Organisation in animals

Question 1

What are tissues

Answer 1

A group of similar cells that work together to carry out a particular function

Question 2

What is an organ

Answer 2

A group of different tissues that work together to perform a particular function

Question 3

What is an organ system

Answer 3

A group of organs working together to perform a particular function

Question 4

What is the function of the circulatory system

Answer 4

To get food and oxygen to every cell in the body.

Question 5

Name the 4 chambers of the heart

Answer 5

Right atrium, right ventricle, left atrium, left ventricle

Question 6

Name the main blood vessels leading into and out of the heart

Answer 6

Vena cava, pulmonary artery, pulmonary vain, aorta

Question 7

Define aorta

Answer 7

An artery which transports blood from the heart to the rest of the body

Question 8

define vena cava

Answer 8

A vein which transports blood into the heart from the rest of the body.

Question 9

define pulmonary artery

Answer 9

An artery which transports blood out of the heart to the lungs

Question 10

define pulmonary vein

Answer 10

A vein which transports blood into the heart from the lungs

Question 11

What are arteries

Answer 11

Arteries are blood vessels which carry blood away from the heart, towards the organs.

Question 12

Artery adaptations

Answer 12

• Strong elastic walls
• thick layers of muscle and elastic fibres allow them to stretch
• Thick walls and a narrow lumen

Question 13

What is the function of capillaries

Answer 13

supply food and oxygen to the cells and take away waste products like carbon dioxide

Question 14

Capillary adaptations

Answer 14

• Permeable walls so substances being exchanged can diffuse in and out.
• Walls are one cell thick to reduce diffusion distance
• Very narrow to give them a large surface area to volume ratio. Also increases the rate of diffusion.

Question 15

What is the role of a vein

Answer 15

To carry blood to the heart

Question 16

Vein Adaptations

Answer 16

• Thinner walls as there is less blood pressure.
• Bigger lumen to help blood flow

Question 17

Rate of blood flow equation

Answer 17

rate of blood flow = volume of blood/ number of minutes

Question 18

What is the job of a red blood cell

Answer 18

to transport oxygen around the body

Question 19

Red blood cell adaptations

Answer 19

• They have a biconcave shape to give them a large surface area to absorb oxygen.
• They contain red pigment called HAEMOGLOBIN, which carries oxygen.
• No nucleus which allows more room for haemoglobin, so they can carry more oxygen.

Question 20

Role of white blood cells

Answer 20

To defend against microorganisms that cause disease.

Question 21

How do white blood cells prevent disease

Answer 21

• They engulf foreign microorganisms and digest them.
• They can produce antibodies to fight microorganisms.
• They can produce antitoxins to neutralise any toxins produced by microorganisms.

Question 22

What are platelets

Answer 22

Small fragments of cells that have no nucleus. They help the blood to clot at a wound.

Question 23

What are 3 things that plasma carries

Answer 23

• Red and white blood cells and platelets.

-Urea from the liver to kidneys.

• Antibodies and antitoxins produced by the white blood cells.