biology revison year 10

Infection and response 

key terms: 

communicable disease - can be transmitted from one person to another (e.g measles) 

non-communicable disease - cannot be transmitted from one person to another (e.g cancer) 

pathogens - micro-organsims that cause disease (e.g viruses, bacteria, fungi and protists) 

bacteria produce toxins that damage our cells

viruses live inside and reproduce inside our cells causing damage to the cell 

viral diseases: 

measles - a viral disease whose symptoms are a res skin rash and a fever. It is spread through inhalation of droplets from coughs and sneezes. Measles can be a serious illness so most children are vaccinated 

HIV - a viral disease spread by the following 

         unprotected sexual intercourse with an infected person 

a baby breastfeeding from an infected mother

a blood transfusion from a blood donor with HIV 

sharing needles with an infected person 

HIV initially causes a flu-like illness but in the long term attacks the immune system leaving it unable to fight other illnesses. It can be trerated with anti-viral drugs but these do not cure the disease.

tobacco mosaic virus (TMV) - affects many species of plants including tobacco plants and tomatoes. It causes a mosaic discolouration on the leaves. This reduces the area of the leaf that can carry out photosynthesis so reduces plant growth.

Bacterial diseases:

Gonorrhea - a sexually transmitted disease whose symptoms include a green or yellow discharge from the vagina or penis and pain when urinating. Can be treat with antibiotics.If left untreated it can result in infertility and ectopic pregnancy. Can be prevented by use of condoms

Salmonella - caused by eating undercooked food. In the UK poultry are vaccinated against Salmonella to reduce the spread. Symptoms include vomitting, fever and abdominal cramps.

Fungal Diseases:

Rose black spot affects rose plants causing black or purple spots on leaves. Reduces photosynthesis and growth. Can be treated with a fungicide. Spread by wind and rain and by removing affected leaves. 

Protist Diseases: 

Malaria - symptoms are a recurrent fever and the disease can be fatal. Spread by a vector, a female mosquito. Prevention is by affecting the life cycle of the vector by removing its habitat. Bed nets can also…