in a high concentration to an area where they are in a low concentration.

Question 46

Describe what a unicellular organism is

Answer 46

A unicellular organism is a living thing that is just one cell.

Question 47

Describe the structure of an amoeba

Answer 47

Amoebas are simple in form consisting of cytoplasm surrounded by a cell membrane. The outer portion of the cytoplasm (ectoplasm) is clear and gel-like, while the inner portion of the cytoplasm (endoplasm) is granular and contains organelles, such as a nuclei, mitochondria, and vacuoles.

Question 48

Describe the structure of a euglena

Answer 48

Euglena lacks a cell wall. Instead, it has a pellicle made up of a protein layer supported by a substructure of microtubules, arranged in strips spiraling around the cell. The action of these pellicle strips sliding over one another, known as metaboly, gives Euglena its exceptional flexibility and contractility.

Question 49

Define and state examples of tissues, organs, and organ systems

Answer 49

tissues = group of similar cells working together
organs = group of tissues working together.
organ system = group of organs working together

Question 50

Explain the hierarchy of organisation in a multicellular organism

Answer 50

The five levels of multicellular organization are cells, tissues, organs, and organ systems, and organisms. Tissues are any of the distinct types of material of which animals or plants are made, consisting of specialized cells and their products.

Question 51

Describe the structure of the gas exchange system

Answer 51

Trachea=This is also called the windpipe. This tube runs from the mouth, down the throat towards the lungs. It is lined with rings of cartilage which keep it open at all times.

Bronchus=The trachea splits into a left and right bronchus (plural: bronchi), each leads to a lung.

Bronchiole=Each bronchus splits again and again into thousands of smaller tubes called bronchioles which take the air deeper into the lungs.

Alveoli=At the ends of bronchioles are tiny air sacs called alveoli. Here oxygen moves into the blood and carbon dioxide moves out.

Intercostal muscles=These muscles run between the ribs and form the chest wall. They contract and relax with the diaphragm when a person breathes.

Diaphragm=The diaphragm is a dome-shaped, flat sheet of muscle under the lungs. It contracts and relaxes with the intercostal muscles during breathing

Question 52

Describe how parts of the gas exchange system are adapted to their function

Answer 52

Some adaptations are related to the alveoli, exercise, surface area, and ventilation. The alveoli are the location of gas exchange in the lungs. They have several adaptations that make the diffusion of oxygen and carbon dioxide between the lungs and the blood more efficient. For example, each alveoli is thin-walled and is wrapped in capillaries.

Question 53

Describe the processes of inhaling and exhaling

Answer 53

INHALING:
when we breathe in, the muscles move the ribs up and outwards. the diaphragm moves down. the size of the chest gets bigger. this causes air to rush into your lungs.

EXHALING:
when we breathe out , the muscles move the ribs down and inwards. the diaphragm moves up. the size of the chest gets smaller. this causes air to rush out of your lungs.

Question 54

Describe how a bell jar can be used to model what happens during breathing

Answer 54

The bell jar model illustrates these key features of the breathing process: As the rubber sheet (diaphragm) moves down, the volume inside glass jar increases (the thorax/chest cavity) This causes the pressure inside the glass jar to decrease below atmospheric pressure This caused air to enter the balloons (lungs)

Question 55

Explain how to measure lung volume

Answer 55

Turn the bottle upside down. Place the top of the bottle under the water in the sink before removing your hand. Push one end of the plastic tube into the bottle. Take a big breath in. Breathe out as much air as you can through the tube. Measure the volume of air your lungs had in them.

Question 56

describe the functions of the skeletal system

Answer 56

support the body
protect vital organs
help the body move
make blood cells

Question 57

Describe the structure of the skeleton

Answer 57

29 bones in the head – (8 cranial and 14 facial bones) and then also 7 associated bones (6 auditory ossicles and the Hyoid Bone)
25 bones of the thorax – (the sternum and 24 ribs)
26 bones in the vertebral column (24 vertebrae, the sacrum, and the coccyx)

Question 58

Describe the role of joints in movement

Answer 58

Joints have two main purposes: They give support, and they allow movement where it is needed. All animals that have segments have joints. The joints of arthropods —insects, spiders, crabs, and similar creatures—connect the external skeleton, which is made of a shell-like substance called chitin.

Question 59

Explain how to measure the force exerted by different muscles

Answer 59

the formula can be rewritten: power = force × velocity. Sports scientists use this formula to measure the power profiles of particular sets of muscles by measuring both the force of the muscles and the speed with which they are contracting or lengthening.

Question 60

Describe the function of major muscle groups

Answer 60

Muscles provide the tug on the bones needed to bend, straighten, and support joints. Muscles can pull on bones, but they can’t push them back to their original position, so the muscles work in pairs of flexors and extensors. The extensor muscle relaxes and stretches as the flexor muscle contracts to bend the joint.

Question 61

Explain how antagonistic muscles cause movement

Answer 61

Agonist muscles shorten with contraction to produce a movement.
Following contraction, the antagonist muscle paired to the agonist muscle returns the limb to the previous position.
Synergist muscles act around a movable joint to produce motion similar to or in concert with agonist muscles, allowing for a range of possible movements.

Question 62

State the difference between adolescence and puberty

Answer 62

the period of time when a person develops from a child to an adult is known as adolescence. the physical changes that take place are known as puberty.

Question 63

describe the main changes that take place during puberty

Answer 63

Girls develop breasts and start their periods. Boys develop a deeper voice and facial hair will start to appear.

Question 64

Describe the main structures in the male and female reproductive
systems

Answer 64

Male structures :
-Sperm ducts - muscular ducts about 30cm long.

• Glands- small structures near the uretha.
• Urethra- tube in penis.
• Penis- sex organ, cylindrical in shape.
• Testis- oval organs in the scrotum.
• Scrotum- bag of skin containing the testis.

Question 65

Describe the function of the main structures in the male

reproductive systems

Answer 65

Male function:

• Sperm duct-these are tubes that carry sperm from the testis to the penis.
• glands-they produce nutrients that help to keep the sperm alive. The mixture of sperm and fluid - semen.
• uretha- a tube that carries urine from the bladder out of the body.
• penis- inserts sperm into female.
• testis- produce sperm and male sex hormones.
• scrotum- keeps the temperature of the testis slightly lower than the rest of the body.

Question 66

Describe the function of the main structures in the female

reproductive systems

Answer 66

Female function:

• Oviduct- carries the egg to the uterus.
• ovaries- store and egg release,
• uterus- where a fetus /baby develops until birth.
• cervix- keeps the fetus/ baby in place.
• vagina- receives the sperm during sexual intercourse.
• uretha- carries urine out of the body.

Question 67

Describe the structure and function of gametes

Answer 67

Structure:

It is microscopic, consists of a head, a neck, a middle piece, and a tail.

Function:

Reproductive cells

Question 68

Describe the processes of fertilisation

Answer 68

1-Fertilisation is the joining together of a sperm and an egg.

2-The sperms swim through the cervix , up the uterus and into the egg tube to find the egg.

3-This is a very long way for the sperms to swim and most of them will not reach the egg.

4-To overcome these loses millions of sperms are released into the vagina at once.

5-A number of sperms may reach the egg but only one is able to enter it .

6- This is because the egg makes a skin around itself tii ok stop other sperms from entering.

7- The egg can live for about a day and a sperm can live for up to 3 days.

8- so there are only about 3 days in a month when it is possible for the egg to be fertilised.

Question 69

Describe what happens during gestation

Answer 69

A fetus develops in the uterus. This is known as gestation. The fluid sac protects the fetus from bumps. The fetus is attached to the placenta by the umbilical cord. Substances transfer between the mother and baby through their blood in the placenta. After 40 weeks the baby is ready to be born.

Question 70

Describe what happens during birth

Answer 70

During childbirth, the muscles at the top of your uterus press down on the baby’s bottom. Your baby’s head then presses on your cervix which, along with the release of the hormone oxytocin which brings on contractions.

Question 71

State what the menstrual cycle is

Answer 71

The female reproductive system works in a cycle called the menstrual . An egg is released each month . If the egg is not fertilised the. The lining of the uterus breaks down and leaves the body through the vagina. This is called a period.

Question 72

Describe the main stages in the menstrual cycle

Answer 72

day 1- blood from the uterus lining leaves the body through the vagina.

day 5 - bleeding stops. the lining of the uterus begins to re-grow. the ling is spongy and filled with blood. this will provide a deep layer for imlantation if an egg cell is fertilised.

day 14 - an egg cell is released from one of the ovaries.this is called ovulation. the egg cell travels through the oviduct towards the uterus.

Question 73

Identify the main structures of a flower

Answer 73

Sepal- protects the flower bud.

Petal- attracts insects.

Filament- holds the anther up.

Anther- makes the pollen.

Stigma- sticky platform for pollen to attach to.

Style- holds the stigma above the ovary.

Ovary- contains the egg cell.

Question 74

Describe the process of pollination

Answer 74

1- a bee visits a flower to feed on nectar. The bee wriggles deep into the flower past the anthers.

2- as the bee passes the anthers, pollen grains stick to the hair on the bees body .

3- the bee flies to another flower, carrying pollen from the first flower with it .

4- the bee feeds on the nectar in the second flower.

5- pollen grains from the bee get stuck in the sticky stigma .

6- a pollen grain develops a pollen tube that grows down the style to the ovule.

7- the pollen grain nucleus joins with the egg nucleus.

8- the fertilised egg develops into a seed.

Question 75

describe the differences between wind-pollinated and insectpollinated plants

Answer 75

Unlike insect pollinated plants, wind pollinated plants are not scented, because there is no need to attract insects with scent. Unlike insect pollinated plants, wind pollinated plants offer no nectar (nectar is an important food reward for bees and other pollinating insects)

Question 76

Describe the process of fertilisation in plants

Answer 76

In plants, fertilization is a process of sexual reproduction, which occurs after pollination and germination. Fertilization can be defined as the fusion of the male gametes (pollen) with the female gametes (ovum) to form a diploid zygote. It is a physicochemical process which occurs after the pollination of the carpel

Question 77

Describe how seeds and fruits are formed

Answer 77

Fruits are a way which many plants spread their seeds. Fruits are formed after the flower is fertilized with pollen. The ovules in the pistil will become seeds and the flower will transform into a fruit. The seed is the embryo of a plant.

Question 78

State the ways seeds can be dispersed

Answer 78

There are five main modes of seed dispersal: gravity, wind, ballistic, water, and by animals

Question 79

Describe how a seed is adapted to its method of dispersal

Answer 79

Some seeds are transported by the wind and are shaped to float, glide or spin through the air. Plants growing near a river may use the flowing water to transport their seeds. Some seed pods are designed to explode and throw the seeds a good distance from the parent plant.

Question 80

Explain what forces do

Answer 80

A force is a push or pull that causes a change in speed, direction or shape.

Question 81

Describe what is meant by an interaction pair

Answer 81

When two objects interact - usually by pressing upon or pulling upon each other - a pair of forces results with one force being exerted on each of the objects in the pair of objects. This interaction force pair can easily be identified and described by words.

Question 82

Describe how forces deform objects

Answer 82

Objects under the actions of external forces undergo deformation. This may be squashing, twisting, ripping, or pulling apart the object. In Physics, two terms describe the force on objects undergoing deformation: stress and strain. The quantity that describes the magnitude of forces that cause deformation is known as stress.

Question 83

Explain how solid surfaces provide a support force

Answer 83

When you step on a solid (like the floor) the bonds between the atoms are compressed. When you stand on the floor, your weight pushes the particles together. The bonds between the atoms are compressed and they begin to push back. Them pushing back, supports you and stops your from falling through. This support force is called the reaction force.

Question 84

Use Hooke’s Law

Answer 84

a law stating that the strain in a solid is proportional to the applied stress within the elastic limit of that solid.

its the elastic limit

Question 85

Describe the effect of drag forces and friction

Answer 85

Friction partly causes drag. Air resistance and water resistance are Drag forces. When an object moves through a fluid medium, it bumps into particles. The more particles it bumps into, the slower it becomes and the more drag it creates. We use drag force to slow objects down. Sky divers and race cars use parachutes to slow themselves down.

Question 86

Explain why drag forces and friction arise

Answer 86

Friction partly causes drag. Air resistance and water resistance are Drag forces. When an object moves through a fluid medium, it bumps into particles. The more particles it bumps into, the slower it becomes and the more drag it creates.

Question 87

Describe the effects of a field

Answer 87

The effect of the field depends on the charge of the radiation. Alpha particles are positively charged and are therefore attracted to the negative plate in an electric field. Beta particles are negatively charged and are therefore attracted to the positive plate in an electric field.

Question 88

Describe the effect of gravitational forces on Earth and in

space

Answer 88

Gravity holds the atmosphere in place around the Earth. Gravity keeps people on the Earth’s surface. Gravity keeps the International Space Station in orbit around the Earth.

Question 89

Describe the difference between balanced and unbalanced

forces

Answer 89

In balanced forces, the magnitude of the two forces is equal, whereas, in the case of unbalanced forces, the magnitude of the two forces are unequal. In balanced forces, the two individual forces act in opposite direction. Conversely, in unbalanced forces, the individual forces either act in same or opposite direction.

Question 90

Describe situations that are in equilibrium

Answer 90

If an object is at equilibrium, then the forces are balanced. Balanced is the key word that is used to describe equilibrium situations. Thus, the net force is zero and the acceleration is 0 m/s/s. Objects at equilibrium must have an acceleration of 0 m/s/s.

Question 91

Explain why the speed or direction of motion of objects can

change

Answer 91

When an object moves in a circle at a constant speed, its direction constantly changes. A change in direction causes a change in velocity. This is because velocity is a vector quantity – it has an associated direction as well as a magnitude.