B4 Organisation in animals

Question 1

What is a tissue?

Answer 1

A group of cells with similar structures and functions

Question 2

Name the five levels of organisation

Answer 2

cells
tissues
organs
organ system
organism

Question 3

What is an organ?

Answer 3

A group of tissues working together to perform a specific function

Question 4

What is the function of the liver in digestion?

Answer 4

Produces bile

Question 5

What is the function of bile in digestion?

Answer 5

Neutralises hydrochloric acid;
emulsifies fat to form small fat droplets which increases the surface area (for lipase enzymes)

Question 6

What is the function of saliva in digestion?

Answer 6

Lubrication to help swallowing;
contains amylase to break down starch

Question 7

Name three enzymes produced by the pancreas

Answer 7

amylase
protease
lipase

Question 8

Name the four main components of blood

Answer 8

red blood cells
white blood cells
plasma
platelets

Question 9

What is the function of platelets?

Answer 9

form blood clots which:
1. prevents the loss of blood
2. Stops wounds getting infected

Question 10

Describe three adaptations of a red blood cell

Answer 10

1. biconcave shape - large surface area to volume ratio for diffusion of oxygen
2. contains haemoglobin - binds to oxygen
3. no nucleus - more space for haemoglobin so therefore more oxygen

Question 11

Name the substances transported in the blood plasma

Answer 11

hormones
proteins
urea
carbon dioxide
glucose

Question 12

Why is the human circulatory system a double circulatory system?

Answer 12

Blood passes through the heart twice for every circuit through the body
Deoxygenated blood is pumped from the right side of the heart to the lungs
Oxygenated blood that returns to the left side of the heart is pumped from the left side to the rest of the body

Question 13

How does the structure of the artery relate to its function?

Answer 13

Function - carries blood away from the heart under high pressure
Structure - has a small lumen and thick elasticated walls that can stretch

Question 14

How does the structure of a vein relate to its function?

Answer 14

Function - carries blood back to the heart under a low pressure;
Structure - doesn’t need thick elasticated walls but has valves to prevent blood flowing the wrong way

Question 15

How does the structure of a capillary relate to its function?

Answer 15

Function - Carries blood to the cells and tissues
Structure - has a one cell thick wall to provide a short diffusion distance

Question 16

List the structures air passes through when breathing in

Answer 16

mouth/nose
trachea
bronchi
bronchioles
alveoli