B2- gaseous exchange systems

Question 1

what is an organelle?

Answer 1

A specialised unit within a cell which performs a specific function

Question 2

what is a cell?

Answer 2

the basic building block of all living organisms

Question 3

what is a tissue?

Answer 3

A group of cells working together to perform a shared function, and often with similar structure

Question 4

what is an organ?

Answer 4

A structure made up of groups of different tissues, working together to perform specific functions

Question 5

what is an organ system?

Answer 5

A group of organs with related functions, working together to perform certain functions within the body

Question 6

what is the exchnage surface of the human lungs adapted for?

Answer 6

• absorbing oxygen

- transporting carbon dioxide

Question 7

what is the structure of the respiratory system?

Answer 7

• The trachea, or windpipe, branches into two bronchi – one bronchus to each lung.
• Rings of cartilage in the walls of the trachea help to keep it open as air is drawn in.
• The bronchi split into smaller branches and then into smaller tubes called bronchioles.
• Each bronchiole ends in a cluster of microscopic air sacs called alveoli.

Question 8

why is exchanging of gasses in a fish so efficient?

Answer 8

the large surface area of the gills
the large surface area of the blood capillaries in each gill filament
the short distance required for diffusion – the outer layer of the gill filaments and the capillary walls are just one cell thick
the efficient ventilation of the gills with water - there is a counter current flow of water and blood