Biology B1 Notes for Aqa
Year 9 Biology Notes
Keeping Healthy Test * Metabolic Rate- How quickly the chemical reactions (metabolism) are taking place within cells * In a balanced diet, you need- -Carbohydrates to build cells and to release energy. -Minerals and Vitamins in small amounts to keep the body functioning. -Water because we lose 70% form sweat, breath, tears, urine, faeces etc. -Fibre to prevent constipation and bowel cancer. * Malnutrition- eating a diet which is not balanced which can lead to being overweight (obese), underweight or deficiency diseases (Rickets etc) * Pathogens- Infectious diseases carried by microorganisms which can be passed form one person to another. * Bacteria- Single-celled organisms. Cause diseases by reproducing rapidly once inside the body (Splitting). They produce Toxins * Viruses- Take over the cells as they reproduce, damaging and destroying them, very rarely produces toxins. * How the body protects from Pathogens: -Skin covers body and acts as a barrier. -Scabs- Platelets in your blood quickly help to form a clot which dries into a scab which stops Pathogens. -Mucus- when you breathe, you draw air loaded with Pathogens. However, your breathing organs produce a sticky liquid. * -Stomach Acid- When the mucus gets swallowed into the gut, stomach destroys the pathogens * Immune System- White blood cells can protect us by: -Ingestion-Some white blood cells actually take in Pathogens, destroying and preventing them form causing disease -Antitoxins- Some white blood cells produce Antitoxins. These counteract the toxins (poisons) released by Pathogens -Antibodies- White blood cells release a chemical called an Antibody, which destroys the Pathogen. A unique antibody is released to destroy each type of Antibody * Mutations- Random/Naturally occurring changes which happen in the genes of organisms which change their characteristics * Immunity- Our white blood cells are able to
Keeping Healthy Test * Metabolic Rate- How quickly the chemical reactions (metabolism) are taking place within cells * In a balanced diet, you need- -Carbohydrates to build cells and to release energy. -Minerals and Vitamins in small amounts to keep the body functioning. -Water because we lose 70% form sweat, breath, tears, urine, faeces etc. -Fibre to prevent constipation and bowel cancer. * Malnutrition- eating a diet which is not balanced which can lead to being overweight (obese), underweight or deficiency diseases (Rickets etc) * Pathogens- Infectious diseases carried by microorganisms which can be passed form one person to another. * Bacteria- Single-celled organisms. Cause diseases by reproducing rapidly once inside the body (Splitting). They produce Toxins * Viruses- Take over the cells as they reproduce, damaging and destroying them, very rarely produces toxins. * How the body protects from Pathogens: -Skin covers body and acts as a barrier. -Scabs- Platelets in your blood quickly help to form a clot which dries into a scab which stops Pathogens. -Mucus- when you breathe, you draw air loaded with Pathogens. However, your breathing organs produce a sticky liquid. * -Stomach Acid- When the mucus gets swallowed into the gut, stomach destroys the pathogens * Immune System- White blood cells can protect us by: -Ingestion-Some white blood cells actually take in Pathogens, destroying and preventing them form causing disease -Antitoxins- Some white blood cells produce Antitoxins. These counteract the toxins (poisons) released by Pathogens -Antibodies- White blood cells release a chemical called an Antibody, which destroys the Pathogen. A unique antibody is released to destroy each type of Antibody * Mutations- Random/Naturally occurring changes which happen in the genes of organisms which change their characteristics * Immunity- Our white blood cells are able to