B3: Infection and Response Flashcards
What is a communicable disease
A disease caused by a pathogen which can be passed down between animals or plants eg. Flu
What is a pathogen?
A disease-causing microorganism e.g. bacteria
How do bacteria cause disease?
- inside the body, they divide rapidly by binary fission.
- They kill cells and produce harmful toxins
How do viruses cause disease?
- they invade and reproduce inside living body cells, leading to cell damage
Give three ways in which pathogens can be spread and examples
- by air - flu, tuberculosis and the common cold are spread by droplet infection
- by water- fungal spores in water spread plant disease
- by direct contact - common in plant diseases and sexually transmitted infections
Give four ways in which the spread of pathogens can be reduced
- Hygiene: handwashing, disinfectants,
- reducing contact with infected individuals: quarantine
- removing vectors: use of pesticides and insecticides, removal of habitats
- vaccination
Why is it important to prevent the spread of viral disease?
- scientists have not yet developed cures for many viral diseases
.Define ‘health’.
State of physical and mental well-being
What is measles? Give the main symptoms
- Measles is a serious viral disease that can cause blindness and brain damage
- fever and a red skin rash
how is measles spread ?
by air: through the inhalation of droplets from coughs and sneezes
What is HIV?
- A virus which attacks and damages the immune system until it can no longer function properly
What is AIDS?
AIDS: condition resulting from a long-term HIV infection
How is HIV spread?
- Direct sexual contact
- the exchange of bodily fluids e.g. blood, breastmilk
Give 5 ways the spread of HIV/AIDS be prevented?
- use of condoms
- screening of blood for transfusions
- not sharing needles
- bottle-feeding by HIV-positive mothers
- use of antiretroviral drugs to prevent the development of AIDS
What is tobacco mosaic virus?
- A plant pathogen which causes leaf discolouration when cells are damaged.
- Affected areas cannot photosynthesise , reducing the crop yield
How is tobacco mosaic virus spread ?
- contact between infected and healthy plants
- insects may act as vectors which transfer the virus between different plants
What is salmonella?
- A type of bacteria found in raw meat, poultry and eggs.
- If they enter the body via food poisoning , they can affect natural gut bacteria
Give 4 symptoms of salmonella food poisoning?
- fever
- abdominal cramping
- vomiting
- Diarrhoea
May be fatal in very young or elderly populations due the risk of dehydration
Give four ways the spread of salmonella be limited?
- vaccinating animals intended for consumption
- keep raw meat away from cooked meat
- disinfect hands and surfaces after contact with raw meat
- thoroughly cook meat
What is gonorrhoea?
- A sexually transmitted bacterial infection caused by unprotected sex with an infected individual
Give symptoms of gonorrhoea
- yellow/green discharge from genitals
- painful urination
State 3 long-term effects of gonorrhoea.
- Long-term pelvic pain,
- infertility
- ectopic pregnancies
give three ways the spread of gonorrhoea be
stopped?
- Use condom
- Limit sexual partners
- spread can be controlled through the use of antibiotics
what is rose black spot?
- A fungal disease which causes purple or black spots to develop on rose leaves
- it reduces the area of the leaf which is available for photosynthesis and causes leaves to turn yellow and drop prematurely
How is the rose black spot fungus spread?
- fungal spores are spread by the wind and in water
Give two ways the rose black spot fungus can be treated?
- using fungicides
- destroying infected leaves
.How can we use Agrobacterium tumefaciens
in plants?
They cause galls –> genetic manipulation
What is malaria?
- Malaria is a disease caused by protist pathogens
- the disease is carried from host to host by mosquitoes , and the protists enter the human bloodstream when they feed
Give symptoms of malaria
- fever
- shaking
Give four ways the spread of malaria be reduced
- using insecticides
- using insect nets to avoid bites
- prevent mosquito breeding by removing stagnant water
- antimalarial drugs
Give four ways the skin prevents pathogens from entering the body
- acts as a physical barrier
- scab formation after skin is cut/wounded
- antimicrobial secretions which can kill pathogens
- healthy skin flora compete with pathogens and act as an additional barrier
Give two ways the respiratory system prevent pathogens from entering the body
- nose - has hairs and mucus which trap pathogens
- trachea and bronchi- have mucus that traps pathogens. Ciliated cells move mucus to the mouth so it can be swallowed