Year 9 science

Year 9 science exam mid term october 2024

Biology-9Aa- environmental variation:

Biology-9Aa- environmental variation:

environment

An organisms surroundings

Environmental factors

any factors that influences living organisms

Environmental variation

variation caused by an organism’s environment

Continuous variation

variation that can have any value between two points

Discontinuous variation

variation that can only have a value from a limited set of possible values

9Ab-Inherited variation:

-9Ab-Inherited variation:

Inherited variation

differences between organisms passed on to offspring by their reproduction

Genetic information

the instructions of inherited characteristics

Genes

the instructions of inherited characteristics are found in genes

Nucleus

the genes are inside the nucleus

9Ab-Probability:

-9Ab-Probability:

Probability

is the chances of something to happen

9Ac-DNA:

-9Ac-DNA:

DNA is found in structures called...

chromosomes

A human cell contains__chromosomes

46

Sex chromosomes

female have xx and male xy ,y is shorter than x

Gamete only have__chromosomes

23

when gamete from male and egg from female fuse...

our zygote and embryo have 46 chromosomes in our DNA

from cell to genes

Cell>nucleus>chromosome>DNA>genes

9Ad-Genes and extinction:

-9Ad-Genes and extinction:

Food webs

many food chains linked together, showing the flow of energy through organisms in a habitat

Biodiversity

the range of different species of organisms in an area

Gene bank

Any facility that stores genetic material from organisms

9Ae-Natural selection:

-9Ae-Natural selection:

Natural selection

a process in wich an organism is more likely to survive and reproduce than other members of the species because it possesses a certain inherited variation

Evolution

A change over time in the characteristics of organisms

9Ae-Recreating animals:

9Ae-Recreating animals:

Some scientists think that experiment for cloning mammoths with DNA will not ...

behave like a real one, so the experiment will not be valid

We can found ...

DNA in frozen mammoths

Chemistry

Chemistry

9Ea- Materials of the future:

9Ea- Materials of the future:

Independent variable

The value you chose

Dependent variable

varies because the independent variable and is the variable you are measuring

9Ea -About ceramics:

9Ea -About ceramics:

Ceramics are a range of ...

hard, durable,non-metallic materials, which are generally unaffected by heat.

The raw materials for traditional ceramics are ...

clay and sand

Clay is heated

chemical reactions occur and new compounds are formed

9Eb -Polymers:

9Eb -Polymers:

Polymer

a long-chain molecule made up of repeating groups of atoms

Atoms are held together by ...

(forces of attraction called) bonds

Vulcanization of rubber

vulcanization is a process that changes synthetic and natural rubber into cross-linked polymers

Exothermic reactions

Reactions that transfer energy to the surroundings

Endothermic reactions

Reactions that absorb energy from the surroundings making them cooler

9Eb -Peer review (WS):

9Eb -Peer review (WS):

Peer review

the process by which scientific papers are checked by other scientists, by repeating the experiments and checking the conclusions drawn from the results

The purpose of peer review is to ...

check the methods, results, conclusions and originality of a scientific paper.

9Ec -Composite materials:

9Ec -Composite materials:

Composite materials

a material made up of two or more materials, the separate materials don’t react together

Fibre

a long thin continuous strand or thread/Fibre in composite materials is like the strong threads in a fabric.

These fibres, which can be made from materials like glass, carbon, or even natural sources like plants, are combined with a ...

glue-like substance called a matrix (often a type of resin).

Concrete

artificial stone made from a mixture of cement, sand, aggregate (crushed rocks) and water.

Cement

a substance that binds materials together, in buildings it refers to a mixture of clay and lime(calcium oxide)

9Ec -Materials for cars:

9Ec -Materials for cars:

(Polymers)Poly

many (Monumer)Monu

Steel is the ...

best material for cars

9Ed -Problems with materials:

9Ed -Problems with materials:

Manufacturing materials usually ...

uses energy released by the combustion of fossil fuels.

Acid rain is made by ...

sulfur oxide,

acid rain kills ...

trees

This can damage the environment

■ carbon monoxide ■ sulfur dioxide■ carbon dioxide

Incomplete combustion can be reduced by ...

increasing the amount of oxygen available during combustion.

Toxic substances/water pollutants

Pollutants are released into water from the factories, The pollutants then get into the fish. Humans then eat the fish that contain the pollutants.

Biodegradability

Many modern materials are designed to last for a long time and not to break down naturally.

9Ee -Recycling materials:

9Ee -Recycling materials:

Recycling

using the same materials again and again.

By recycling materials we reduce our ...

use of limited resources, save fuel and energy costs and reduce the use of landfill sites.

Recycle metals

you can melted to be moulded in new metal objects

Recycle glass

separate the glass by colours crush it and melted to be moulded in new glass objects

Recycle paper

wash and remove ink, strain it, heat it and mix it, squeeze and dry

Recycle concrete

use large crushing machines until it is aggregate(crushed rocks)

Recycle polymers

polymers have a stamp to identify the different types of polymers, polymers have a low level of recycle

9Ee -Material failures:

9Ee -Material failures:

Physics-9Ia Moving things

Physics-9Ia Moving things

9Ia Forces and movement

9Ia Forces and movement

Drag forces

drag forces act to slow down objects moving trough fluids

9Ia Energy for movement

9Ia Energy for movement

Energy is never created or destroyed, but only ...

transferred

Electricity cannot be ...

stored

non-renewable

resource it will run out one day.

renewable

it will never finish

Gravitational potential energy

energy stored in raised objects

Kinetic energy

Anything that is moving

Elastic potential energy

energy stored in stretched or squashed things that can change back to their original shape

Internal energy

the energy stored in the movement of particles

9Ic Speed

9Ic Speed

Speed

a way of saying how far you can travel in a certain time. This time can be a second (s), a minute (m), an hour (h), or even longer.

Convert a speed in m/s to km/h by ...

dividing by 1000 and then multiplying by 3600

Convert a speed in km/h to m/s by ...

multiplying by 1000 and then dividing by 3600

Mean average speed

is the total distance traveled, divided by the time taken

9Ic Equations and graphs (WS)

9Ic Equations and graphs (WS)

Relative speed

the speed of one object compared to another(Both objects could be moving)

kinetic energy

energy that is moving