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Reinos y Dominios © Lisa Michalek Los Reinos de la Vida • Biólogos han organizado a los seres vivos en grandes grupos llamados reinos. • Biólogos agrupar organismos en seis reinos basados en similitudes y la secuenciación de RNA y DNA: • Tipo de Celulas • Organismos son procariotas o eucariotas. – Paredes Celulares – Tipo de Cuerpo • Los organismos son unicelulares o multicelulares. – Nutricion • Organismos son autótrofos o heterótrofos. The 6 Kingdoms of Life Los 3 dominios de la vida Este árbol filogenético es basado en secuencias del rRNA que demuestran la división de todos los seres vivos en tres dominios amplia. Los 3 dominios de la vida • El dominio probablemente que el más antiguo es las bacterias, que se compone de los organismos en el Reino Eubacteria. • Archaea es el dominio de procariota segundo y también se compone de único reino Archaebacteria. • El terced dominio, Eukarya, contiene cuatro de los reinos Eucariotas: Animalia (animals), Plantae (plantas), hongos (hongos) y Protista (protistas). Las Bacterias de Dominio • Contiene un único reino, eubacterias. – Algunos científicos llaman a este reino las bacterias. • Las bacterias son procariotas y no compartimentos internos. • Las bacterias se encuentran en prácticamente todos los ambientes en la tierra. Caracteristicas de las Bacterias Las bacterias tienen fuertes muros exteriores de celular hechas de peptidoglicano, una molécula web complejo de carbohidratos filamentos reticulados por puentes de péptido corto. Tipos de Bacterias • Las bacterias pueden causar enfermedad, mientras que otros son utilizados por los seres humanos para procesar alimentos. • Las bacterias se utilizan para controlar plagas agrícolas, para producir diversos productos químicos y realizar ingeniería genética. • Algunas bacterias obtienen energía de compuestos inorgánicos como el sulfuro de hidrógeno, amoníaco y metano. • Algunas bacterias son fotosintéticas y se encuentran en el océano y los ecosistemas de agua dulce. • Algunas bacterias heterótrofas son capaces de vivir en ausencia de oxígeno. • Bacterias heterotróficas son también importantes descomponedores. El Dominio de las Arqueas • Contiene un único reino Archaebacteria. • Arqueobacterias son procariotas que se han ido muy temprano de bacterias. • Ellos están más estrechamente relacionados con eucariotas que a bacterias. Caracteristicas de Arqueobacterias • La pared celular y membrana • Las paredes celulares de las arqueobacterias no contienen peptidoglicano, como las paredes celulares de las bacterias. – Archaebacterial contienen lípidos muy diferentes a los de bacterias y eucariotas. • Estructura génica y traducción – Las proteínas ribosomales de arqueobacterias son muy similares a los de eucariotas y diferentes a los de las bacterias. Tipos de Arqueobacterias • Metanogenos – Estas arqueobacterias obtener energía mediante la combinación de hidrógeno y dióxido de carbono a metano forma. – Metanógenos viven en el fango de los pantanos y son envenenados por incluso rastros de oxígeno. • Extremofilos – Coloca a un grupo de organismos extremófilos que llaman Thermophiles vidas en muy caliente. – HalÅfilas habitan en lagos muy salados que pueden ser tres veces tan salados como el agua de mar. – Otros extremófilos viven en lugares muy ácidas o bajo una enorme presión. • Arqueobacteria no extremos – Estos crecen en todos los mismos ambientes que las bacterias. El Dominio Eukarya • Eukarya se compone de cuatro reinos: – – – – Protista Hongos Plantae Animalia • Los miembros de este dominio son eucariotas. Caracteristicas de Eukarya • Interior de la célula altamente organizada – Todos los eucariotas tienen células con un núcleo y otros compartimientos internos. • Pluricelularidad – Las actividades de las células individuales se coordinan y las células se encuentran en contacto, se produce sólo en eucariotas. • Reproduccion Sexual – División celular meiótica forma juegos haploides y dos gametos se unen para formar una célula diploide en la fertilización. – Recombinación genética durante la meiosis y la fertilización hace que la descendencia de los eucariotas a variar ampliamente, prever la evolución. Tipos de Eukarya • Una amplia variedad de eucariotas son unicelulares. – Más unicelulares eucariotas están en el Reino Protista. • Protistas contienen organismos unicelulares y multicelulares, muchos son acuáticos • Los hongos son heterótrofos que en su mayoría son multicelulares. – Muchos hongos viven y descomponen organismos muertos, otros muchos son parásitos. • Plantas y animales son todos multicellular. – Casi todas las plantas son autótrofos y han células con pared celular compuesta de celulosa. – Todos los animales son heterótrofos, compuesta por células que carecen de paredes celulares. – La mayoría de las plantas y los animales tienen tejidos y órganos. Reino y dominio características Dominio Bacterias Arqueas Eucariotas Reino Eubacterias Arqueobacterias Protista Caracteristicas Tipo de celulas Estructura celular Tipo de cuerpo Nutricion Ejemplo Procariota Pared Celular, Peptidoglicano Unicelular Autotrofos y Heterotrofos Enterobacteria Spirochetes Procariota Pared Celular, No Peptidoglicano Unicelular Autotrofos y Heterotrofos Methanogens Eucariota Mezclado Unicelular Y Multicelular Autotrofos y Heterotrofos Amoebas Euglenas Kelps Unicelular Y Multicelular Heterotrofos Yeasts Mushrooms Eucariotas Hongos Eucariota Pared Celular, Quitina Eucariotas Plantae Eucariota Pared Celular, Celulosa Multicelular Autotrofos Ferns Pine trees Eucariotas Animalia Eucariota Sin Pared Celular Multicelular Heterotrofos Birds Earthworms Multicellularity • Colonies – A colonial organism is a group of cells that are permanently associated but do not communicate with one another. • Aggregations – A temporary collection of cells that come together for a period of time and then separate. • True Multicellularity – An organism composed of many cells that are permanently associated with one another. – Enables cells to specialize in different functions. • Complex Multicellularity – Plants and animals have complex multicellularity. – The specialized cells of most plants and animals are organized into structures called tissues and organs. Kingdom Protista • Of the six kingdoms of organisms, Protista is the most diverse. • They are eukaryotes that are not fungi, plants, or animals. • Many are unicellular. • All single celled eukaryotes (except yeasts) are protists. • Some protists, such as some kinds of algae, have cell specialization. • Most are microscopic, but some are as large as trees. Kinds of Protists • Protists that use Pseudopodia – Amoebas are protists that have flexible surfaces with no cell walls or flagella. – They move by using extensions of cytoplasm called pseudopodia. – Forams have porous shells through which long, thin projections of cytoplasm can be extended. • Protists that use Flagella – Many protists move by using flagella. Kinds of Protists • Protists with Double Shells – Diatoms are photosynthetic protists with unique double shells made of silica. • Photosynthetic Algae – Distinguished by the type of chlorophyll they contain. – Many algae are multicellular and reproduce sexually. • Fungus-like Protists – Slime molds and water molds are often confused with fungi because they aggregate in times of stress to form spore-producing bodies. Kinds of Protists • Spore-Forming Protists – Sporozoans are nonmotile unicellular parasites that form spores. – Responsible for many significant diseases, including malaria, sporozoans have complex life cycles. Kingdom Fungi • Most fungi are multicellular, yeasts are unicellular. • The cell walls of all fungal cells contain chitin. • The bodies of fungi consist of long strands of cells that are connected end to end and that share cytoplasm. – The slender strands of fungi are called hyphae. – Often hyphae are packed together to form complex reproductive structures, such as mushrooms. • Fungi reproduce by a variety of asexual and sexual methods. Kingdom Fungi • Fungi do not move from place to place. • The general appearance of many fungi is similar to that of plants. – Fungi lack the green pigment chlorophyll and the ability to conduct photosynthesis. • Like animals, fungi are heterotrophs. – Fungi do not ingest their food. • Fungi obtain food by secreting digestive enzymes onto whatever they grow on. • Many fungi are saprophytes that live on dead organisms • Many other fungi are parasites that live on living organisms and cause disease that affect plants and animals. Kinds of Fungi • Zygomycetes – Form structures for sexual reproduction called zygosporangia. – Includes species such as Rhizopus stolonifer, bread mold. • Basidiomycetes – Includes fungi that make mushrooms. – Mushrooms are the sexual reproductive structures produced by basidiomycetes. • Ascomycetes – Form sexual spores in special saclike structures called asci. – The sexual reproductive structures formed often resemble a cuplike structure called an ascocarp. Kingdom Plantae • Plants are complex multicellular autotrophs. • Plants have specialized cells and tissues. • Most plants have several different types of cells that are organized into many specialized tissues. • Plants cannot move from one place to another. • Portable reproductive structures, such as spores and seeds, enable the dispersal of plants. • As autotrophs, plants are the primary producers in most terrestrial food webs. • Plants also release oxygen gas to the atmosphere. • Plants are very important in the cycling of phosphorus, water, nitrogen, and carbon. • Plants are a source of food, medicines, dyes, cloth, paper and many other products. Kinds of Plants • Nonvascular Plants – Plants without a well-developed system of vascular tissue. – These plants are relatively small. – They lack tissue to transport water and dissolved nutrients. – They also lack true roots, stems, and leaves. – Mosses are the most familiar example. • Seedless Vascular Plants – They have roots, stems, and leaves and their surfaces are coated with a waxy covering that reduces water loss. – They reproduce with spores that are resistant to drying. – Both haploid and diploid phases occupy significant parts of the life cycle. – Ferns are the most common and familiar example. Kinds of Plants • Nonflowering Seed Plants – Gymnosperms are vascular plants that reproduce using seeds but do not produce flowers. – Gymnosperms include plants that produce seeds in cones, such as pines and spruces. • Flowering Seed Plants – Most plants that produce seeds also produce flowers. – Flowering plants are called angiosperms. – Angiosperms, such as roses, grasses, and oaks, produce seeds in fruits. • Fruits are structures that enable the dispersal of seeds. • Seeds enable plants to scatter offspring and to survive long periods of harsh environmental conditions, such as drought and extreme temperatures. Kingdom Animalia • Animals are complex multicellular heterotrophs. • Their cells are mostly diploid, lack a cell wall, and are organized as tissues. • Animals are able to move rapidly in complex ways. – Movement enables animals to avoid predators and to look for food and mates. • Most animals reproduce sexually. • Almost all animals (99%) are invertebrates; they lack a backbone. • Of more than 1 million living species, only about 42,500 have a backbone; they are referred to as vertebrates. • The animal kingdom includes about 35 phyla, most of which live in the sea. Kinds of Animals • Sponges – The only animals that do not have tissues, but they do have specialized cells. • Cnidarians – Mostly marine animals; they include jellyfish, sea anemones, and corals. • Flatworms – Have flat, ribbon-like bodies. – Some are parasitic and live inside the bodies of animals. – Others are free-living and may live in soil or water. • Roundworms – Nematodes are small worms that have long, very slender bodies. – Some are free-living in soil or water, while others are parasites of animals and plants. Kinds of Animals • Segmented Worms – Annelids live in both water and soil and include the familiar earthworm. – Bristled marine worms are segmented worms, as are leeches, which can be blood-sucking parasites. • Mollusks – Have a saclike cavity called a coelom that encloses internal organs. – Are very diverse aquatic and terrestrial animals. – They include snails, oysters, clams, octopuses, and squids. – Most have a hard external skeleton (a shell). • Arthropods – The most diverse of all animals. – They have an external skeleton, jointed appendages with antennae and jaws. Kinds of Animals • Echinoderms – Includes sea stars, sea urchins, and sand dollars. – Many are able to regenerate a lost limb. • Invertebrate Chordates – Aquatic animals that have much in common with vertebrates, though they do not have a backbone. – Some are swimmers that resemble fish, while others live attached to a rock or other object. • Vertebrates – Have an internal skeleton made of bone, a vertebral column (backbone) that surrounds and protects the spinal cord, and a head with a brain contained in a body skull. – Includes mammals, fish, birds, reptiles, and amphibians.