infection and response

• pathogens are microorganisms that enter the body and cause disease
• pathogens cause communicable diseases
• both plants and animals can be infected by pathogens
• bacteria are very small cells which can reproduce rapidly inside your body
• bacteria can make you feel unwell by producing toxins that damage your cells and tissues
• viruses are not cells
• viruses live and reproduce inside cells, causing cell damage
• pathogens may be viruses, bacteria, protists or fungi
• fungi can be either single celled or have a body made up og hyphae
• a hyphae is a thread - like structure
• hyphae can grow and penetrate human skin and plant surfaces causing diseases
• hyphae can produce spores which can be spread to other plants and animals
• pathogens can be spread by water, air or direct contact
• measles is a viral disease
• symptoms of measles could be fever and a red skin rash
• measles is a serious illness that can be fatal if complications arise so most young children are vaccinated
• measles is spread by inhaling droplets from sneezes and coughs
• HIV is a virus spread by sexual contact or by exchanging bodily fluids like blood which can happen when sharing needles
• HIV causes flu like symptoms
• HIV attacks the bodys immune system
• HIV can be controlled by antiretroviral drugs
• late stage HIV or AIDS occurs when the bodys immune system becomes badly damaged it can no longer deal with other infections or cancers
• tobacco mosaic virus (TMV) is a virus that affects many plants eg. tomatoes
• TMV gives the plant a distinctive mosaic pattern of discolouration on the leaves which affects the growth of the plant due to lack of photosynthesis
• salmonella is a bacterial disease
• salmonella is spread by eating food thats been contaminated with salmonella bacteria
• in the uk, poultry are vaccinated against salmonella to control the spread
• symptoms of salmonella are fever, cramps, vomiting and diarrhoea
• gonorrhoea is a sexually transmitted disease
• gonorrhoea is caused by bacteria
• symptoms of gonorrhoea are thick yellow or green discharge and pain when urinating
• gonorrhoea can be treated with antibiotic penicillin
• the spread of diseases can be reduced / prevented by being hygienic, isolating infected individuals, vaccinating and destroying the organisms that spread the disease
• rose black spot is a fungal disease where purple or black spots develop on leaves, they then turn yellow and drop early
• rose black spot affects the growth of plants as photosynthesis is being reduced
• rose black spot is spread in the environment by water or wind
• rose black spot can be treated by using fungicides or removing affected leaves
• malaria is a disease caused by protists
• malaria protists life cycle happens inside a mosquito
• mosquitos are vectors and they pick up the malarial product when they feed on an infected animal