What is biology?
Biology is the study of living organisms, which includes all plants and animals. The study of biology as a science began with Aristotle's study of plants and animals, due to which he is called the father of biology. But the term biology was first used by the French naturalist Jean Lamarck. Biology is one of the three major branches of natural science. This science is related to the study of life, life and processes of life. In this science we read about the structure, functions, development, origin, identity, distribution and classification of organisms. Modern biology is a very broad science, which has many branches. The term biology was first used by scientists named Jean-Baptiste Lamarck and Travirens in 1802 AD. The branch of science that deals with living organisms is called biology.
Characteristics of living beings:
The things which are produced as a result of a particular artificial caste process are called Jiva. They have a finite lifecycle. We are all creatures. Some fundamental processes take place in organisms:
- Organization: All organisms have a definite shape and physical and chemical organization.
- Metabolism: Animals, bacteria, fungi etc. get their diet from organic matter. Green plants take their food from the environment in the form of water, carbon-dioxide and some minerals and synthesize them through photosynthesis.
- Respiration: In this the animal transports important gases.
- Sensitivity: Sensitivity is found in organisms to external responses.
- Growth and Development: In living organisms, cell division and redistribution produce many cells, which differentiate into different parts of the body.
- Reproduction: Organisms are distinguished by their ability to raise their offspring through asexual or sexual reproduction as compared to non-living.
Classification of organisms
According to the bipedal nomenclature, each animal has two words in its name. The first term is the lineage name which is shared with its respective forms and the second term is a specific term caste designation. The combination of both the terms forms the name of the caste. In 1969 R. H. Whitaker divided the organisms into 5 kingdoms. These five worlds are as follows:-
- Monera: Organisms of this kingdom have a prokaryotic cell without nucleus. These are single-celled organisms that contain genetic material, but do not have a nucleus to separate it from the cytoplasm. Under this, bacteria and blue algae come.
- Protista: These are single celled organisms, consisting of a eukaryotic cell with a developed nucleus. Example- Amoeba, Euglena, Paramecium, Plasmodium etc.
- Fungi: These are eukaryotic cells. Because in the absence of chloroplast and pigment, photosynthesis does not take place in them. Reproduction occurs both sexually and asexually.
- Plantae: These are multicellular plants. Photosynthesis takes place in them. Vacuoles are found in their cells. Reproduction is mainly sexual. Example- Bryophyta, Lycopodophyta, Pterophyta, Psychedophyta, Conifrophyta, Anthrophyta etc.
- Animalia: These are multicellular eukaryotic organisms whose cells do not have a rigid cell wall and photosynthetic system. It is divided into two main subfamilies, Protozoa and Metazoa.
The main animal associations are:
- Protozoa: Protozoa - Animals of protozoa are very micro, unicellular (microorganism). They are also called primary animals. Protozoa is a unicellular organism. Their cells are of eukaryotic type. These can be easily seen with a simple microscope. Some protozoa cause disease in animals or humans, they are called pathogenic protozoa.
- Porifera: Their body is cylindrical. Example- Cycon, Euspongia, Spongilla.
- Coelenterata: These are the first multicellular animals with radial symmetry. They contain tissue and a digestive cavity. Example- Hydra, Jelly fish etc.
- Platyhelminthes: The body of these animals is flat, thin and soft. These are worm-like creatures. Example- Fasciola liver fluke, Schistozoma blood fluke etc.
- Aschelminth: It is a worm whose rounded body is pointed on both sides. Example- Ascaris roundworm, Oxyuris pinworm, Ancylostoma hookworm etc.
- Annelida: The round body of these worms is externally divided into rings or segments. Example- Ferretima earthworm, Hirudinerica leech etc.
- Arthropoda: The body is divided into segments which are covered from outside by a hard chitin shell. Example- Crustacean shrimp, Periplaneta cockroach, Papilio butterfly, Culex mosquito, Boothus scorpion, Lycosa wolf spider, Scolopendra centipede, Zulus millipede etc.
- Mollusca: The body of these animals is soft segmentless and does not have appendages. Example- Limex slug, Patella limpet, Loligo squid etc.
- Echinodermata: This includes animals with scaly skin. They are run by several soft tubule-like structures called umbilical cord tubules. Example- Astropactane tarmine, Acinus sea urchin etc.
- Chordata: The phylum Chordata is divided into five subfamilies-
- Hemichordate: These include pharynx, cleome, fissure and dorsal hollow nerve cord. Example- Balanoglossus Tongue Warm.
- Urochordata: These sac-like immobile organisms do not have nerve cord and dorsal cord notochord in the adult stage. Example- Herdmania, Doliolum Kanchuki etc.
- Cephalochordata: These animals have characteristic features of the chordata phylum. Example- brachiostoma amphioxus etc.
- Aignetha: It is a small group of vertebrates having suction mouth. Such creatures are called Chakramukhi Cyclostomes.
- Naithostomata: This includes fishes, amphibians, amphibians, reptiles, birds and mammals. This sub-union is divided into five sections:-
(i) Pisces: These are aquatic, amorphous, jawed vertebrates adapted to live in water throughout their life. Their bodies are covered with scales, they respire through chloems and move with the help of feathers. Example - Labeo rohu, Catla katla, Hippocampal sea horse etc. (ii) Amphibia: These are amorphous vertebrates having four legs and scaleless skin which is mostly wet. Example- Rana tigrina frog, bufo toad, salamander salamander etc. (iii) Reptilia: These asymmetric vertebrates have hard scaly skin. Example- Testudo tortoise, Henidactylus lizard, Crocodylus crocodile etc. (iv) Aves Bird class: Birds are the only organisms whose body is covered with feathers. Their forelimbs are converted into wings and are used in flight. Example: Pacer sparrow, Corvus crow, Columba pigeon, Pavo peacock etc. (v) Mammalia Mammals: These are the highest class of isothermic vertebrates. Their body is covered with hair. They have milk glands from which they feed the young ones. Example- Duck-billed platypus and spiny anteater, Felis cat, Canis dog, Panthera lion, cheetah, tiger, macaque monkey, Elephas elephant, ballina whale, Homo sapiens human etc.
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