B4 Organising Animals and Plants

Question 1

What does blood do?

Answer 1

Carry substances around the body

Question 2

Name the 4 components of blood

Answer 2

• Red blood cells
• White blood cells
• Plasma
• Platelets

Question 3

What does plasma transport?

Answer 3

• Blood cells
• CO2 to the lungs
• Urea to the kidney
• Products of digestion from the small intestine

Question 4

Function of RBC

Answer 4

• Transport oxygen around the body

Question 5

Adaptations of RBC

Answer 5

• Biconcave shape -> increase surface area
• No nucleus -> more space for haemoglobin
• Contain haemoglobin -> bind to oxygen

Question 6

Function of WBC

Answer 6

To fight against infections and foreign pathogens

Question 7

Adaptations of WBC

Answer 7

• Phagocytes to engulf pathogens
• Lymphocytes to produce antitoxins and antibodies

Question 8

Function of Platelets

Answer 8

• Blood clotting

Question 9

Adaptations of Arteries

Answer 9

• Small lumen -> high pressure from heart pumping
• Thick layer of muscle and elastic fibre
• Thick wall

Question 10

Functions of Arteries

Answer 10

To carry blood from the heart to the rest of the body

Question 11

Adaptations of Veins

Answer 11

• Large lumen -> low pressure and no pulse
• Often have valves -> so blood flows the correct way
• Relatively thin walls -> low pressure and no pulse

Question 12

Function of Veins

Answer 12

To carry blood from the organs back to the heart

Question 13

Adaptations of Capillaries

Answer 13

• Single-cell thick walls
• Tiny vessel with a narrow lumen
• There are lots of them

Question 14

Function of Capillaries

Answer 14

To join arteries and veins through organs

Question 15

What is the double circulatory system?

Answer 15

A system where blood passes through the heart twice for every complete circuit of the body

Question 16

Advantages of the double circulatory system

Answer 16

The pressure of oxygenated blood is increased coming from the lungs before getting sent out to the rest of the body -> Oxygenates the body quicker

Question 17

What are the four chambers of the heart?

Answer 17

• Right atrium
• Right ventricle
• Left atrium
• Left ventricle

Question 18

Function of valves

Answer 18

To make sure blood goes the correct way (prevent backflow of blood)

Question 19

Function of pacemaker cells

Answer 19

Control how fast your heart beats

Question 20

Where are the pacemaker cells located

Answer 20

In the right atrium

Question 21

Why are the left muscles of the heart so thick?

Answer 21

It has to pump blood all around the body, unlike the right ventricle which only has to pump blood to the lungs

Question 22

What is the cause of coronary heart disease?

Answer 22

A build-up of fat in the pulmonary arteries leading to less oxygen getting to the heart

Question 23

How can coronary heart disease be treated?

Answer 23

• Statins -> drug to reduce cholesterol levels
• Bypass -> add extra capacity to deliver oxygen
• Stent -> open up and hold the artery

Question 24

What is the cause of arrhythmia?

Answer 24

Pacemaker cells in right atrium don’t work properly