Therefore as a single, equidimensional cell increases in size, the amount of living matter quickly outstrips the capacity of the cell to carry on such essential functions as gas exchange. If the cell becomes very flat , it can preserve a favorable surface to volume ratio, but becomes weaker and more vulnerable. Multicellularity permits organisms to develop to large size by increasing the number of similar cells thus preserving the surface to volume ratio of the cells. Name three materials of different composition commonly used by organisms to construct hard parts. For each, provide an example of a group that does so.
Opaline silica is secreted by radiolaria, diatoms, silicoflagellates, sponges, etc.
Calcium phosphate is used by brachiopods, arthropods, vertebrates, etc. 4. Give an example. The occurrence in a normal species population of two distinct stable morphologies. Rarefaction curves show that as sample size increases, the taxonomic diversity of the sample tends to increase. This is important in interpreting the history of diversity of species from the fossil record.