Organisation Biology GCSE

Question 1

Name the four components of the blood

Answer 1

White blood cells, plasma, platelets and red blood cells

Question 2

Write the function of each of the four components of the blood (4 marks)

Answer 2

red blood cells- transport oxygen throughout the body
white blood cells- fight against infection (send off antitoxins to kill microorganisms)
platelets- responsible for scab clotting
plasma- the liquid part of the blood, containing essentially everything (acids, glycerol etc), that are sent around the body

Question 3

Name the three blood vessels

Answer 3

Veins, arteries, capillaries

Question 4

List the order of the organisation hierarchy (smallest to biggest)

Answer 4

Cell, tissue, organ, organ system, organism

Question 5

List the different components of the digestive system, in the order at the which they are used in the process of digestion

Answer 5

The mouth, salivary glands, oesophagus, liver, gall bladder, duodenum, stomach, pancreas, large intestine, small intestine, rectum, anus

Question 6

What are enzymes? (1 mark)

Answer 6

Enzymes are biological catalysts (from protein) that speed up chemical reactions without getting used up.

Question 7

List the three types of enzymes, along with an example of that type of enzyme, and the food group they act on.

Answer 7

Carbohydrases (example = amylase) > carbohydrates
Proteases (example = pepsin) > proteins
Lipases (example = lipase) > fats (lipids)

Question 8

List the substance produced from each type of enzyme, and where they are located in the body.

Answer 8

1. carbohydrases = glucose, simple sugars. These are found in the pancreas, salivary glands and the small intestine
2. proteases = amino acids. These are found in the stomach, small intestine and the salivary glands
3. lipases = fatty acids/glycerol. These are found in the pancreas and the small intestine.

Question 9

Describe how enzymes break down substances (6 marks)

Answer 9

Model Answer:
The enzyme collides with the substrate. The substrate then binds to the active sight of the enzyme to form the enzyme-substrate complex. The substrate then breaks down into two new products. The substrate will only fit the active sight of this enzyme and this unique fit or connection is known as the ‘lock and key theory’. This idea is the same idea behind a certain key fitting a certain lock.

Question 10

Explain the function of veins

Answer 10

> Veins carry blood from the rest of the body back to the heart (low in oxygen and a purple-red colour)

Question 11

How do valves work? Where are they needed and why?

Answer 11

Valves open as the blood starts to flow through them and closes when they begin flowing backwards. These are located in veins due to low blood pressure: the blood is now a great distance from the pump of the heart.

Question 12

Explain the function of arteries

Answer 12

Arteries carry blood from the heart to the rest of the body, therefore containing oxygenated blood.

Question 13

How are arteries adapted for carrying out their function?

Answer 13

Having thick muscular walls, allows them to withstand the very high pressure of the blood.
> Elastic fibres strech when the surge of the blood passes through and then recoil in between surges, keeping the blood moving.

Question 14

How are veins adapted for carrying out their function?

Answer 14

They have much thinner walls than arteries; the blood pressure is low so they don’t need to be thick
> have valves to prevent backflow from the blood
> wide diameter

Question 15

Explain the function of capillaries.

Answer 15

These are a huge network of tiny vessels that link the arteries and veins. Substances such as glucose and oxygen diffuse from the blood to the cells, and vice versa (with CO2)

Question 16

How are capillaries adapted for carrying out their function?

Answer 16

They have very thin walls and are narrow, making the diffusion path very short (aids diffusion rate)

Question 17

Name all the components of the respiratory system.

Answer 17

Mouth, Trachea, Nasal Cavity, Bronchioles, Bronchi, Lung, Alveoli, Diaphragm

Question 18

Describe the term diffusion (1 mark)

Answer 18

Diffusion is the movement of gases from an area of high concentration to an area of lower concentration

Question 19

Give three features of alveoli that allow large amounts of oxygen to enter the blood (3 marks)

Answer 19

1. Thin walls (one cell thick)- short diffusion path
2. Large quantities of alveoli drastically increase the surface area of the lungs
3. They are moist, enabling the blood to diffuse into the alveoli and then into the bloodstream efficiently