Biology Revision Notes

Only available on StudyMode
  • Download(s) : 87
  • Published : May 28, 2013
Open Document
Text Preview
Biology End of Year Revision

Quick Recap on Graphs:
* Always remember to include units
* Put the dependent (thing you measure) along the y-axis. (One going up) * Put the independent (thing you change) on the x-axis (along the bottom) * Don’t join the dots up, draw a line of best fit.

* Circle anomaly result.

Healthy Diet
For a healthy diet, you need energy. So you need:
CARBOHYDRATES, to release energy.
FATS, to keep warm and release energy
PROTEIN, for growth cell repair and cell replacement.
FIBRE, to keep everything moving smoothly through your digestive system. VITAMINS and MINERALS in small amounts, to keep your skin, bones blood and everything healthy.

You need energy to fuel the chemical reactions in the body that keep you alive. These reactions are called your METABOLISM. And the speed at which they occur is called your METABOLIC RATE.

Different people have different resting metabolic rates. Eg, muscle need more energy than fatty tissue so people with a higher proportion of muscle to fat will have a HIGHER metabolic rate.

Physically bigger people also will have a higher metabolic rate because their bodies need more energy. Men tend to have a higher metabolic rate than women-because they’re bigger and have a larger proportion of muscle. Regular exercise can boost your metabolic rate because it builds muscle.

People whose diet is badly unbalanced are said to be MALONOURISHED. This can be too FAT or too THIN. Eating too much can lead to obesity: * Excess carbs or fat in the diet can lead to being overweight. * Obesity is being over 20%of your maximum recommended body mass. * Usual cause is bad diet, over-eating and lack of excersise. * Health problems can arrive such as ARTHIRITUS,TYPE 2 DIABETES,HIGH BLOOD PRESSURE and HEART DISEASE.

Inherited factors- your health can depend on inherited factors too. Some people may inherit factors that effect their metabolic rate e.g. Causing underactive thyroid gland, which can cause obesity.

Others may inherit factors that affect their BLOOD CHOLESTEROL LEVEL. Cholesterol is a fatty substance that is essential for good health. It’s found in every cell in the body. Some inherited factors increase the blood cholesterol level, which increases the risk of heart disease. STATINS are prescribed to lower the cholesterol level. If you don’t get enough of something it can cause a DEFFICIENCY DISEASE.

Body Mass Index
The sum to work this out is: mass
--------------
(Height)2
Losing Mass is when the energy content of the food taken in is less than the amount of energy used (expended).

Normal Weight= 18.4 – 24.9 Kg
Overweight= 25 – 29.9 Kg
Obese= Over 30 Kg

Evaluating food is looking at the claims and how much of stuff is in the food e.g. fat.

Diseases
The microbes which cause infectious diseases are know as PATHOGENS. Once BACTERIA and VIRUSES get inside your body they REPRODUCE rapidly. They DAMAGE your tissues and may produce TOXINS, which cause the SYMPTOMS of disease.

Two main types of pathogen are:
* BACTERIA- These are very small cells which can reproduce rapidly inside your body. They can make you feel ill by damaging your cells, and producing toxins(poison) * VIRUS-These are not cells. They replicate themselves by invading your cells and using the cells ‘machinery’ to produce many copies of themselves. The cell will usually burst,releasing all the new viruses. This cell damage is what makes you feel ill. * Defense against Pathogens:

Your skin, plus hairs and mucus in your respiratory tract stop nasty things getting inside your body. Blood clots quickly on cuts to stop harmful things getting under your skin. If something makes it through this is where your immune system kicks in.

The body has different ways of protecting itself against pathogens. White blood cells help to defend against pathogens by… *...
tracking img