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Gas Exchange and circulatory systems

Most gas exchange surfaces have two common areas:

They have a large surface area
They're thin (one cell thick) Thus a
short diffusion pathway
The organism also maintains a steep
concentration gradient of gases across
the exchange surface

These factors.. Increase the rate of diffusion…

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Have tiny air filled pipes call tracheae to exchange gas.
Air moves into the tracheae via pores on the surface called
O2 then travels down the concentration gradient to the cells.
CO2 from the cells moves down its own gradient to the spiracles
to be released into the atmosphere.…

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Circulatory system - Fish

Due to a lower concentration
of oxygen in water than air,
fish needed to adapt;
1) Water enters through the mouth and out through the gills

2) Each gill's made of numerous thin gill filaments to give a big surface area for gas

3) The…

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Dicotyledonous plants

Exchange gases at the surface of mesophyll cells. Plants need CO2 for
photosynthesis and give O2 as waste. They use O2 for respiration giving CO2
as waste.

The main area for exchanging these is the surface of the mesophyll cells in
the leaf. They're well adapted for their…

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Control of water

Plants and insects have adaptations to minimise water loss during gas exchange.

If insects lose too much water, they close their spiracles using muscles. The plants
have a waterproof, waxy cuticle on the body with tiny hairs by the spiracles to
reduce evaporation.

Plants' stomata usually stay…

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The lungs
The body needs a constant supply of oxygen for the process of respiration.
The gas carbon dioxide is produced as a waste product.

The lungs are found in the part of the body called the thorax and this is
separated from our digestive organs by the diaphragm. The…

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colourless solution that turns cloudy when carbon dioxide is added


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