Biology Notes of First Year
CHAPTER – 1
DEFINITION OF BIOLOGY
Biology is the study of living organisms. It is derived from Greek words.
CLASSIFICATION OF LIVING ORGANIZATION
According to the modern classification given by R.H.Whittaker in 1969, living organisms are divided into five major kingdoms, which are:
It includes all prokaryotes, unicellular organisms. For example Bacteria and Cyan bacteria.
It includes unicellular Eukaryotic organisms, which are in between plants and animals. e.g. Chlamydomonas, Euglena, Paramecium. etc
1. KINGDOM FUNGI
It includes non-chlorophyllus multi-cellular, thallophytic organisms having cell wall. For example all types of fungi, unicellular to multi-cellular like Mushrooms and Yeast etc.
2. KINGDOM PLANTAE
It includes all chlorophyllus multi-cellular Eukaryotic living organisms having cellulose cell wall. For example apple, red wood etc.
3. KINGDOM ANIMALIA
It includes all Eukaryotic multi-cellular, non-chlorophyllus organisms having no cell wall. For example Hydra, Earthworm, Human Beings etc.
Those organisms, which have true membranous structure in their cells, like mitochondria, golgi bodies, endoplasmic reticulum. e.g. All plants, Higher animals.
Those living organisms, which do not have true membranous structure in their cells. e.g. Bacteria, Blue green algae.
All living organisms of today belong to a common ancestor and each specie of organism arranged no ancestor to descendent order with rest of the group evolved from one that immediately preceded.
BRANCHES OF BIOLOGY
1. MOLECULAR BIOLOGY
It is a recent branch of biological science that deals with the structure and function of the molecules that form structure of cell and organelles that take part in the biological processes of a living organism (Nucleic acid – Protein molecule)
2. MICRO BIOLOGY
It deals with the study of...