Cute Baby Animal Pictures Biography
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and independently. All animals are also heterotrophs, meaning they must ingest other organisms or their products for sustenance.Most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago.Etymology
The word "animal" comes from the Latin word animalis, meaning "having breath".[1] In everyday colloquial usage, the word often refers to non-human members of kingdom Animalia. Sometimes, only closer relatives of humans such as mammals and other vertebrates are meant in colloquial use.[2] The biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects and humans.[3]
Characteristics
Animals have several characteristics that set them apart from other living things. Animals are eukaryotic and multicellular,[4] which separates them from bacteria and most protists. They are heterotrophic,[5] generally digesting food in an internal chamber, which separates them from plants and algae.[6] They are also distinguished from plants, algae, and fungi by lacking rigid cell walls.[7] All animals are motile,[8] if only at certain life stages. In most animals, embryos pass through a blastula stage,[9] which is a characteristic exclusive to animals.
Structure
With a few exceptions, most notably the sponges (Phylum Porifera) and Placozoa, animals have bodies differentiated into separate tissues. These include muscles, which are able to contract and control locomotion, and nerve tissues, which send and process signals. Typically, there is also an internal digestive chamber, with one or two openings.[10] Animals with this sort of organization are called metazoans, or eumetazoans when the former is used for animals in general.[11]
All animals have eukaryotic cells, surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins.[12] This may be calcified to form structures like shells, bones, and spicules.[13] During development, it forms a relatively flexible framework[14] upon which cells can move about and be reorganized, making complex structures possible. In contrast, other multicellular organisms, like plants and fungi, have cells held in place by cell walls, and so develop by progressive growth.[10] Also, unique to animal cells are the following intercellular junctions: tight junctions, gap junctions, and desmosomes.[15]All animals are heterotrophs, meaning that they feed directly or indirectly on other living things.[27] They are often further subdivided into groups such as carnivores, herbivores, omnivores, and parasites.[28]
Predation is a biological interaction where a predator (a heterotroph that is hunting) feeds on its prey (the organism that is attacked).[29] Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of the prey.[30] The other main category of consumption is detritivory, the consumption of dead organic matter.[31] It can at times be difficult to separate the two feeding behaviours, for example, where parasitic species prey on a host organism and then lay their eggs on it for their offspring to feed on its decaying corpse. Selective pressures imposed on one another has led to an evolutionary arms race between prey and predator, resulting in various antipredator adaptations.[32]
Most animals indirectly use the energy of sunlight by eating plants or plant-eating animals. Most plants use light to convert inorganic molecules in their environment into carbohydrates, fats, proteins and other biomolecules, characteristically containing reduced carbon in the form of carbon-hydrogen bonds. Starting with carbon dioxide (CO2) and water (H2O), photosynthesis converts the energy of sunlight into chemical energy in the form of simple sugars (e.g., glucose), with the release of molecular oxygen. These sugars are then used as the building blocks for plant growth, including the production of other biomolecules.[10] When an animal eats plants (or eats other animals which have eaten plants), the reduced carbon compounds in the food become a source of energy and building materials for the animal.[33] They are either used directly to help the animal grow, or broken down, releasing stored solar energy, and giving the animal the energy required for motion.[34][35]
Animals living close to hydrothermal vents and cold seeps on the ocean floor are not dependent on the energy of sunlight. Instead chemosynthetic archaea and bacteria form the base of the food chain.
This is a discussion on The definition of cute - Puppy howling within the General Dog Discussion forums, part of the Keeping and Caring for Dogs category; Don't know if this has been posted already.For the 1920s there’s Juliette, the imagined companion of Coco Chanel resplendent in pearls and a tweed jacket; the 1940s envisages a pug called Sydney dressed in a tuxedo complete with bow tie as Charlie Chaplin’s ideal pooch, and 1990 sees Fernandez the dog wearing a polo neck jumper as the companion of the late Steve Jobs. However they are classified, it is accepted that the NGSD is the most primitive "domestic" dog, brought to the island by humans at least 6,000 years ago. Kept pure due to isolation from other types of dogs until the 1950s, they are like a living fossil. Almost all of the NGSD in North America have descended from the original Taronga Zoo pair. Offspring of this founder pair were widely distributed to zoos in America and Europe.In this sense, 2013 got off to a good start in Europe and the United States. On January 1, a European Union directive came into effect banning the use of individual sow stalls from the fourth week of pregnancy until one week before the sow gives birth. Millions of sows must now have the elementary freedom not only to turn around, but to walk. Nor can they be kept on bare concrete without straw or some other material that allows them to satisfy their natural instinct to root. By the end of January, 20 of the 27 EU member states were at least 90% compliant with the directive, and the European Commission was preparing to take action to ensure full compliance.
CommentsView/Create comment on this paragraphMeanwhile, in America, active campaigning by the Humane Society of the US has led to about 50 major pork buyers announcing that they will phase out their purchase of pork from suppliers who use sow stalls. (Some, including Chipotle and Whole Foods, already have.)
CommentsView/Create comment on this paragraphStill, Europe is far ahead of the US on farm-animal welfare. The ban on sow stalls there continues the progress made to ameliorate the most extreme forms of animal confinement.
CommentsView/Create comment on this paragraphIndividual stalls for veal calves were the first to go, in 2007. Last year, the standard battery cage for egg-laying hens was banned, ensuring somewhat better conditions for hundreds of millions of hens (though they can still be kept in cages that severely restrict their movement).
CommentsView/Create comment on this paragraphThe new standards are compromises that are premised on the assumption that Europeans will continue to eat animal products and do not wish to see a sharp rise in the cost of their food. Predictably, therefore, animal-welfare advocates are not – and should not be – satisfied, even if, as the European Commission’s scientific and veterinary advice indicates, the new standards will reduce animal suffering.
CommentsView/Create comment on this paragraphAnother European directive came into effect on January 1, banning medical research on chimpanzees. It went unnoticed, because there has been no European medical research on chimpanzees since 2003. During the past 20 years, other countries have also stopped using chimpanzees for medical research; indeed, only the US and Gabon continue to do so, with the US by far the larger user.
CommentsView/Create comment on this paragraphLast month, the National Institutes of Health, the US government agency responsible for biomedical research, approved a report recommending the cancelation of the majority of NIH-funded projects involving invasive biomedical research on chimpanzees. The report also recommends that most of the chimpanzees owned or supported by the NIH should be “retired” from research and moved to sanctuaries.
CommentsView/Create comment on this paragraphThe NIH will retain only one colony, comprising roughly 50 chimps, and any research carried out on these apes will have to be approved by an independent committee that will include public representation. The report also recommends special requirements for keeping the remaining chimps: housing in groups of at least seven, with a minimum of 1,000 square feet per chimp, room to climb, and opportunities to forage for food. The NIH action still needs to be ratified by the director, Francis Collins.
CommentsView/Create comment on this paragraphWith billions of animals still leading miserable lives on factory farms, more space for pregnant sows and the release from labs of a few hundred chimpanzees may not seem like much to cheer about. But the larger picture is worth celebrating. For centuries, humans in industrialized countries have treated animals as units of production, rather than as sentient beings with a moral status that requires us to take their interests into account. (In more traditional societies, relations between humans and animals have often been closer, but not always better for the animals.)
CommentsView/Create comment on this paragraphThe struggle to liberate animals from oppression is a moral campaign comparable to the struggle to end human slavery. Indeed, the enslavement of animals, for labor and for food, is more pervasive and more central to our way of life than the enslavement of other humans ever was. With some isolated and short-lived exceptions – for example, in India under the Emperor Ashoka and in Japan under the Tokugawa shogun Tsunayoshi – laws to protect animals from cruelty are less than 200 years old.
CommentsView/Create comment on this paragraphIt is therefore bound to be a long struggle. But, if the gains made so far seem to be dwarfed by the wrongs that humans continue to do to animals, we can find hope in the fact that, as January’s developments show, the pace of change is accelerating perceptibly
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