|
Created by siobhan.quirk
over 11 years ago
|
|
ProkaryotesOrganisms which belong to the kingdom Prokaryota (used to be called Monera). These organisms include the bacteria and the cyanobacteria (used to be called blue-green algae). Prokaryote means 'before nucleus'. The main feature of all the prokaryotes is given in their name - they evolved before the nucleus became the place to keep the DNA. So all prokaryotes have no nucleus. The prokaryotes: have no nucleus have a loop of naked DNA (DNA that is not associated with histore proteins) that is not arranged in linear chromosomes. have no membrane bounded organelles have smaller ribosomes than in other groups carry out respiration not in mitochondria, but on special membrane systems (mesosomes) have cells smaller than those of eukaryotes may be free-living or parasitic; some cause diseases ProtocistsAll members of the kingdom Protocista are eukaryotes. This group contains organisms that are single-celled. It also contains some multicellular organisms, e.g. algae.The smaller memners of this kingdom used to be known as protocists. The protocists: are eukaryotes are mostly single celled show a wide variety of forms show various plant-like or animal-like features are mostly free-living have autotrophic or heterotropic nutrition - some photosynthesise, some ingest prey, some feed using extracellular enzymes (fungi) amd some are parasites. They do not qualify to belong in any of the other kingdoms.FungiThe members of the kingdom Fungi are a group of organisms in which the body consists of a mycelium - a network of numerous strands called hyphae. The cytoplasm is surrounded by a wall of a polysaccharide called chitin. The cytoplasm is usually not divided into cells. It has many nuceli. A few fungi are cellular. The fungi: are eukaryotes have a mycelium, which consists of hyphae have walls made of chitin have cytoplasm that is multinucleate are mostly free-living and saprophytic - this means that they cause decay of organic matter PlantsThe green plants are all multicellular organisms. They gain their nutrition from photosynthesis. This means that they are autotrophs. The plants: are eukaryotes are multicellular have cells surrounded by a cellulose cell wall produce multicellular embryos from fertilised eggs have autotrophic nutrition AnimalsThe animals are multicellular organisms that gain their nutrition by digesting and absorbing organic matter - they are heterotrophic. The animals: are eukaryotes are multicellular have heterotrophic nutrition have fertilised eggs that develop into a ball of cells called a blastula are usually able to move around
New Page
Want to create your own Notes for free with GoConqr? Learn more.