Unit 3- Exchange organs and mass transport systems Flashcards
Can substances in single celled organisms diffuse directly into/out of the cell surface membrane?
Yes
Why is the diffusion rate quick in single celled organisms?
Small distance the substances have to travel (short diffusion distance)
Why is diffusion across the outer membrane too slow in multicellular organisms?
Some cells are deep within the body- large distance between them and the outside environment
Larger animals have a low SA:V ratio- it is difficult to exchangeWhat is enough substances
What is mass transport?
An efficient system to carry substances too and from their individual cells
Give an example of an exchange organ
The lungs
Give an example of a mass transport system
The circulatory system
Which 3 things affect heat exchange?
Body size
Body shape
Adaptions for heat exchange
Does a small surface area loose heat less quickly?
Yes
Why do smaller organisms need a relatively high metabolic rate?
To generate enough heat to stay warm
Do animals with a large SA:V ratio loose heat more quickly?
Yes
Animals with a high SA:V ratio tend to lose more water as it evaporates from their surface what adaption do small animals have for this?
-Have kidney structure adaptions so that they produce less urine to compensate
