Flashcards
Gas Exchange in Single-Celled Organisms and Insects
Flashcards do conjunto (15)
- 1Give an example of a single-celled organism.amoeba
- 2How is oxygen absorbed in single-celled organisms?Across their body surface via diffusion, as they have a large surface area to volume ratio.
- 3What is a single-celled organisms body surface covered by?A cell-surface membrane
- 4Single-celled organisms have no barriers to the diffusion of gases, why?They have a completely permeable cell wall.
- 5What two features do insects have to reduce the amount of water lost?-Waterproof coverings
-Small surface area to volume ratio - 6Why is it hard for an insect to reduce water loss?It has spiracles that are needed for the diffusion of gases, however these open and create water loss. This needs to be controlled in order to prevent the insect becoming dehydrated.
- 7What is the pathway for diffusing gases out of an insect?Trachea --> Tracheoles --> spiracles
- 8How is the trachea given strength in insects?They are supported by rings to stop the trachea collapsing.
- 9Where do the tracheoles extend through in an insect?The tracheoles extend through all the body tissues of the insect. In this way atmospheric air, containing the oxygen, is brought directly to respiring tissues.
- 10In which two ways do respiratory gases move in and out of an insects tracheal system?-Ventilation
-Along a diffusion gradient - 11How can ventilation speed up respiratory rate in insects?The movement of muscles create mass movements of air in and out of the trachea.
- 12How do gases move in and out of insects?Spiracles
- 13How do the spiracles open and close?A valve controls the motion of them
- 14What are the limitations of an insects tracheal system?-Relies mostly on diffusion to exchange gases
-Diffusion pathway needs to be short therefore limiting the size and insect can be - 15FUN FACTInsects are one of the most successful groups of organisms on Earth :-)
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- AS Biology2 (Exchange and Transport) FlashCards sobre Gas Exchange in Single-Celled Organisms and Insects, criado por sammi_taylor01 em 29-05-2013.
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