Most animals and plants consist of different types of cells organised as tissues, organs and systems. The human respiratory system is a body system adapted for efficient gas exchange.
What is an organelle?
A sub-cellular structure
A group of tissues
Why do large, multicellular organisms need a transport system?
The surface area to volume ratio of their bodies becomes too large
Concentration gradients between areas of the body are too large
Distances are too large to move substances by diffusion
Which adaptation in plants contributes to the efficient exchange of gases?
They are able to ventilate their leaves
The flattened shape of a leaf
Low concentration gradients between the outside and inside of the leaf
Which one of the following is an adaptation to improving the efficiency of gaseous exchange?
Clusters of alveoli in the lungs increase the efficiency of gaseous exchange
The presence of rings of cartilage in the trachea
The fattened, globular shape of plants such as cacti
Which one of the following processes leads to air being breathed into human lungs?
Contraction of the diaphragm
An increase in air pressure in the lungs
Relaxation of the external intercostal muscles
In the respiratory system, which structure connects a bronchus to an alveolus?
How are blood capillaries well-adapted for gaseous exchange?
There are always very high concentration gradients across capillaries
Their walls are just one cell thick
The blood in them is under high pressure
Which one of the following is NOT a tissue?
Why is obtaining oxygen more difficult for a fish than a land animal?
Its system for gas exchange is very inefficient
The oxygen concentration of water is much lower than air
They have a poor gas exchange surfaces
Through which structure does oxygen-deficient water leave the body of a fish?
Through the mouth
Through the operculum
Through the gills