What is a cell?

The basic building block of life.

What is a tissue?

A group of similar cells working together.

What is an organ?

Different tissues working together to do a job

What is an organ system?

A group of organs working together.

What is an organism?

A whole living thing.

Put these in order from smallest to largest. tissue-cell-organ system-organism-organ

Cell → Tissue → Organ → Organ system → Organism

What is the stomach?

An organ.

What is the layer of cells lining the stomach?

A tissue.

Mouth, stomach, intestines, liver and pancreas together are what?

An organ system (digestive system).

What controls the cell?

Nucleus.

What happens in the cytoplasm?

Most chemical reactions.

What does the cell membrane do?

Controls what enters and leaves the cell.

What does the cell wall do?

Supports and strengthens the cell.

What do chloroplasts contain?

Chlorophyll.

What is the function of chloroplasts?

Photosynthesis.

What does the vacuole contain?

Cell sap

What is the function of a sperm cell?

To fertilise an egg cell.

Why does a sperm cell have a tail?

To swim to the egg.

Why does a sperm cell contain many mitochondria?

To release energy for movement.

What does the head of a sperm cell contain?

Genetic information and enzymes.

What is the function of a nerve cell?

To carry electrical impulses around the body.

Why are nerve cells long?

To carry impulses long distances quickly.

What is the function of muscle cells?

To contract and cause movement.

Why do muscle cells contain many mitochondria?

They need lots of energy.

What is the function of red blood cells?

To transport oxygen.

Why do red blood cells not have a nucleus?

More space for haemoglobin

What does haemoglobin do?

Carries oxygen.

What is the function of white blood cells?

To fight pathogens.

What is the function of platelets?

Blood clotting.

What controls the opening and closing of stomata?

Guard cells.

What is the function of stomata?

Gas exchange.

Why might plants lose water through stomata?

Water evaporates out.

Why does a cactus have a thick waxy cuticle?

Reduces water loss.

Why does a cactus have fewer stomata?

Less water can escape.

Why do cactus stomata open at night?

t is cooler so less water evaporates.

Why does a cactus have widespread roots?

To absorb water quickly.

Why does a cactus have water storage tissue?

Stores water during drought.

What chemical is used to test for protein?

Biuret solution.

Positive result for protein?

Blue → lilac/purple.

What chemical tests for starch?

Iodine solution.

Positive result for starch?

Orange-brown → blue-black.

What tests for sugar?

Benedict’s solution + heat.

Positive result for sugar?

Blue → green/yellow/orange/red.

What does blood transport?

Oxygen, carbon dioxide, nutrients, hormones and water.

Why is blood called a tissue?

It is a group of cells working together.

The process by which cells become specialised for a particular job is called _______.

differentiation/specialisation

A group of similar cells that work together is called a _______.

Tissue.

The site of gas exchange in the lungs is the ______.

Alveoli / air sac

Name the enzyme which breaks down fats.

Lipase.

The blood vessels that supply the heart muscle with its own oxygenated blood are called the ______ arteries.

Coronary arteries.

Veins carry blood away from the heart. True or False?

False.

The red pigment that carries oxygen in red blood cells is called _________.

Haemoglobin.

Which blood vessel carries blood away from the heart?

Arteries.

Which blood vessel carries blood towards the heart?

Veins.

What is the job of red blood cells?

Transport oxygen.

What is the job of white blood cells?

Fight pathogens.

Xylem cells carry water and minerals in plants. True or False?

True.

Drugs that reduce the amount of bad cholesterol in the blood are called ______.

Statins.

A disease caused by uncontrolled cell growth and division is commonly known as _____.

Cancer.

What does xylem transport?

Water and mineral ions.

Which direction does xylem transport substances?

Upwards through the plant.

What tissue transports sugar in plants?

Phloem.

What does phloem transport?

Dissolved sugars (food).

Which blood vessels carry blood away from the heart?

Arteries.

Which blood vessels carry blood towards the heart?

Veins.

What do arteries usually carry?

Oxygenated blood.

What do veins usually carry?

Deoxygenated blood.

What is the exception in the lungs?

Pulmonary artery = deoxygenated blood Pulmonary vein = oxygenated blood

What chemical tests for starch?

Iodine solution.

Positive result for starch?

Orange-brown → blue-black.

If there is no starch, what colour stays?

Orange-brown.

What chemical tests for protein?

Biuret solution.

Positive result for protein?

Blue → lilac/purple.

If there is no protein, what colour stays?

Blue.

What tests for sugar?

Benedict’s solution + heat.

Positive result for sugar?

Blue → green/yellow/orange/red.

Why must Benedict’s test be heated?

The reaction only works with heat.

Why do red blood cells have no nucleus?

More space for haemoglobin.

Why is more haemoglobin useful?

It allows more oxygen to be carried.

What does haemoglobin do?

Carries oxygen.