Biology B1 Notes Essay

Submitted By MasterTyrantX
Words: 712
Pages: 3

B1- Human Biology
Diet and Metabolic Rate:
Regular exercise and a balanced diet are needed to keep the body healthy. Too little food leads to a person being underweight and prone to certain types of illness, while too much food and not enough exercise leads to a person being overweight and other types of ill health.
Carbohydrates- to release energy
Fats- to keep warm, and release energy
Protein- growth, cell repair, cell replacement
Fibre- to help your digestive system
Vitamins and minerals- to keep everything else healthy
People’s energy vary due to how much energy they expend during the day.
Factors effecting health:
• Unbalanced diet
(Peoples diet who’s badly out if balanced are malnourished)
(Malnourished people can be fat or thin)
Eating too much can lead to obesity. Arthritis, type 2 diabetes, high blood pressure, heart disease and some forms of cancer. Too much salt can cause high blood pressure and high blood pressure.
(A bad diet, overeating, and a lack of exercise can cause obesity)
Inherited factors:
Genetic traits can be passed through families in several distinct patterns. Inherited factors are passed on from genes in your DNA. The mutated gene is located on one of the 23 pairs of chromosomes.
Very few health conditions are only caused by genes; most are caused by the combination of genes and environment. The environment includes lifestyle factors, such as diet and exercise. Defending against infection:
Two main types of pathogen:
Bacteria and viruses are the main types of pathogen.
Bacteria are microscopic organisms. They come in many shapes and sizes Bacteria are living cells and, in favourable conditions, can multiply rapidly. Once inside the body, they release poisons or toxins that make us feel ill.
Viruses can only reproduce inside host cells and they damage the cell when they do this. A virus can get inside a cell and, once there, take over and make hundreds of thousands of copies of itself. Eventually the virus copies fill the whole host cell and burst it open.

White blood cells:

Ingest pathogens and destroy them produce antibodies to destroy particular pathogens
Produce antitoxins that counteract the toxins released by pathogens.

Vaccination A vaccine contains
Live pathogens treated to make them harmless
Harmless fragments of the pathogen
Dead pathogens. When injected into the body, they stimulate white blood cells to produce antibodies against the pathogen. If the person does get infected by the pathogen later, their body can respond in the same way as if they had had the disease before. If a large proportion of the population is immune to a particular pathogen, the spread of that pathogen is greatly reduced.
Drugs are substances that change chemical reactions in the body. Medical drugs relieve disease and…