Volume and surface areas of organisms Flashcards
what is the volume and surface area of organisims
Thesurface area-to-volume ratiorefers to thesurface areaof an organism in relationto itsvolume. The diagram below will help explain this concept.
how does the surface area and volume change when a cell divides
The surface-area-to-volume ratio decreases as a cell or organismincreases
in size.
If the cell becomes too big in a single cell, the cell membrane will not have sufficient surface area to support the rate of diffusion required for the increased volume.In other words,as a cellgrows,it becomesless efficient. The same concept applies to organisms.
As an organism grows larger, it requires more complex structures to keep it functioning optimally.The solution to the problem of growing too large is to develop more specialised systems that will perform specific tasks. These adaptations led to the development of more sophisticated animal phyla.
Larger animals require more specialised tissue, organs and organ-systems to remain efficient within their environment.Smaller organisms can use their body’s surface area to bring gases into the body (e.g. Porifera, Cnidaria, Platyhelminthes and Annelida).
what are some ways that invertebrates can be useful to ecosystems
- Invertebrates as pollinators.
- Invertebrates as decomposers.
- Invertebrates that aerate the soil.
why are invertebrates as pollinators important
Many flowering plants depend on invertebrates, especially insects, for pollination. If pollination did not happen, no seeds would form. If there were no seeds, all flowering plants worldwide would disappear. Pollination is also important in agriculture.
why are invertebrates as decomposers important
When plants and animals die, different kinds of bacteria, fungi andinvertebratesdecompose the dead bodies that are made of organic compounds. When organic matter is decomposed, it forms simple nutrients. Therefore, thedecompositionof organic compounds is necessary because itreturns simple nutrientsto the soilto be used by the next generation of plants and then animals. If the dead remains of organisms were not decomposed, the world would quickly run out of nutrients and all ecosystems would stop working.
Many invertebrates play an essential part as decomposers in ecosystems. For example, the free-living worms of thePlatyhelminthesandAnnelidsare mostly animals thatfeed on dead and decaying organic matter. They change organic matter into humus, which is the first stage of recycling nutrients.
why are invertebrates which aerate the soil important
Wheninvertebratessuch as earthworms move through the soil, theyaerateit. Their burrows let in air and make it easier for water on the surface of the soil todrain. If water drains quickly into the soil, the run-off of water on the surface that causes soil erosion is reduced.
