Animal organisation - gaseous exchange systems - AQA Flashcards
(12 cards)
Name the level of organisation in order
In order of increasing complexity, multicellular organisms are made of:
cells → tissues → organs → organ systems
What is an organelle
A specialised unit within a cell which performs a specific function
What is a cell
The basic building block of all living organisms
What is a tissue
A group of cells working together to perform a shared function, and often with similar structure
What is an Organ
A structure made up of groups of different tissues, working together to perform specific functions
What is an Organ
A group of organs with related functions, working together to perform certain functions within the body
The effectiveness of exchange surfaces in plants and animals is increased by having
A large surface area, A short distance required for diffusion:
A large surface area has?
The flattened shape of structures such as leaves
the alveoli in the respiratory system
the villi in the digestive system
A short distance required for diffusion has ?
the membranes of cells
the flattened shape of structures such as leaves
the walls of blood
capillaries are one cell thick
the epithelia of alveoli in the respiratory system and the villi in the small intestine are only one cell thick
An efficient blood supply to transport molecules to and from the exchange surface increases effective exchange. Examples of this include:
the network of blood capillaries that surrounds each alveolus in the lungs
the network of blood capillaries in each villus in the small intestine
The human lungs provide an
exchange surface
adapted for:
absorbing
oxygen
– needed for respiration – into the blood from the air
transferring
carbon dioxide
– produced by respiration – from the blood into the lungs then the air
