Circulation System Flashcards Preview

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Flashcards in Circulation System Deck (14)
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1
Q

Why do large multicellular organisms need a circulation system?

A

to transport substances around their bodies

2
Q

why do small organisms not need a circulation system?

A

they can rely on diffusion because they have a large sa:v and the diffusion distance is small

3
Q

what substances are circulated round the body in animals?

A
o2 
co2 
urea 
glucose
amino acids 
salts 
hormones 

most of these are dissolved in water

4
Q

what is mass transport?

A

moving substances in large quantities over long distances in one direction.

5
Q

Mass flow -

A

Liquids can be forced around a circulatory system by a pump. The pump generates pressure and the liquid moves from areas of high pressure to lower pressure.

6
Q

single circulation system -

A

blood passes through the heart once during each cycle.

7
Q

Double circulatory system -

A

Blood passes through the heart twice in one complete circuit of the body e.g. in a human

8
Q

circuit of the double circulation system -

A

heart to lungs to heart to body to heart

9
Q

what properties make water good for transport ?

A
  • liquid from 0 to 100
  • good solvent
  • high specific heat capacity
  • ice is less dense than liquid water
10
Q

what is a dipole water molecule?

A

Water molecules have a slight negative charge at the oxygen end and a slight positive charge at the hydrogen end. Hydrogen bonds form between water molecules causing it to become a liquid.

11
Q

what is water a good solvent of?

A

ionic, charged and polar substances

12
Q

why is water a good solvent of ionic, charged and polar substances?

A

Due to attraction between particles in the chemicals and the polar water molecules.

13
Q

what substances do not dissolve in water?

A

non polar substances

14
Q

give an example of a non polar substance

A

lipids