AQA GCSE Infection and Response

What is the name for an organism that causes a disease?

What is the name for an organism that causes a disease?

Pathogen

What 4 types of pathogen are there?

Bacteria

Virus

Fungi

Protist

How can disease be spread in animals and plants?

Direct contact

Water

Air

What do bacteria and viruses do once inside the body?

Reproduce rapidly

What do bacteria release to make us feel ill?

Toxins

How do viruses make us feel ill?

Reproduce inside cells

How do we protect against measles?

Vaccination

What initial symptoms does HIV cause?

Flu-like symptoms

What do we use to control the reproduction of HIV?

Antiretroviral drugs

Tobacco Mosaic Virus is a disease that affects plants. What are the symptoms?

Mosaic pattern on leaves which reduces photosynthesis, stunting growth

How is tobacco mosaic virus spread from plant to plant?

Direct contact

What type of pathogen causes salmonella and gonorrhoea.

Bacteria

What type of cell is a bacterial cell?

Prokaryotic

Where is DNA found in a prokaryotic cell

In the cytoplasm

How is salmonella spread?

Through contaminated food

How do we treat gonorrhoea?

Antibiotics

What type of pathogen causes rose black spot and athlete's foot?

Fungi

Rose black spot is a disease affecting plants. What are the symptoms?

Spots on leaves. Then leaves turn yellow and drop off

Why do plants with rose black spot disease grow more slowly?

They can't photosynthesise as much

How is rose black spot spread?

Through water and wind

How is athlete's foot spread?

Direct contact

How can we treat rose black spot?

Remove affected leaves and use fungicides

What pathogen causes malaria?

Protists

What organism transports the protist pathogen between hosts and acts as a vector?

Mosquitoes

What is the term for an organism that spreads disease without directly causing it?

A vector

How does the skin protect us from infection?

Forms a physical barrier

What does the stomach have to protect us from infection?

Stomach acid

What three things do white blood cells do to respond to pathogens?

Release anti-toxins

Release antibodies

Phagocytosis (engulf pathogens)

What is the process during which white blood cells engulf and break down pathogens using digestive enzymes?

Phagocytosis

What is the name of the chemical released by white blood cells to neutralise toxins released by bacteria?

Anti-toxins

What type of substance are antibodies and enzymes?

Proteins

What is special about the binding site of an antibody and the antigens on the pathogen they are produced against?

Complementary shape

What is the name for the process of introducing small quantities of dead or inactive forms of a pathogen into the body to stimulate white blood cells to produce antibodies?

Vaccination

If the same pathogen enter again then white blood cells respond quickly to produce antibodies much faster, preventing infection. What is this known as?

Immunity

What do we call medicines that help to cure bacterial disease by killing infective bacteria inside the body?

Antibiotics

Why can antibiotics not be used to treat viruses?

Viruses reproduce inside our cells

How have antibiotics affected death rates from infectious disease?

Greatly reduced them

What do we call a strain of a bacteria that isn't affected by a particular antibiotic?

Resistant

What type of drug treats symptoms but does not kill pathogens?

Pain killers

How did we first get drugs?

From plants

Where does the heart drug, digitalis come from?

Foxgloves

Where can we get the painkiller aspirin?

Willow

Who discovered penicillin?

Alexander Fleming

How do we make drugs now?

Using chemicals in labs

During drug trials, what do we test drugs for?

Toxicity

Efficacy

Dose

What is meant by toxicity of a drug?

Whether or not it harms body cells

What is meant by efficacy of a drug?

How effectively a drug kills pathogens

What is meant by the dose of a drug?

How much of a drug is needed to be effective

What are drugs tested on during preclinical trials?

Cells

Tissues

Live animals

Who is involved in clinical trials?

Healthy volunteers and patients

Why are healthy volunteers used in clinical trials?

As controls

What sort of dose is used in the first stage of a clinical trial to see if the drug is safe?

Low dose

If a drug is found to be safe at during initial clinical trials, what happens next?

More trials to work out dosage

What do we call "fake" drug, often a sugar pill taken during a drugs trial to see if improvements are psychological?

A placebo

Who knows who has taken the drug or the placebo during a blind clinical trial?

Scientists and doctors

Who knows who has taken the drug or the placebo during a double blind clinical trial?

Only the scientists

Which type of clinical trial would you use to ensure that no researcher bias can happen where patients or researchers try to find results that aren't there?

Double blind trial