i need help with homework!!-producers

[kiekyon]

This is a somewhat controversial question because biological classification is always changing as our knowledge increases. For hundreds of years all organisms were put into two kingdoms, the Animal Kingdom and the Plant Kingdom. In that system, algae, plants, fungi and bacteria were all in the Plant Kingdom. Nowadays, most botany textbooks have switched to a five kingdom system: Animalia, Plantae, Fungi, Protista or Protoctista (algae and misc. organisms) and Monera (bacteria). Some botanists place the algae in the Plantae rather than in the Protista. The Protista is sort of the kingdom for all the organisms that don't fit well in the other four kingdoms so some scientists think the Protista should be divided into even more kingdoms.

Therefore, algae can be considered plants or nonplants depending on which kingdom you decide to put them in.

[AstusAleator]

I have no doubt in my mind that algae are protista. If you look at the similarities between things like euglenas and volvox or red kelp... They're very similar. Yes, algae can form more complex structures via communal cooperation, but they're still just single-celled protista. This point is emphasized if you study their life-cycles.

Someone earlier said that photosynthetic organisms are plants, algae, and cyanobacteria. I would change that to plants, (some) protista, and cyanobacteria, as there are photosynthetic protista (euglena) that are not algae.

[Numurose]

yes, i think so... :)

[MrMistery]

first of all, there are other bacteria except cyanobacteria. Second, algae are considered plants by physiologists. Third, some algae like Macrocystis and Sargassum deffinetly show that they are multicellular. Heck, they even have lateral meristems. Forth, by some classifications, euglena is Euglenophyta and it is a type of green algae

[mkwaje]

See this is the problem of taxonomists, our classification system are relative... that is... classifications will always be based on which character we deem more important than others. Time changes and different people will say, "Oh this characteristic will better classify these set of organisms" and afte a while another will say differently. Consequently, we will not expect to fit all the organisms in our little scheme of things... we are only humans after all. Currently, classification using 16s rRNA homology is said to be a good classification system. That's why some the formerly one group of Monera became Eubacteria and Archaebacteria.

So I would say that in our school, algae is classified under Kingdom Protista but who knows in other schools, it may be classified differently; I wouldn't say they are wrong though. Maybe we all are. Who really knows?

[morine]

dear,
there are two producers in an ecological cycle.we have the the primary and secondary producers,this then improves that producers are those plants that manufacture their food an example of this are plants that manufacture their food from sunlight and manufacture their food by photosynthesis