Science - Term 2 + 2nd half Flashcards

Question

Wave frequency

Answer 1

The number of waves passing a point each second. Measured in hertz.

Answer 2

The length of time it takes one wave to pass a given point.

Answer 3

The distance from a point on one wave to a point in the same position on the next wave, measured in metres.

Answer 4

The maximum distance of a point on the wave away from its rest position, measured in metres. The greater the amplitude of a sound wave, the louder the sound.

Answer 5

The speed of the wave in the direction it is travelling. Waves travel at different speeds in different materials.

Answer 6

The amplitude of a wave is from the middle of the top or bottom of two waves not the distance between top of one wave and the bottom of another.

Answer 7

Speed(m/s) = Distance (m) / time (s)

Answer 8

wave speed (m/s) = frequency (Hz) x wavelength (m)

Answer 9

Sound waves enter the ear canal.

Answer 10

1. The ear drum is a thin membrane. sound waves make it vibrate.

Answer 11

2. Vibrations are passed on to tiny bones which amplify the vibrations (make them bigger).

Answer 12

Vibrations are passed on to the liquid inside the cochlea.

Answer 13

Tiny hairs inside the cochlea detect these vibrations and create electrical signals called impulses.

Answer 14

Impulses travel along neurons in the auditory nerve to reach the brain.

Answer 15

The cochlea is a coiled tube containing liquid. It can detect the different frequencies of sound reaching the ear.

Answer 16

Sound made by waves with higher frequencies than this.

Answer 17

Sounds with a frequency less than 20Hz are too low for humans to hear.

Answer 18

A way of modelling what happens when light is reflected or refracted.

Answer 19

When waves are reflected, the angle of reflection is equal to the angle of incidence.

Answer 20

This is the line drawn at a right angle to the barrier or mirror.

Answer 21

A ray of light that strikes a surface

Answer 22

Light ray that bounce off a surface.

Answer 23

The bending of light (it also happens with sound, water and other waves) as it passes from one transparent substance into another.

Answer 24

The angle between a refracted ray and the normal drawn at the point of incidence to the interface at which refraction occurs.

Answer 25

The complete reflection of a ray of light within a medium such as water or glass from the surrounding surfaces back into the medium.

Answer 26

The angle of incidence when the angle of refraction is 90o, and the ray changes from just refracting to total internal reflection.

Answer 27

The reflection of light from a surface such that an incident ray is reflected at many angles, rather than at just one angle.

Answer 28

The segment of the electromagnetic spectrum that the human eye can view.

Answer 29

Electromagnetic radiation of all the frequencies in the visible range of the spectrum, appearing white to the eye.

Answer 30

A form of radiation that travel though the universe.

Answer 31

We cannot see ultraviolet (UV) light but it can have hazardous effects on the human body. Ultraviolet light in sunlight can cause the skin to tan or burn. Fluorescent substances are used in energy-efficient lamps - they absorb ultraviolet light produced inside the lamp, and re-emit the energy as visible light. Similar substances are used on bank notes to detect forgeries. The hazardous properties of UV mean it will kill bacteria and can be used for disinfecting water.

Answer 32

Infrared radiation (IR), sometimes referred to simply as infrared, is a region of the electromagnetic radiation spectrum where wavelengths range from about 700 nanometres (nm) to 1 millimetre (mm). Infrared waves are longer than visible light waves but shorter than radio waves.

Answer 33

Responsible for muscle coordination and movement. * It is found at the back of the brain * Responsible for... ○ Muscle co-ordination Balance

Answer 34

Outer layer of neural tissue. Responsible for consciousness, memory, intelligence and language.

Answer 35

Master gland, responsible for regulating many body functions, controlling the activity of other glands.

Answer 36

Controls unconscious activities, like breathing and heart rate.

Answer 37

Carries information between the brain and the rest of the body.

Answer 38

Controls your heart and breathing rate

Answer 39

* the largest part of the brain * It is split into left and right cerebral hemispheres, they control the muscles in the opposite halves of the body E.g. The left cerebral hemisphere control muscles on the right half of your body * Different parts of the cerebrum are responsible for different things including ○ Movement ○ Language ○ Vision ○ Memory Intelligence

Answer 40

* Part of the central nervous system Made up of billions of interconnected neurones with the purpose of sending electrical impulses down the relay neurones

Answer 41

* Use x-rays to produce images of the brain, so ○ You can look at the structure but not the seen their functions * CTs can show damaged or diseased parts of the brain so if the patient has lost a function you know it is related to that part E.g. If the area at the back of the brain is damaged and the patient cannot see then that part of the brain is related to vision

Answer 42

* For PET scanners, you are injected with a radioactive chemical called tracer. The tracer moves around the body and collects in different areas, the more active cells take up more tracer than less active cells. When the person is inside the tracer we can see where the tracer builds up. ○ So you can see which parts of the brain are currently active * PET scanners investigate both structure and function at the same time * PET scan can show areas of the brain that are active or inactive, so we can study these changes E.g. Alzheimer's disease is a brain disorder. The mains symptom is memory loss and if we look at where the patient has less activity in certain areas compared to a normal brain. We can discover where in the brain the problem lies

Answer 43

* It is hard to repair damaged parts of the nervous system because neurones there do not readily repair themselves and scientists have not discovered ways to repair them * It is hard to access parts of the brain E.g. We cannot surgically remove tumours in certain parts of the brain The treatment may cause further damage that may or may not be permanent.

Answer 44

The neurons and the brain

Answer 45

The nervous system sends messages through out the body as electrical signals.

Answer 46

A travelling impulse and happens in the neurones.

Answer 47

1. Stimulus 2. Impulse starts at receptor. 3. Impulse passed along sensory neurone. 4. Impulse passed along motor neurone. 5. Effector(muscle) receives impulse to react. 6. Response

Answer 48

A system that allows you to recognise to a stimuli in the surrounding and co-ordinate a response or behavioural change.

Answer 49

A changes in the environment and to survive the change organisms must respond to these stimuli.

Answer 50

One cell in an organism

Answer 51

Several cells in the organism

Answer 52

Sensory receptors are groups of cells that detect stimuli and initiate a response.

Answer 53

Eyelids->detect light Skin->detect pressure, touch, tissue damage, temperature

Answer 54

The transparent outer layer at the front of the eye. It refracts light into the eye.

Answer 55

It retracts light, focusing it onto the retina.

Answer 56

The hole in the centre of the eye, through which light enters.

Answer 57

It contains muscles that allow it to control the diameter of the pupil and therefor how much light enters the eye.

Answer 58

The layer at the back of the eye that contains 2 types of receptor cells (cones and rods)

Answer 59

Sensitive to light intensity.

Answer 60

Sensitive to colour.

Answer 61

It control the shape of the lenses.

Answer 62

○ This occurs when... § the eyeball is to short § The lens is the wrong shape § The lens does not refract the light enough To correct this you can wear glasses or contact lenses with a convex lens (lenses that curve outwards)

Answer 63

○ This occurs when... § the eyeball is to long § The lens is the wrong shape § The lens refract the light too much ○ To correct this you can wear glasses or contact lenses with a concave lens (lenses that curve inwards)

Answer 64

Cannot focus on nearby objects.

Answer 65

Cannot focus on distant objects.

Answer 66

When you cannot tell the difference between two colours.

Answer 67

A blurry patch on the eye that stops light from entering the eye.

Answer 68

○ People with cataract have § Blurred vision § Colours are less vivid Have difficulty seeing bright lights

Answer 69

- There only needs to be one parent so they can reproduce in any favourable condition without having to wait for a mate. - The reproductive cycle is faster than sexual reproduction so you can produce more offspring quickly and colonise a new area

Answer 70

- There is no variation between offspring when created through asexual reproduction so if the environment changes and the conditions become unfavourable the entire population will not be able to cope. - Less chance of adapting to new conditions

Answer 71

- There is variation between offspring when created through sexual reproduction Short term: population is less likely to get wiped out by a single event Long term : Population is likely to adapt to changing conditions. This allows for evolution to take place. * Most favourable traits are most likely to survive Species change over time

Answer 72

- Time * The reproductive cycle is slower than asexual reproduction so you can produce less offspring. There needs to be two parent so they are dependent on a mate. - Energy * To impress mate

Answer 73

- 2 parent (M+F)-meiosis - Gametes - specialised cell * Sperm * Egg - Genetically different offspring. Less likely to all have the same genetic problems

Answer 74

Half the number of chromosomes

Answer 75

- 1 parent - mitosis - No gametes - Clone - look the same They both have same generic diseases

Answer 76

Full set of chromosomes

Answer 77

Look the same

Answer 78

Both sexual organs

Answer 79

* Most cell structures have a nucleus that contains genetic material that is stored in chromosomes * Body cells normally have two copies of each chromosome (diploid) One from mother's gamete and one from father's gamete

Answer 80

A process where body cells in multicellular organisms divide to produce new cells.

Answer 81

When a cell reproduces itself splitting into two to form two genetically identical offspring (specifically focusing on the division of the nucleus)

Answer 82

- The division of the cytoplasm that takes place at the same time as mitosis. - When before telophase ends, the cytoplasm and cell membrane divide to form two separate cells daughter cells.

Answer 83

1. In a cell that is not dividing, the DNA is all spread out in long strings 2. Before it divides, the cell has to grow and increase the amount of subcellular structures 3. It then duplicates its DNA so there are 2 copies of each chromosome for each new cell. The replicated DNA stay attached to the original to form and X-shape. An arm(chromatid) is an exact copy of the other.

Answer 84

1. Prophase 2. Metaphase 3. Anaphase 4. Telophase

Answer 85

The chromosomes condense getting shorter and fatter and the nuclear membrane breaks down so the chromosomes lie free in the cytoplasm.

Answer 86

The chromosomes line up along the centre of the cell and the spindle fibres attach to them.

Answer 87

The spindle fibres pull the chromosome apart and the chromatids are pulled to opposite ends of the cell.

Answer 88

Membranes form around each set of chromosomes to form a nucleus.

Answer 89

* Growth * Replacing damaged cells * Asexual reproduction

Answer 90

Number of cells = 2^n n=number of cell divisions

Answer 91

Cells replicating by mitosis all the time.

Answer 92

A bunch of cells that grow abnormally and then stop.

Answer 93

A bunch of cells that keep replicating and invading other areas.

Answer 94

A bunch of cells that start appearing somewhere else.

Answer 95

* UV lights * Carcinogens * Genetics

Answer 96

When genetic information from a male and female gametes are combined to produce an offspring which is genetically different to either parent.

Answer 97

- The fusion of the male and female gametes. - When a male gamete fuses with a female gamete (produce a zygote for humans).

Answer 98

A haploid that is produced by meiosis. E.g. Egg (Female gamete) and sperm (male gamete) for animals.

Answer 99

Gametes that contain half the number of chromosomes in a normal cell(so one copy of each chromosome)

Answer 100

Gametes that have two copies of each chromosome.

Answer 101

A fertilized egg that ends up with the full number of chromosomes. * The zygote turns into an embryo through mitosis.

Answer 102

The entire set of DNA instructions found in a cell.

Answer 103

The instructions for an organism are found as code in a molecule.

Answer 104

A type of cell division which produces non-identical, haploid cells. It takes place in reproductive organs. Maternal chromosomes = mother Paternal chromosomes = father.

Answer 105

1. Before a cell starts to divide. It duplicates its genetic information(forming two identically armed chromosomes) 2. Then the chromosomes arrange themselves into pairs 3. In the first division the chromosomes line themselves up along the centre of the cell 4. The pairs are then pulled apart to each new cell only has one copy of each chromosome. Some of the fathers and some of the mothers go into that cell. #the mixing up of parents chromosomes is really important as it mixes up their genes, creating genetic variation in the offspring 5. The chromosomes line up along the centre of the cell and the spindle fibres attach to them 6. The spindle fibres pull the chromosome apart and the chromatids are pulled to opposite ends of the cell You get four genetically different, haploid, daughter cells (these are gametes)

Answer 106

1. Vibrations in the air pass down the ear canal. 2. This causes vibrations in the ear drum. 3. These vibrations are passed on to the tiny ear bones. 4. These amplify and transmit them to the cochlea. 5. This contains a long coiled up membrane inside a tube containing a fluid. 6. Vibrations in the fluid make the membrane move. 7. Vibration in the membrane are detected the hair cells (receptors) generate an impulse. 8. Impulses are sent to the brain. 1. Some of the energy transferred through the air is transferred to the ear drum. 2. The changes in pressure at the surface of a solid cause vibrations. 3. The air pressure changes as the sound wave travels. 4. A sound wave causes the particles in the air to move. 5. The vibrations in the particles in the solid are longitudinal.

Answer 107

* Sound waves = longitudinal ○ Therefor particles in a gas move backwards and forwards as a sound wave passes ○ When a sound wave reaches a solid, some energy is transferred is reflected and some is absorbed of transmitted ○ Sound waves cause pressure on the surface of the solid causing it to vibrate and the disturbance is passed from the air to solid. These vibrations can be passed as transverse and longitudinal

Answer 108

* Coiled tube containing a liquid detects the different frequencies of sound reaching the ear(from 20Hz to 20 000Hz) * The parts of the membrane that vibrates depends on the frequencies as different thickness of membranes vibrate best at different frequencies * The thousands of hair cells along the membrane detect its vibrations * Each hair cell is connected to a different neurone that sends impulses to the brain * The brain interprets neurones from different neurones as different pitches of sound.

Answer 109

The ability of an object (or living thing) to do work, to perform an action.

Answer 110

- Gravitational potential energy stores - Kinetic energy stores - Elastic energy stores - Chemical energy stores - Thermal energy stores - Nuclear energy stores

Answer 111

* Electricity * Waves ○ Light ○ Sound ○ Microwaves ○ X-rays

Answer 112

A ball being kicked along the ground = chemical -> kinetic + (thermal) + (sound) Car climbing a hill = Chemical ->kinetic ->gravitational potential + (thermal) A battery-operated motor = Chemical -> kinetic + (thermal) Hydroelectric power station = Gravitational potential -> kinetic -> electrical + (thermal) A chocolate bar being eaten = Chemical -> kinetic + (sound) + thermal A kettle = ?->thermal + (sound)

Answer 113

The diagram shows how much of the input energy is transferred into useful output as well as how much is wasted.

Answer 114

The movement (wave) is perpendicular (at 90 degrees) to the direction of travel.

Answer 115

The movement is parallel to the direction of travel of the wave.

Answer 116

§ They do not need a material particles to travel through. § They transmit energy through force fields § E.g. □ Light waves □ Radio waves □ Microwaves

Science - Term 2 + 2nd half Flashcards

(142 cards)