Science Exam Semester 2 - year 9

7 types of electromagnetic waves

1. Radio waves

2. microwaves

3. infrared

4. visible light

5. ultra violet 

6. X-rays

7. gamma rays

Wave Length and frequency of radio waves

Longest wavelengths and low frequency

Microwaves wave length and frequency

long wavelengths and low frequency

The Wavelength and frequency of infrared

Longish wavelength but not that long and frequency is low but not that low(average)

The wavelength of visible light and frequency

Wavelength is average and frequency is average or medium

The wavelength of the ultra violet and frequency

Wavelength getting smaller and frequency getting more often

Wavelength and frequency of X-rays

Wavelength small and frequency often

Wavelength and frequency of gamma rays

Wavelength very small and frequency very often

What is the speed of light?

The speed of light is a constant speed that does not change at all

What is the law of refelction?

1. Convex mirrors have the mirror on the outside of the curve

2. concave mirrors have the mirror on the inside of the curve

Examples of regular reflection

water surface, plane mirror

Examples of irregular reflection

rough wall, bumpy surface

Order of colours in the visible spectrum

ROYGBIV

What is lateral inversion

the horizontal reversal of an image in a plane mirror, where the left side of the object appears as the right side of the image

How does reflection of light determine the colour of an object?

An object's color is determined by which wavelengths of light it reflects, while it absorbs others

Virtual image 

an image between the lense and the focal point will be upright and enlarged. when light doesnt cross-convex mirror, convex lense

Real image

An image formed where light rays converge (join or cross over)

inverted image

• an image that appears upside down in comparison to the object

Upright image

• An image that appears in the same vertical plane as the object 

Concave mirrors common examples

telescopes, makeup mirrors, microscopes

convex mirror common examples

rear view mirrors on cars, road safety mirrors

What is the rule of refraction

When light enters a more dense medium at an angle it is bent towards the normal (because the light slows down).

What is a biconvex lens?

a type of lens with two outward-curving convex surfaces that is thicker in the center than at the edges (oval/diamond look)

biconcave lens?

a lens with two inward-curving (concave) surfaces that is thinnest at the center and thickest at the edges

converging lens

a convex lens that is thicker in the middle and thinner at the edges, designed to bend parallel light rays inward to meet at a focal point

diverging lens

is also known as a concave lens, is an optical lens that causes parallel rays of light to spread out (diverge) as they pass through it

What happens with refraction in a pool of water?

Its causes objects underwater to appear closer or slightly bent because the light bends as it travels

Dispersion of white light 

white light seperates into colours (ROYGBIV)

How do we see things?

through a process involving light reflecting off objects and entering our eyes, where the image is processed by the brain to create a visual perception

Why do we see colour/brightness

because light enters our eyes and is detected by photoreceptor cells in the retina, called rods and cones

How does they eye work?

convert light into electrical signals that are interpreted by the brain as images

cornea

Clear window, refracts light, helps to focus the light

pupil

Hole in the iris, which allows light to enter the eye

iris

Coloured, changes size to control the amount of light entering the eye

lens

Refracts light to focus image on the retina. Focal length adjusted by ciliary muscles

retina

light sensitive cells (rods & cones) which change light energy to nerve impulses.

optical nerve

Takes messages from the retina to the brain

sclera

The white, tough outer layer that protects the eye.  

liquid humour

Watery at the front, jelly at the back, helps to keep eye’s shape and provide medium for light to travel through.

what role does the eye play in sight

The eye functions as an optical system, first capturing light with the cornea, then controlling the amount of light that enters with the pupil and iris

What parts of the eye will light pass through tostrike the retina?

cornea,pupil,iris

2 vision defects

• blurred vision

• lazy eye

Describe an ecosystem

a community of living organisms (biotic factors) interacting with each other and their non-living environment (abiotic factors) like water, soil, and weather

Abiotic

non-living parts of the enviroment

Biotic

living organisms

Autotrophs

creates its own food

heterotrophs

feeds off other organisms

xylem

transports water from the roots to the leaves

phloem

transports food from the leaves to the rest of the plant

stoma

allow carbon dioxide to enter and oxygen to be released from the leaf

Guard cells

open and close the stomata

Palisade Mesophyll

contain a large amount of chloroplasts Spongy Mesophyll:

Spongy Mesophyll

gaseous exchange

How is water, nutrients, and sugar transported in plants?

The xylem moves it all up to the leaves and the Sugar (glucose) and amino acids are transported to where they are needed, both up and down the plant, through the phloem

Where does photosynthesis occur

chloroplasts

What is required for photosynthesis to occur

sunlight

Where does cellular respiration occur?

begins in the cytoplasm with glycolysis, then moves to the mitochondria

What is required for cellular respiration to occur?

glucose &/ or oxygen

what is areobic respiration?

the process by which cells break down glucose in the presence of oxygen to produce a large amount of usable energy in the form of ATP

Areobic respiration worded equation?

Glucose + oxygen ➔ carbon dioxide + water + energy (ATP)

what is anaerobic respiration?

process that generates energy (ATP) in the absence of oxygen

what is the worded equation for anaerobic respiration?

Glucose  ➔ lactic acid + energy (ATP)

What is a food chain?

sequence that shows how energy is transferred when one organism eats another

What is a food web?

Its a diagram that shows the sequence that shows how energy is transferred when one organism eats another

How is energy lost and transferd as it moves through trophic levels?

Energy is lost as heat during cellular respiration is also lost

Producers

Producers make there own food

consumers

Eat other organisms to gain energy

dependant variable

The variable that is being measured

independant variable

Thing that is being changed in the experiment

controlled varibables

Things that stay the same in the experiment

Mistakes

personal error

systematic errors

errors the cause the results to be different by the same amount each time

Random errors

Errors that result in completely different results every time