GCSE AQA BIOLOGY: Monoclonal antibodies & Plant Disease

What are monoclonal antibodies?

Antibodies produced from a single group of genetically identical B-cells

What is the first step in monoclonal antibody production?

Injecting a dead or inactive form of the pathogen into a mouse

What is the second step in monoclonal antibody production?

The injection stimulates an immune response in the mice and the lymphocyte producing the complementary antibody is identified and stars producing antibodies.

What is the third step in monoclonal antibody production?

As there are only a few of the correct lymphocytes they are fused with a tumor cell to form a hybridoma which clones itself and rapidly divides allowing more antibodies to be produced.

What is the final step in monoclonal antibody production?

The antibodies are collected and purified

How do pregnancy tests work?

They contain monoclonal antibodies with dye enzymes that hCG will bind to, forming antigen-antibody complexes. The urine will move up the strip and will be trapped by another type of antibody which will create a coloured line.

What is present in the application area for a pregnancy test?

Free antibodies for hCG bound to an enzyme

What must be applied to a pregnancy test?

Urine

What happens when urine is applied to a pregnancy test?

If hCG is present, it will attach the antibodies, forming an antigen-antibody complex.

What happens as the urine moves up the stick?

It carries the enzymes attached to the monoclonal antibodies with it to the test strip

What is present at the test strip?

It contains fixed antibodies for hCG

What happens at the test strip?

The fixed antibodies attach to the antibody-antigen complex, stopping it from travelling any further

What happens when hCG is present to the test strip?

It turns blue due to colour enzyme

What happens at the control line?

Any excess antibodies bind to the control line to show that the test worked correctly and there were MABs present.

How can monoclonal antibodies be used to diagnose disease?

Same process as pregnancy tests but for cancerous cells and other pathogens.

How can specific antigens be identified in a MABs test?

attach a marker to the MABs

What are examples of MABs testing for disease?

prostate cancer and lateral flow

How can MABs measure and monitor?

They can detect the quantity of the chemical/ pathogen, for things such as performance enhancing drugs or hormones in the blood.

How can MABs be used for research?

They can be attached the fluorescent dye to detect specific molecules in a sample of tissue or blood

How can MABs be used to treat disease?

They can be binded to a toxic drug, radioactive substance or chemical which stops uncontrollable cell division in some cancers. This only targets specific cells, leading to less side effects.

Why are MABs treatments not widely used?

As they are expensive and have more side effects than expected.

What are symptoms of plant disease?

Discolouration, spots, stunted growth, decay, growths, malformation.

How can you identify plant disease?

1. reference to a gardening manual or website

2. take infected plants to laboratory to identify pathogen

3. use testing kits that contain monoclonal antibodies

What do aphids do?

Extract nutrients such as sugars from the plant, by piercing the he phloem with their mouth pieces, stunting its growth due to less respiration.

How can aphids be controlled by gardeners?

with chemical pesticides or biological control e.g ladybirds

What does a nitrate used for in plants?

combined with glucose to make amino acids for protein synthesis, chlorophyll and DNA

What are the symptoms of a nitrate deficiency?

Stunted growth, older leaves turn yellow

What is magnesium used for in plants?

making chlorophyll

What are the symptoms of chlorosis?

leaves turning yellow

How can you treat plant deficiency diseases?

timely application of fertilisers to soil

What are many plant defense responses a result of?

The fact that they are food sources for many animals, therefore evolving to prevent attacks from insects and herbivores.

What are physical defenses for?

to resist the invasion of microorganisms

What are the examples of physical plant defense responses?

Cellulose cell walls, tough waxy cuticle, tree bark, leaf fall

What does a cellulose cell wall do?

a semi permeable barrier (on the outside of the cell) supporting the cell and strengthening it