diversity in living organisms class 9
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Fishare very diverse and are categorized in many ways. This article is an overview of some of the more common types of fish. Although most fishspecies have probably been discovered and described, about 250 new ones are still discovered every year. According to FishBase, 31,500 species of fish had been described by January 2010. That is more than the combined total of all other vertebrates: mammals, amphibians, reptiles and birds.
Fish systematics is the formal description and organisation of fish taxa into systems. It is complex and still evolving. Controversies over "arcane, but important, details of classification are still quietly raging."
The term "fish" describes any non-tetrapodchordate, (i.e., an animal with a backbone), that has gills throughout life and has limbs, if any, in the shape of fins. Unlike groupings such as birds or mammals, fish are not a single clade but a paraphyletic collection of taxa, including jawless, cartilaginous and skeletal types.
Jawless fish are the most primitive fish. There is current debate over whether these are really fish at all. They have no jaw, no scales, no paired fins, and no bony skeleton. Their skin is smooth and soft to the touch, and they are very flexible. Instead of a jaw, they possess an oral sucker. They use this to fasten on to other fish, and then use their rasp-like teeth to grind through their host's skin into the viscera. Jawless fish inhabit both fresh and salt water environments. Some are anadromous, moving between both fresh and salt water habitats.
Extant jawless fish are either lamprey or hagfish. Juvenile lamprey feed by sucking up mud containing micro-organisms and organic debris. The lamprey has well developed eyes, while the hagfish has only primitive eyespots. The hagfish coats itself and carcasses it finds with noxious slime to deter predators, and periodically ties itself into a knot to scrape the slime off. It is the only invertebrate fish and the only animal which has a skull but no vertebral column. It has four hearts, two brains, and a paddle-like tail.
Cartilaginous fish have a cartilaginous skeleton. However, their ancestors were bony animals, and were the first fish to develop paired fins. Cartilaginous fish don't have swim bladders. Their skin is covered in denticles, that are as rough as sandpaper. Because cartilaginous fish do not have bone marrow, the spleen and special tissue around the gonads produces red blood cells. Some cartilaginous fishes possess an organ called Leydig's Organ which also produces red blood cells.
Bony fish include the lobe finned fish and the ray finned fish. The lobe finned fish is the class of fleshy finned fishes, consisting of lungfish, and coelacanths. They are bony fish with fleshy, lobed paired fins, which are joined to the body by a single bone. These fins evolved into the legs of the first tetrapod land vertebrates, amphibians. Ray finned fishes are so-called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines ("rays").
There are three types of ray finned fishes: the chondrosteans, holosteans, and teleosts. The chondrosteans and holosteans are primitive fishes sharing a mixture of characteristics of teleosts and sharks. In comparison with the other chondrosteans, the holosteans are closer to the teleosts and further from sharks.
Teleosts are the most advanced or "modern" fishes. They are overwhelmingly the dominant class of fishes (or for that matter, vertebrates) with nearly 30,000 species, covering about 96 percent of all extant fish species. They are ubiquitous throughout fresh water and marine environments from the deep sea to the highest mountain streams. Included are ne
The largest organism found on Earth can be measured using a variety of methods. It could be defined as the largest by volume, mass, height or length. Some organism s group together to form a superorganism, though this cannot truly be classed as one large organism. (The Great Barrier Reef, the
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Answers:I. Nonvascular Plants: a. Mosses require _______moisture______________ for growth and reproduction. b. They look pretty lowly and insignificant, but have become dominant in particular habitats and Sphagnum itself is said to occupy ______1___% of the earth's surface. c. Because of its ability to soak up blood and its relative freedom from bacterial contamination ____Sphagnum _____ was used in wound dressings II. Existing Seedless Vascular Plants "Amphibians of the Plant Kingdom" a. If we could have wandered about on earth in the Devonian period the only conspicuous land plants would have been something like the _______whisk fern__________, Psilotum. It has virtually no ______leaves__________ and no _______roots_________. b. The phyla _______Lycopodiophyta____________ includes Lycopodium and Selaginella. Lycopodium species can be found in Ohio, and throughout the world - in a wide range of habitats but usually growing beneath other plants. c. The phyla __________Equisetum_________ is represented today by one genus, ______Equisetaceae__________ the horsetails or scouring rushes. These are widely distributed, usually growing in marshes and waterlogged soil. The plant is essentially _____shooted/noded______, it has a rhizome which puts out adventitious roots. d. The phyla ______Pteridophyta_________ is the second largest division of the plant kingdom. There are ________55_________ species of ferns compared to about 250,000 flowering plants alive today. III. The Rise of the Seed-Bearing Plants: a. Unlike the seedless vascular plants, ____________________ are more prevalent in cooler regions and in __________ habitats. Because of their leaf and stem anatomy they are better adapted to ______________ than most broadleaved trees. b. ________________ or similar plants were the food of herbivorous ________________ and the fate of both of these groups of organisms was probably closely linked. They survive as a few species of tropical palm-like trees, including one which is native to the USA, Zamia pumila the cardboard palm. c. This is a _________________division, a single species of a single genus, _______________ the maidenhair tree. d. There are a few living plants which are intermediate between conifers and angiosperms - members of the __________________such as Wellwitschia mirabilis IV. AngiospermsFlowering, Seed-Bearing Plants (260,000 species) a. ___________________ means "seed in a vessel." The vessel arose by the folding or fusion of sporophylls. b. ______________________ have one cotyledon, Flower parts often in threes, never truly woody. c. ______________________ have two cotyledons, Flower parts often 4, 5 or many, can be woody or herbaceous. d. The family _________________ lies within the class of dicotyledonae and in the division of anthophytha. There are about 100 known genera and almost 700 species in this family. It is know to many as the gourd or pumpkin family. e. This family includes food crops, turf, and important industrial crops. _______________ is the most important family of food crops, including the cereals, wheat Triticum, corn Zea and rice (Oryza). f. Plants in the ____________________ or mint family are annual or perennial herbs but some are shrubs, small trees, or vines. The flowers have 5 fused petals that will diverge into 2 lips (bilabiate)
Answers:well u can become a paleantologist....and classify fossils...... u can become a naturalist and search for new species on this planet and classify and /or modify the current classification system. microbiologists are finding newer strains of bacteria viruses protists etc. which need to b classified.
Answers:I didn't realize there were 9 characteristics of living things, but here's what I can name off the top of my head: 1. Organization 2. Homeostasis 3. Reproduction 4. Growth 5. Development 6. Transformation of energy and matter 7. Respond to stimuli 8. Adapt to environment One or more of these may be redundant.
Answers:It really is a lot to ask for some of these, below are some condensed pointers for some. 1. They try to show evolutionary relationships (phylogeny) rather than just randomly group them on how they look or what effect they give. 2. By using a dead leanguage everyone knows what you are talking about without the language changing or being influenced by local names. eg. Green Plover, Peewit, Lapwing are all the same bird Vanellus vanellus. 3. Allowed a natural or phylogenetic ordering system to be attempted. 4. Shared characters. At the "lowest" level Genus and species they share many similarities and are closely related. Higher up they share more "general things" and are distantly related. 5. So everyone knows what the original naming of a species related to. 6. No relationship to relatedness, look up analogous and homologous. 7. See 6. 8. No, obvious if you have understood 1-7. 9. Often unrooted. 10. Nice and easy to look up, see 6. 11. Because real life is not defined by hard edges 12. New techniques, especially molecular. 13. Coping with the data from 12.