infection and response

• measles is a serious disease caused by a virus that shows symptoms of fever and red skin rash
• a pathogen is a microorganisms that cause infectous disease
• preclinical drug testing done in a laboratory using cells, tissues and live animals
• rose black spot is a fungal disease where purple or black spots develop on leaves, which often turn yellow and drop early
• salmonella is a bacterial disease that is spread by bacteria ingested in food and can cause a fever, abdominal cramps, vomiting and diarrhea
• tobacco mosaic virus is a widespread plant pathogen that causes yellowing of leaves and stunted growth
• vaccination is the process of introducing small quantities of dead or inactive forms of a pathogen into the body to stimulate the white blood cells to produce antibodies
• antibiotics are medicines that help to cure bacterial diseases by killing infective bacteria inside the body
• clinical drug testing is done on healthy human volunteers and patients
• a double blind trial is a study performed where neither the researcher or patient know whether the patient is taking the drug or a placebo
• malaria is a disease caused by protists that causes recurrest episodes of fever and can be fatal
• HIV is an infectous virus that weakens the immune system and can leave to aids
• gonorrhea is a sexually transmitted disease caused by a bacterium with symptoms of a thick yellow or green discharge from the vagina or penis and pain when urinating
• communicable disease is a disease that can be spread between individuals either directly or indirectly
• plant defences of pathogens are cellulose cell walls, a touch waxy cuticles on leaves and layers of dead cells around stems
• the immune system prevents pathogens through: phagocytosis, antibodies and antitoxins
• phagocytosis is where the pathogen is engulfed and digested
• antibodies attach to antigen molecules
• antitoxins are chemicals that neutralise poisonous effects on toxins
• non-specific defence are general physical and chemical barriers that defend the body against lots of different types of pathogen
• white blood cells are an important type of cell that make up the immune system and produce antibodies and antitoxins
• a placebo is a substance designed to be indistinguisable from a drug being tested but has no actual effect on the patient
• a benign tumour is an abnormal cell growth that is contained within one area and does not invade other areas of the body
• a non-communicable disease is a disease which cannot be spread between individuals
• a malignant tumour is a cancerus cell growth that inades neighbouring tissues and can spread to different parts of the body in the blood
• cancer is a non communicable disease caused by changes in the cell that leads to uncontrolled growth and divisions
• smoking increases the risk of lung cancer due to tar deposits in lungs
• lung cancer symptoms include cough, breathlessness, chest pain, weight loss and tiredness
• radiotherapy uses radiation to kill cancer cells