infection and response

What is a pathogen?

A microorganism that causes disease

Name the four main types of pathogen. Bacteria, viruses, fungi, protists

How do bacteria cause illness? By producing toxins that damage cells and tissues

How do viruses cause illness? By invading and reproducing inside cells, causing cell damage

Give an example of a bacterial disease. Salmonella food poisoning

Give an example of a viral disease. Measles

Give an example of a fungal disease. Athlete’s foot

Give an example of a protist disease. Malaria

What is communicable disease? Disease that can be spread between organisms

Which body system acts as the first line of defense? The skin and mucous membranes

How does skin protect against infection? Acts as a physical barrier, secretes antimicrobial substances

How does the nose protect against pathogens? Hairs and mucus trap particles

How do the trachea and bronchi protect against pathogens? Mucus traps particles; cilia waft it up to throat

How does the stomach protect against pathogens? Hydrochloric acid destroys most pathogens

What is phagocytosis? Process where white blood cells engulf and digest pathogens

What are antibodies? Proteins made by white blood cells to target specific pathogens

How do antibodies help fight infection? Bind to antigens, marking pathogens for destruction

What are antitoxins? Chemicals produced by white blood cells to neutralise toxins

What is vaccination? Introducing small amounts of inactive pathogens to stimulate antibody production

What does herd immunity mean? If a large proportion are immune, spread of disease stops

What is an antibiotic? Drug that kills bacteria but not viruses

Why can't antibiotics treat viral infections? Viruses replicate inside cells, making them hard to target

What is antibiotic resistance? When bacteria evolve to survive antibiotics

Give one example of antibiotic resistance. MRSA

How can antibiotic resistance be prevented? Only prescribe when necessary; finish full course

What is painkiller? Drug that relieves symptoms but does not kill pathogens

Why is drug testing important? Ensures safety and effectiveness of medicines

What is preclinical testing? Testing on cells, tissues, and animals

What is clinical testing? Trials on healthy volunteers and patients

What is a double-blind trial? Neither patient nor doctor knows who gets real medicine

What is a placebo? A harmless, inactive substance given instead of real medicine

What is monoclonal antibody? Identical antibodies produced from a single clone

What is a hybridoma cell? Fusion of a mouse immune cell and tumour cell used for making monoclonal antibodies

Give a use of monoclonal antibodies in medicine. Diagnosing disease or treating cancer

How are monoclonal antibodies used in pregnancy tests? They bind to pregnancy hormones in urine

What are symptoms of measles? Fever, red rash

How is measles spread? Through droplets in the air from coughs and sneezes

Why can measles be serious? It can lead to complications like pneumonia or brain infection

How is HIV transmitted? Sexual contact, exchange of bodily fluids

What does HIV attack? Immune system's white blood cells

What is AIDS? Late stage HIV infection when immune system is severely damaged

Why are people with AIDS at risk? Their immune system cannot fight infections

What is rose black spot? Fungal disease affecting rose plants

What are the symptoms of rose black spot? Purple/black spots on leaves, leaves turn yellow and drop

How is rose black spot spread? Water or wind

How is rose black spot treated? Fungicide or removing affected leaves

What is malaria? Disease caused by protist spread by mosquitos

What is vector in malaria? The mosquito, which carries and transfers the protist

How can malaria be prevented? Mosquito nets, insecticides, removing standing water

What is non-specific defense? General barriers (skin, mucus, etc.) against all pathogens

What is specific defense? Targeted immune response by lymphocytes

How do white blood cells defend against infection? Engulf pathogens, produce antibodies and antitoxins

What is an antigen? Unique protein on a pathogen’s surface

What triggers antibody production? Presence of antigens on invading pathogens

How do memory cells help immunity? They remember pathogens for faster future response

What is herd immunity? When enough people are immune to protect the whole population

How are epidemics controlled? Immunisation, isolation, hygiene measures

Why are vaccines updated? Pathogens can mutate and change antigens

What is pandemic? Widespread disease outbreak affecting many countries

Give one example of a pandemic. COVID-19

Why can new diseases spread quickly? No existing immunity – no vaccine or antibodies

What is clinical trial? Test of drugs on humans to determine safety and effectiveness

Why are drugs tested on animals first? To check safety before human use

What are the stages of drug development? Lab studies, preclinical tests, clinical trial, approval

What is dose? The amount of drug given

What is toxicity? How poisonous or harmful a drug is

What is efficacy? How well a drug works

Why do doctors use double-blind trials? To avoid bias in results

What is a side effect? Unwanted effect of a drug or treatment

What is placebo effect? Improvement due to expectation, not real drug

How can people reduce the spread of infection? Hand washing, covering mouth, clean surfaces, isolate sick

What is antiseptic? Substance that kills pathogens on living tissue

What is disinfectant? Substance that kills pathogens on surfaces

Give one example of a disinfectant. Bleach

What is immunity? Ability to resist and recover from infection

What is active immunity? Immunity gained by exposure to disease (or vaccine)

What is passive immunity? Immunity from another source, e.g. maternal antibodies

Name a disease prevented by vaccination. Polio

Why is polio almost eradicated? Effective global vaccination program

How do pathogens enter the body? Cuts, mouth, nose, eyes, ears, bites

What is epidemic? Sudden outbreak of disease in one area

Why is genetic engineering used in medicine? For making insulin, vaccines

How do painkillers differ from antibiotics? Painkillers relieve symptoms, antibiotics kill bacteria

What is a prescription drug? Medicine only available with a doctor's approval

Why do some medicines come in different forms? Pills, injections, creams — for different uses/absorption

What is resistance in pathogens? Ability to survive treatments that once killed them

How does antibiotic resistance develop? Overuse and misuse encourages resistant strains

What is infection? Growth and spread of pathogens in the body

Name a bacterial infection. Tuberculosis, Salmonella, Cholera

Describe one viral infection. Influenza: causes fever, cough, aches

Name a symptom of plant disease. Changed leaf color, spots, wilting

How can plant diseases be identified? Laboratory tests, symptom observation, monoclonal antibodies

Why is disease monitoring important? Detect outbreaks, protect public health

How do vaccines protect individuals? Stimulate antibody production for immunity

What is a chronic infection? Long-lasting, ongoing infection

What is an acute infection? Sudden, short-term infection

Why must vaccine doses sometimes be repeated? To boost immunity

Why is hygiene important? Prevents transmission of pathogens

What is zoonosis? Disease spreading from animals to humans