b1-5 flashcards full

What are the main parts of an animal cell?

Nucleus, cytoplasm, cell membrane, mitochondria, and ribosomes.

What is the function of the nucleus?

Controls cell activities and contains genetic material (DNA).

What is the function of the cell membrane?

Controls movement of substances into and out of the cell.

What is the function of the cytoplasm?

Where most chemical reactions take place.

What is the function of mitochondria?

Site of aerobic respiration.

What is the function of ribosomes?

Protein synthesis.

What extra parts do plant cells have?

Cell wall, chloroplasts, and permanent vacuole.

What is the function of the cell wall?

Strengthens and supports the cell.

What is the function of chloroplasts?

Site of photosynthesis.

What is the function of the permanent vacuole?

Contains cell sap and helps keep the cell turgid.

How are bacterial cells different from animal and plant cells?

They are smaller, have no nucleus, contain circular DNA, and may contain plasmids.

What is a specialised cell?

A cell adapted to carry out a specific function.

How is a sperm cell adapted to its function?

Tail for movement, many mitochondria for energy, and an acrosome containing enzymes.

How is a nerve cell adapted to its function?

Long axon to carry electrical impulses and branched connections.

How is a muscle cell adapted to its function?

Contains protein fibres and many mitochondria.

How is a root hair cell adapted to its function?

Large surface area for absorption of water and minerals.

What is differentiation?

The process by which a cell becomes specialised.

What are chromosomes?

Structures made of DNA that carry genes.

What is mitosis?

Cell division that produces two genetically identical daughter cells.

Why is mitosis important?

Growth, repair, and asexual reproduction.

What is a stem cell?

An unspecialised cell that can develop into different cell types.

Where are adult stem cells found?

Bone marrow.

What are meristems?

Regions in plants containing stem cells.

What is diffusion?

Movement of particles from a region of high concentration to low concentration.

What factors affect diffusion?

Concentration gradient, temperature, surface area, and diffusion distance.

What is osmosis?

Movement of water through a partially permeable membrane from a dilute solution to a concentrated solution.

What is active transport?

Movement of substances against the concentration gradient using energy from respiration.

What is the organisational hierarchy in living organisms?

Cells → Tissues → Organs → Organ Systems → Organisms.

What is a tissue?

A group of similar cells working together.

What is an organ?

A structure made of different tissues working together.

What is an organ system?

A group of organs working together.

What is the function of amylase?

Breaks down starch into sugars.

What is the function of protease?

Breaks down proteins into amino acids.

What is the function of lipase?

Breaks down lipids into fatty acids and glycerol.

What is bile?

A substance made in the liver that neutralises stomach acid and emulsifies fats.

What are the three types of blood vessels?

Arteries, veins, and capillaries.

What is the function of arteries?

Carry blood away from the heart.

What is the function of veins?

Carry blood back to the heart.

What is the function of capillaries?

Allow exchange of substances between blood and cells.

What is the function of red blood cells?

Transport oxygen.

What is the function of white blood cells?

Defend against pathogens.

What is the function of platelets?

Help blood clot.

What is plasma?

The liquid part of blood that transports substances.

What is coronary heart disease?

A disease caused by fatty deposits in coronary arteries.

What is health?

A state of physical and mental wellbeing.

What is a benign tumour?

A non-cancerous tumour that does not spread.

What is a malignant tumour?

A cancerous tumour that can spread.

What is the function of xylem tissue?

Transports water and mineral ions through a plant.

What is the function of phloem tissue?

Transports dissolved sugars around a plant.

What is transpiration?

The loss of water vapour from plant leaves.

What factors affect transpiration?

Light intensity, temperature, humidity, and wind speed.

What is a pathogen?

A microorganism that causes disease.

What are the four types of pathogen?

Viruses, bacteria, fungi, and protists.

What is measles?

A viral disease spread by droplets from coughs and sneezes.

What are symptoms of measles?

Fever and red skin rash.

What is HIV?

A virus that attacks the immune system and can lead to AIDS.

How is HIV transmitted?

Sexual contact, blood transfer, and shared needles.

What is tobacco mosaic virus (TMV)?

A plant virus that damages chloroplasts and reduces photosynthesis.

What causes salmonella food poisoning?

Bacteria in contaminated food.

What are symptoms of salmonella?

Fever, stomach cramps, vomiting, and diarrhoea.

What causes gonorrhoea?

A bacterium spread by sexual contact.

What are symptoms of gonorrhoea?

Pain when urinating and thick yellow or green discharge.

What is rose black spot?

A fungal disease affecting rose plants.

What is malaria?

A disease caused by a protist and spread by mosquitoes.

What are the body's natural defences?

Skin, mucus, cilia, and stomach acid.

How do white blood cells defend the body?

By phagocytosis, producing antibodies, and producing antitoxins.

What is vaccination?

Introducing dead or inactive pathogens to stimulate an immune response.

What is herd immunity?

Protection of a population when a high proportion are vaccinated.

What are antibiotics?

Medicines that kill bacteria.

Why do antibiotics not work against viruses?

Viruses reproduce inside body cells and are difficult to target without damaging cells.

What is antibiotic resistance?

When bacteria evolve and survive antibiotic treatment.

What are painkillers?

Drugs that reduce symptoms but do not kill pathogens.

Who discovered penicillin?

Alexander Fleming.

What is a placebo?

A dummy treatment with no active ingredient.

What is a double-blind trial?

A trial where neither the patient nor the doctor knows who receives the real treatment.