Showing posts with label Biology. Show all posts
Showing posts with label Biology. Show all posts

Jul 18, 2012

Plant Communities

The assemblage of plants in a habitat is called plant communities. The communities are not the random mixture of species. Each community consists of a set of many different species, which persists year after year. In a community, each plant species is represented by innumerable individuals. A group of individual of the same species is commonly known as population. Thus a population is a part of community and population of different species may be intermingled in a community. Henry J. Oosten defines communities as an aggregation of living organism, having mutual relationship among them and to the environment. The following points characterized the community.

Jul 17, 2012

The Nitrogen Cycle

Plant absorb greatest quality of nitrogen from the soil for the synthesis of amino acid, protein, enzymes, nucleic acid, chlorophyll, etc. the main source of nitrogen compound is the atmospheric nitrogen. Nitrogen cycle consists of the following steps:

Nitrogen fixation: Conversion of atmospheric nitrogen into free nitrogen is referred as nitrogen fixation. This process is of two types a)Non-biological nitrogen fixation and b) Biological nitrogen fixation

About The Carbon Cycle

Carbon is the basic constituents of all organic compounds. The source of carbon found in the living organism is atmospheric carbon dioxide (CO2), which is found in Free State in atmosphere and in dissolved state in water. Green plants are autotrophic, which use carbon dioxide through photosynthesis in the presence of sun light and carbohydrate is formed. When herbivorous animal consume the green plants, the carbon compound contained in the plant will be turned into other carbonic compound. 

Jul 8, 2012

Economic Importance of Fungi

Fungi have both positive ad negative roles in our daily life. So they are our friends as well as foes (enemy).
They are described as below.
Beneficial Roles or Useful Activities.
i)    Fungi are used as food. e.g. Mushrooms and Morels.
ii)    Fungi are used in laboratory.
      a) Baking Yeast (S. cerevisae)
      b) Several alcoholic beverages such as wine, whiskey, beer, rum all are prepared by fermentation activity of sugar solution by wine yeast. (S. ellipsoidens)      c) Some fungi are used in production of enzymes like amylase, pectimase
iii)  Some fungi are used in production of several antibiotics and antibiotics and other useful medicine like penicillin, streptomycin, ergotine and ephedrine respectively.

Economic Importance of Bacteria

Bacteria play very important role in the continuous sustenance of life. They are man’s best friends as well as enemy. There are many useful as well as harmful bacteria around us. Economic importances of bacteria are studied under two headings they are Beneficial activities and Harmful activities. Beneficial Activities are studied under three headings
A)    Agricultural Importance
i)    Dead and decay of organic matter-saprophytic bacteria eg. Clostridium, Staphylo, Coccus, salmonella etc acts upon the organic matter and disintegrates them converting valuable fertilizer.
ii)    Nitrification:- It is a process of conversion of organic substance into nitrate form which are utilized by green plants easily. Eg Nitrifying bacteria like ammonia salts (nitrosomes and nitrococcus) to nitrites (nitrobacter) – Nitrates

Jun 7, 2012

Cell Biology, Conceptual Questions with Answers

1. What is cell?
Cell is the basic structural and functional unit of living organism. It is the smallest unit, that can carry all the process of life.

2. Who discovered the cell?
In 1665 Robert Hooke studied the cell in a thin slice of cork for the first time.

3. Who gave the cell theory?
Schleiden and Schwann gave a cell theory which proposes that the bodies of animals and plants are composed of cells and products of cells.

4. How cell arise?
According to cell theory all cells arise from pre-existing cells.

May 25, 2012

Introduction To Biology

1. Why water is important for our life?
Water is a major chemical of protoplasm which plays a major role in our life.

2. What do you mean by carbohydrate?
Carbohydrates are the organic compounds of carbon, hydrogen and oxygen, where the hydrogen and oxygen are present in the ration 2:1 as in water.

3. Give the name of different types of carbohydrates.
Carbohydrates are classified into monosaccharides, disaccharides and polysaccharides.

Jan 24, 2012

Introduction to Biology

Why calcium is an important life component?
Calcium forms exoskeleton of invertebrates, imparts strength and rigidity to bones and teeth and the middle lamella of plant cell wall consist of calcium pectate. For these function, calcium is considered as an important life component.

What are important life components?
The important life components are basically classified into two types:
1.    Inorganic compounds: Water and Minerals.
2.    Organic compounds: Carbohydrates, lipids, proteins and nucleic acids.

Dec 14, 2011

Acid Rain and Greenhouse Effect

What is Acid Rain? How is it Caused?

Generally, acid rain means the rain of water containing excessive amount of acids.
Oxides of Slulphur, Carbon, and Nitrogen are major gaseous pollutant of air. These oxides are produced mainly by the combustion of fossil fuels, power plants, automobile exhaust, domestic fire etc. These oxides make layers and remains in the atmosphere. During rain, they react with water to form acids like Sulphuric acid, Nitric acid, Nitrous acid which then comes to the earth surface as acid rain or remain in the atmosphere in clouds or fogs.