Seres vivos VMT

Verónica Brunasso - Magdalena di Lorenzo - Tatiana Zaldivar

Seres vivos

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Living Things

Classification of Plants & Animals

At any one time in history, there are millions of different kinds of plants and animals in the world. In 1753, a scientist in Sweden named Carolus Linnaeus thought of an orderly system for classifying plants and animals. He grouped all organisms according to a two-part name (binomial). The first part of the name is the "generic" grouping orgenus. The second part is the "specific" grouping or species. Scientists today still use this basic idea of his system, but modern classifications systems are much more complicated having many levels of hierarchical organization. For example, taxonomicsystems group organisms according to structure and physiological connections between organisms. Phylogenic systems classify based on genetic connections. Evolutiontheories have impacted modern classification.

In order to begin to classify plants, consider the structure by which the plant absorbs water. Plants are either vascular or non-vascular. Vascular plants have tube-like structures that transport water from the roots to the stem to the leaves. Non-vascular plants absorb water only through their surfaces.

Use common vegetables to observe the vascular structure and nature of plants.

Another way to consider plant classification is according to reproduction. Some plants reproduce by producing seeds. Others produce spores. To begin to classify animals, consider the backbone. Animals that have a backbone are called vertebrates. Animals that do not have a backbone are called invertebrates. All invertebrates lack backbones, but their other physical characteristics are quite varied. They must be, considering that 95 percent of all animals are invertebrates. Some, like worms, have soft bodies with no bones at all. Some other invertebrates, like snails, have soft bodies, but carry a hard shell for protection. These soft-bodied invertebrates that live in water or on land are grouped asmollusks. Besides snails, some other mollusks are clams, mussels, and squid. Some other invertebrates have tough coatings on the outside of their bodies (exoskeletons), jointed legs, and a segmented body. This group is known as thearthropods. Insects, spiders (arachnids), centipedes/millipedes, and shrimp, lobster, and crabs (crustaceans) are all arthropods. There are more insects (over 900,000 species) than any other group of arthropods. There are more arthropods than any other group of invertebrates. And, considering that 95 percent of all animals are invertebrates, that makes arthropods truly the must abundant group. One particularly popular member of the insect world is the butterfly. This arthropod, with its tough outer shell, characteristic wings, and antennae, belongs to the insect family.

All vertebrates have a backbone. Their other physical characteristics are quite varied. One way to consider groups of vertebrates is according to their diet. Animals that primarily eat plants are known as herbivores. Animals that feed mostly on meat are known as carnivores. Some animals, called omnivores, eat both plants and meat. An animal's eating habits are influenced by its anatomy. Meat-eaters have jaws and teeth designed for tearing and crushing. The canine teeth are enlarged and the molars have sharp cusps. The intestinal tract is adapted for handling quick digestion of meat. Plant-eaters usually have large incisors for cropping and cutting plants. Their large, ridged molars are adapted for grinding tough plant fibers and their intestines are rather long, allowing for slow digestion of plant fibers. Another way to consider groups of vertebrates is according to their body temperature. All vertebrates are either cold-blooded or warm-blooded. A vertebrate is considered cold-blooded if its internal body temperature matches the external temperature around it. Fish, amphibians and reptiles are examples of cold-blooded animals. Their dependence on the water or land makes it necessary for them to adapt to the temperature surrounding them. Warm-blooded animals are able to control their body temperature. No matter what the temperature is outside, their internal body temperature remains the same. Only birdsand mammals are warm-blooded. Birds rely upon their feathers to help adapt to temperature changes. Mammals rely upon skin, hair, or fur to help adapt to temperature changes. Another characteristic of all mammals is the ability of the female to produce milk to feed her babies. Some mammals, like whales, live in the water and must adapt to changing water temperatures. Other land mammals, like wolves, have adapted to very cold climates. In general, however, warm-blooded animals must prepare for temperature extremes in order to survive. Predicción de conceptos Diálogo con el escritor sobre los conceptos Ser vivo: organismo constituido por células. Cumple con funciones: desarrollo, reproducción, adaptación, nutrición. Ser no vivo: aquel ser que no cumpla alguna función de los seres vivos. Animales: organismos vertebrados. Especie: grupo de organismos. Mamíferos: animales que presentan pelos y glándulas mamarias. Aves: animales que poseen picos y alas aunque no todas las utilizan para volar. Tienen el cuerpo cubierto por plumas. Reptiles: animales que tienen escamas. Peces: animales acuáticos, la mayoría con escamas, aletas y branquias. Autótrofo: organismos que sintetizan sustancias pudiendo nutrirse a sí mismo. Heterótrofo: organismos que deben alimentarse con sustancias orgánicas sintetizadas por otros organismos. Clasificación de plantas: - Vasculares: tienen estructuras que transportan agua desde las raíces al tallo hasta las hojas. - No vasculares: absorben el agua solo a través de sus superficies. Según la reproducción: - producción de semillas. - producen esporas. Clasificación de animales: - Vertebrados: tienen columna vertebral: - de acuerdo a su dieta: hervíboros, carnívoros, omnívoros. - de acuerdo a su temperatura corporal: de sangre fría: peces, reptiles y anfibios; de sangre caliente: aves y mamíferos: - Invertebrados: no tienen columna vertebral: - moluscos: de cuerpo blando viven en el agua o en tierra (caracol, almejas, mejillones, calamares). - antrópodos: de recubrimientos duros en el exterior, patas articuladas y cuerpo segmentado (insectos, arañas, cangrejos). Teniendo en cuenta los conceptos expuestos en el cuadro anterior podrás realizar el siguiente crucigrama: REFERENCIAS 1- Plantas que poseen estructuras tubulares que transportan agua desde las raíces hasta las hojas. 2- Animales que dependen de las plumas para adaptarse a los cambios de temperatura. 3- Animales que poseen columna vertebral. 4- Animales que poseen mandíbulas y dientes diseñadas para desgarrar y triturar. Generalmente se alimentan de carne. 5- Animales que poseen pelos y capacidad de producir leche. 6- Animales que comen plantas y carne. 7- Animales invertebrados de cuerpo blando que viven en el agua o en tierra. Por ejemplo caracoles, almejas, mejillones, calamares.