biology

what are genes? short section of DNA 

how many chromosomes have we got 23 pairs

what the heart is made up of?

ARTERIES carry blood AWAY from the heart TOWARDS the organs. 

CAPILLIRIES allow food and oxygen to diffuse to cells while waste is diffused from cells.

what can cause heart failier?

High blood pressure is the biggest concern as it increases the risk of a heart attack

A heart attack can happen because:

·         Fatty deposits build up in the coronary arteries

·         A blood clot can form on a fatty deposit

·         The blood clot can block a coronary artery

·         Some heart muscle cells do not get the oxygen and nutrients the need

·         These cells start to die

It is achieved by balancing bodily inputs and outputs, using the NERVOUS SYSTEM and HORMONES to control the process. Examples if things that the body keeps the same are:

·         Body temperature at 37˚C

The amount of water inside our body

·         When the water level of our BLOOD PLASMA is LOW, more  water is reabsorbed back into the blood and the urine becomes more CONCENTRATED

The concentration of urine is controlled by a hormone called ADH, which is released into the bloodstream by the PITUITARY GLAND.

BIODIVERSITY refers to the variety of life on Earth including:

·         The number of different species in an area

·         The range of different types of organisms, e.g. plants, animals and microorganisms

·         The genetic variation within species (how many different alleles there are)