Infection and response full set

What are pathogens?

Microorganisms that cause disease.

Name the four types of pathogens.

Bacteria, viruses, fungi, and protists.

How do bacteria cause disease?

By producing toxins that damage cells and tissues.

How do viruses cause disease?

By invading cells, replicating, and bursting them.

How do fungi cause disease?

Some grow hyphae that penetrate tissues, causing infection.

How do protists cause disease?

By living inside hosts and damaging cells.

What are communicable diseases?

Diseases that can be spread between organisms.

Give three ways pathogens can be spread.

Through air, water, and direct contact.

What is an example of an airborne disease?

Influenza (flu).

How does water spread disease?

By drinking or bathing in contaminated water.

Give an example of a disease spread through direct contact.

Gonorrhea.

What is a vector?

An organism that spreads disease without getting infected.

Give an example of a disease spread by a vector.

Malaria (spread by mosquitoes).

What are some natural defences against disease in the human body?

Skin, mucus, stomach acid, and the immune system.

Why do white blood cells produce antibodies?

To bind to specific pathogens and help destroy them.

What is a vaccine?

A weakened or dead form of a pathogen that stimulates immunity.

How do vaccines prevent disease?

They train the immune system to recognize and respond quickly to future infections.

Why do some diseases require booster vaccinations?

To maintain immunity as antibody levels decline.

What is herd immunity?

When enough people are vaccinated, reducing disease spread.

What is an example of a viral disease?

Measles.

How is measles spread?

Through droplets from coughs and sneezes.

What are the symptoms of measles?

Fever and a red skin rash.

How is HIV transmitted?

Through bodily fluids like blood or sexual contact.

What does HIV do to the immune system?

Weakens it, making the body vulnerable to infections.

What can untreated HIV lead to?

AIDS (Acquired Immunodeficiency Syndrome).

How is HIV controlled?

With antiretroviral drugs.

What is tobacco mosaic virus (TMV)?

A plant virus affecting photosynthesis.

What is an example of a fungal disease?

Rose black spot.

How does rose black spot spread?

By wind and water.

How is rose black spot treated?

By using fungicides and removing infected leaves.

What is malaria caused by?

A protist.

How is malaria transmitted?

Through mosquito bites.

What are the symptoms of malaria?

Repeated episodes of fever.

How can malaria be prevented?

Using mosquito nets and insecticides.

What is an example of a bacterial disease?

Salmonella.

How is salmonella transmitted?

Through contaminated food.

What are the symptoms of salmonella?

Fever, vomiting, and diarrhea.

How is salmonella prevented?

Vaccination of poultry.

What is gonorrhea?

A sexually transmitted bacterial disease.

What are the symptoms of gonorrhea?

Painful urination and discharge.

How is gonorrhea treated?

With antibiotics.

Why is antibiotic resistance a problem?

It makes infections harder to treat.

What causes antibiotic resistance?

Overuse and misuse of antibiotics.

What is an example of an antibiotic-resistant bacterium?

MRSA (Methicillin-resistant Staphylococcus aureus).

How can the spread of disease be prevented?

Vaccination, good hygiene, and isolation.

What is the function of white blood cells?

To fight infections.

What are antitoxins?

Substances that neutralize toxins produced by bacteria.

How does the skin prevent infection?

It acts as a physical barrier.

What is the role of mucus in the nose?

To trap pathogens.

How does stomach acid protect against infection?

It kills bacteria in food.

What is the function of platelets?

To clot blood and seal wounds.

What are antibiotics used for?

Treating bacterial infections.

Why don’t antibiotics work on viruses?

Viruses reproduce inside human cells, making them harder to target.

What is the purpose of painkillers?

To relieve symptoms but not cure the disease.

What was penicillin discovered from?

A mold.

What is the first stage of drug development?

Testing on human cells and tissues.

Why are drugs tested on live animals?

To check for toxicity and effectiveness.

What happens in clinical trials?

Drugs are tested on healthy volunteers and patients.

Why are low doses used in early clinical trials?

To ensure safety.

What is a placebo?

A fake treatment used in trials to test real drug effects.

Why are double-blind trials important?

To eliminate bias.

What is the purpose of peer review in drug testing?

To check reliability and accuracy.

What are monoclonal antibodies?

Lab-made identical antibodies designed to target specific cells.

How are monoclonal antibodies made?

By fusing a mouse B-lymphocyte with a tumor cell.

What is a hybridoma cell?

A fused B-lymphocyte and tumor cell that produces antibodies.

What is a use of monoclonal antibodies?

In cancer treatment and pregnancy tests.

How do monoclonal antibodies help diagnose diseases?

They bind to specific antigens in blood tests.

What is an advantage of monoclonal antibodies?

They target only diseased cells, reducing side effects.

What is a disadvantage of monoclonal antibodies?

They can cause immune reactions.

What is a plant disease example?

TMV (Tobacco Mosaic Virus).

How do aphids harm plants?

By sucking nutrients from them.

What are signs of plant disease?

Stunted growth, spots, or abnormal leaves.

How can plant diseases be identified?

By using testing kits or observing symptoms.

What are physical plant defences?

Tough cell walls, waxy cuticles, and bark.

What are chemical plant defences?

Antibacterial chemicals and poisons.

What are mechanical plant defences?

Thorns, hairs, or leaves that curl when touched.

Why do some plants produce poisons?

To deter herbivores.

How do plants use mimicry for defence?

Some look like other harmful plants to avoid being eaten.

What are nitrates used for in plants?

For making proteins and growth.

What happens if a plant lacks nitrates?

It suffers from stunted growth.

What are magnesium ions needed for?

Chlorophyll production.

What happens if a plant lacks magnesium?

It develops yellow leaves.

Why do plants produce antibacterial chemicals?

To kill bacteria and protect against disease.

What role do white blood cells play in the immune system?

They engulf pathogens and produce antibodies.

How do vaccines protect against disease?

They stimulate white blood cells to produce antibodies.

What is herd immunity?

When a large population is immune, reducing disease spread.

Why are viral infections harder to treat than bacterial ones?

Viruses live inside cells, making them difficult to target.

What is an example of a non-communicable disease?

Diabetes or cancer.

How does smoking increase disease risk?

It damages lungs and blood vessels.

Why is a balanced diet important?

It supports immune function and overall health.

How does excessive alcohol consumption affect health?

It can damage the liver and brain.

What are carcinogens?

Substances that cause cancer.

How does obesity increase disease risk?

It can lead to type 2 diabetes and heart disease.

What is a benign tumor?

A non-cancerous growth that doesn’t spread.

What is a malignant tumor?

A cancerous growth that can spread to other parts of the body.

How does cancer spread?

Through the bloodstream or lymphatic system.

What are risk factors for cancer?

Smoking, UV radiation, and genetics.

What is a lifestyle factor that affects disease risk?

Diet, smoking, or exercise.

How does high blood pressure increase disease risk?

It strains the heart and arteries.