Flashcards
Exchange Between Organisms and Their Environment
Flashcards do conjunto (9)
- 1Give four examples of things that need to be interchanged between an organism and its environment.-respiratory gases
-heat
-excretory products
-nutrients - 2What two different ways can this exchange occur in (include examples as well)-actively, e.g. active transport which goes against a concentration gradient
-passively, e.g. diffusion or osmosis which goes down a concentration gradient. - 3What two factors affect the amount of each material that needs to be exchanged?-size of an organism
-metabolic rate of an organism - 4What increases the efficiency of how much a substance is exchanged?surface area to volume ratio
- 5Give some examples of features of specialised exchange surfaces.-large surface area to volume ratio
-thin diffusion pathway
-partially permeable membrane
-movement of internal/environmental mediums to maintain a gradient. - 6Give the equation for working out diffusion.surface are X difference in concentration
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length of diffusion path - 7What is a disadvantage of a thin diffusion pathway and how do we overcome it?They are easily damaged, therefore they are often located inside an organism for protection.
- 8What is the surface area to volume ratio like for: 1) small organisms 2) large organisms1) large surface area to volume ratio
2) small surface area to volume ratio - 9For organisms with a large surface area to volume ratio, organisms have evolved to have the two following features which help overcome the problem:-a flattened shape so no cell is far from the surface
-specialised exchange surfaces with a large surface area (e.g. gills in fish, lungs in mammals)
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- AS Biology2 (Exchange and Transport) FlashCards sobre Exchange Between Organisms and Their Environment, criado por sammi_taylor01 em 29-05-2013.
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- sammi_taylor01
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