B6

What is biodiversity?

The variety of different species of organisms in an ecosystem or on Earth.

Why does high biodiversity contribute to ecosystem stability?

Because species are less dependent on each other for food and shelter.

What is a quadrat?

A tool to sample the distribution and abundance of organisms in a defined area.

What is a transect used for?

To estimate organism distribution across an area, such as a field.

What is percentage cover in sampling?

An estimation method that is subjective and less accurate than counting.

What is a pooter?

A small jar with tubes used to collect insects via suction.

How does a pitfall trap work?

Catches insects that fall into a buried container, preventing escape.

What is the capture-recapture method?

Marking and releasing organisms, then resampling to estimate population size.

List 4 negative human impacts on ecosystems.

Land use, hunting, pollution, deforestation.

List 2 positive human impacts on ecosystems.

Habitat preservation, breeding programmes.

What is food security?

The ability to provide enough food for the population.

Why does meat consumption affect food security?

It’s less energy efficient and takes up more space than crops.

What is hydroponics?

Growing plants in a mineral solution without soil.

What is selective breeding?

Choosing parents with desired traits and breeding over generations.

Give one advantage of selective breeding.

Improved yield and quality of food.

Give one disadvantage of selective breeding.

Reduced gene pool and increased vulnerability to disease.

What is genetic engineering?

Altering an organism’s genome to introduce desirable traits.

What is Golden Rice?

A GM rice that produces vitamin A from beta-carotene.

What is the difference between communicable and non-communicable diseases?

Communicable are infectious; non-communicable are not.

How does HIV increase TB risk?

Weakened immune system makes one more susceptible to TB.

What is Tobacco Mosaic Virus (TMV)?

A virus that infects plant chloroplasts, causing white patches and reducing photosynthesis.

What causes athlete’s foot?

A fungal infection spread by contact with infected surfaces.

How is malaria transmitted?

By female Anopheles mosquitoes, which act as vectors.

What is phagocytosis?

White blood cells engulf and digest pathogens.

What do antibodies do?

Bind to antigens, clump pathogens, and help destroy them.

What are monoclonal antibodies?

Identical antibodies produced from a single lymphocyte.

What hormone do pregnancy tests detect?

hCG (human chorionic gonadotropin).

How do vaccines work?

By introducing dead/inactive pathogens to stimulate immunity.

What causes antibiotic resistance?

Mutation and survival of bacteria not killed by antibiotics.

Why can’t antibiotics treat viruses?

Viruses replicate inside body cells, making them hard to target.

What is a zone of inhibition?

An area around an antibiotic where bacteria do not grow.

List the 3 stages of drug development.

Preclinical trials, animal testing, human clinical trials.

List 3 risk factors for cardiovascular disease.

Smoking, high salt intake, saturated fat.

What are statins used for?

Lowering blood cholesterol.

What are stents used for?

Keeping coronary arteries open.

What is metastasis in cancer?

The spread of cancer cells to other parts of the body.

List one benefit and one risk of stem cell therapy.

Benefit: replace damaged cells. Risk: mutations/ethical issues.

What is the Human Genome Project?

A project to map human DNA and predict disease risk and treatment outcomes.