Science revision please help?

the flow of blood around the body is system used to constantly provide oxygen and other substances need for respiration, and to remove waste products like carbon dioxide from the tissue after respiration. Blood contains oxygen, carbon dioxide, glucose/sugars, platelets, white blood cells, plasma, red blood cells.

water (needed to keep body alive and prevent dehydration), carbohydrates (needed to provide energy to respire and survive), lipids (needed to provide insulation, cushioning for internal organs), fibre (needed to make up bulk of food and prevent constipation), protein (needed to help repair and grow), vitamins & minerals (needed for various body functions and cell parts to keep body alive). Mouth > gullet > stomach > duodenum > small intestine > large intestine > colon > rectum > anus.

Respiratory system is the system that allows the exchange of gases in the lungs by diffusion which allows oxygen to move into the blood and carbon dioxide out.

Respiration is the way the body makes energy in the cells in order to survive. Glucose+Oxygen -> Carbon dioxide+water+energy. You must remember that respiration is NEVER breathing, rather the process in which you make energy in your cells.

Pathogens are harmful microbes. These pathogens are harmful because they release toxins which damage and kill tissue. The body has many ways to fight them. Firstly, our largest organ, the skin, is an impenetrable barrier for pathogens, and sheds often in order to prevent large build ups of microbe colonies on its surface. Another defence mechanism, are platelets. These handy protein molecules latch together in order to 'clot' or cover up or temporarily repair open and damaged blood vessels. Then, you last line of defence are your white blood cells. These cells are in the blood, and different types do different things. The most essential one is the type that 'engulf' the microbe and then digest it. Other types make anti-toxins to counteract the toxins released by the pathogen. Another type are the ones that produce anti-bodies. These anti-bodies help to clump groups of microbes together, or destroy them. Memory white blood cells are able to remember certain pathogens from their antigen*. they will them trigger a release of the same anti-body previously used to kill them. This is called immunity.

*An antigen is the coating on the outside of a cell. Your blood type defines the type of antigen on the outside of your blood cells. When your blood is donated, the body is less likely to reject the blood.

Chemical reaction cover a huge range, and I would not know where to start or what examples to give. However: these are some reactions that do not give exact elements and compounds but are a general reaction for certain instances:

metal+acid -> salt+hydrogen

metal oxide+acid -> salt+water

metal hydroxide+acid -> salt+water

metal carbonate+acid -> salt+water+carbon dioxide.

Rocks are a source of background radiation, though they are rarely radioactive enough to kill us. There are many classifications of rocks. Igneous rock is that which solidifies from molten rock, magma, which is emplaced into or onto the earth's crust by volcanic activity. Sedimentary rocks are those which are formed on the earth's surface by weathering or older rocks. Metamorphic rocks are those which are formed by the high compression and high temperatures placed on older rocks.

Waves come in two forms: longitudinal (like sound waves), and transverse waves (like light). Light is part of the electromagnetic spectrum. It goes from gamma rays > X-rays > ultraviolet > visible light > infrared > microwaves > radio waves. Waves like gamma rays and X-rays have a high frequency, and a short wave length. Microwaves and radio waves have a low frequency and long wave length. The speed of a wave is the frequency time the wavelength. Wavelength is the length of one complete wave. Frequency is the number of waves in a second (measured in Hz). Amplitude is the height of a wave. We humans can hear from around 20Hz to about 20000Hz. Diffraction is the spreading out of a wave as it passes through a gap or round a bend. Refraction is the bending of waves as they pass from one medium to another (e.g. air to glass). total internal reflection in a medium, like glass, can only happen if the angle of incidence is greater than the critical angle of that medium, and only if the medium it is totally internally reflecting in is denser than the medium outside.

- Respiration is Breathing (basically when O2 becomes CO2)

- Dairy helps strengthen bones

- Carbohydrates turn into sugar to create a slow release of energy

- Protein helps your muscles

- White blood cells engulf diseases exept if you have aids which kills off your defensive systen

- The rock cycle includes underwater, erosion, and volcanoes (magma)

Hope I helped!