Level Biological Organization:
Biological organization is not simple. It has high degree of complexity because of which the living organisms are able to carry out a number of processes (some very complicated), which distinguish them from the non-living things. Each living being is a self-controlled structural and functional integrity. Biological organization can be divided into the following levels.
SUBATOMICAND ATOMICLEVELS:
ATOM:
All living and nonliving matter are formed of simple units called atoms which literally mean something that cannot be cut (a= without, tom = cut).
ELEMENTS:
The living substance is formed of a large number of elements. These can be classified into three groups.
Major Elements:
These elements occur in large quantities e.g. Hydrogen, carbon, nitrogen and oxygen are the major elements.
Minor Elements:
These are required in relatively small quantities e.g. Sulphur, Phosphorus etc. are minor elements.
Trace Elements:
These are required only in very small quantities or in traces. The list of trace elements is a long onc and it is still expanding. Tin, vanadium, nickel, fluorine, silicon, cobalt, copper, zinc, magnesium selenium, chromium, molybdenum, cadmium are trace elements.
MOLECULAR LEVEL MOLECULE:
In organisms elements usually do not occur in isolated forms. The atoms of different elements combine with each other through ionic or covalent bonding to produce compounds. This stable form is called a molecule. Hydrogen, carbon, oxygen, nitrogen, phosphorous and sulphur are the most common atoms found in biological molecules. Except for hydrogen, each of these atoms lacks two or more electrons to fill its outer most electron shell and can share or transfer electrons with two or more other atoms. Hydrogen can form covalent bond with one other atom, oxygen pue sulphur with two, nitrogen with three and phosphorous and carbon with up to four other atoms. The different types of bonding arrangement permit biological molecules to be. constructed in great variety and complexity. This may be micro molecules with low molecular weight like CO, H,O etc or macromolecules with large molecular weights e.g. sugars, proteins etc.
Biological world has two types of molecules.
Organic Molecule:
An organic molecule is any molecule containing both carbon and hydrogen. Some most important and abundant organic molecules in organisms are Glucose, Amino acids, Fatty acids, Glycerol, nucleotides like ATP, ADP, and AMP etc.
Inorganic molecule:
Inorganic molecule does not include carbon and hydrogen together in a molecule.
Macromolecules:
Amino acids, monosaccharides and nucleotides act as building links for the formation of high molecular weight compound i.e., Proteins, polysaccharides and nucleic acids respectively. These high molecular weight compounds are known as polymers and their building units are called monomers.
Organelles and Cell:
Starting from kingdom Monera bacteria and cyanobacteria, Protista the entire organism consists of a single cell. In most fungi, plants and animals, the organism may consist of up to trillions of cells, Numerous sub cellular structures like mitochondria. Golgi complex, Endoplasmic. reticulum, ribosomes have been studied for their structure and function. Functions of the cells are accomplished by the specialized structures compared able to the organs of the body, consequently these structure were called organelles. The arrangements of the organelles speak of the division of labor within the cell. A cell membrane is present in all cells whether prokaryote or eukaryote.
TISSUE LEVEL:
In animals and plants ,groups of similar cells are organized into loose sheets or bundles performing similar functions called a tissue. Each tissue has a particular function in the life of the organism.
Plant Tissues.
In plants, the tissues are generally divided into two types:
a) . Meristematics tissue (un differentiated).
b) . Permanent tissue (differentiated tissue).
The permanent tissue is subdivided into three types.
Living tissue:
Living tissues include epidermis and periderm.
Fundamental tissue:
The fundamental tissues are found in the interior of plant, which include parenchyma, collenchyma and sclerenchyma.
Vascular Tissue:
The vascular tissues of the plants are primarily xylem and phloem.
Animal Tissues:
In animals, tissues are of four major types.
1) .Epithelia a covering issue.
2) .Connective a connecting & supporting tissue.
3) . Nerve a conducting tissue.
4) .Muscle a contracting tissue.
ORGAN & SYSTEM:
Different tissues having related function assemble together in a structure to carry out its function with great efficiency. Such structures are called organs and they are specialized to perform particular functions. The formation of organs also has a selective value because this lead to an efficient accomplishment of their functions, both qualitatively and quantitatively. Animal Organs In animals organ formation is far more complex and defined. In animals organs are part of organ systems where total functions involved in one process or phenomenon are carried out. The complexity of the organ systems of animal is associated with a far greater range of functions and activities than is found in plants.
Plant Organs:
The level of organization in much less definite in plants then it is in animals. At most , we might distinguish roots , stems , levels and reproductive structures.
INDIVIDUAL (WHOLE ORGANISM):
Various organs in plants and various organ systems in animals are assembled together to form an individual the whole organism. The whole organism has its individuality as far as its characteristics are concerned. It is different form other of the same species in certain respects. The various functions, processes, activities of an organism are coordinated. In animals the coordination is achieved by means of nervous system and endocrine system whereas, in plants, only hormones bring about long-term regulation of activities. Organism works as a whole and it interact and responds to the environmental changes as a whole.
POPULATION:
Population is higher levels of biological organization than organism (whole) because here a group of organism of the same species are involved. This level of organization has its own attributes, which come into being by living of a group of organism of the same species together.
COMMUNITY:
The collection of interacting organisms within an ecosystem is called a community. A community consists of many kinds of organisms. One of the ways that organisms interact is by feeding one another. Different organisms belong to the different trophic levels i.e., producer and consumer (herbivores, carnivores). A community includes many different food chains. Some organism may be involved in several of the food chains at the same time, so that food chain become interwoven into a food web. By looking at the foregoing account it is clear that an organism can be studied at different levels of organization.
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