Different branches of biology:

1. Morphology – study of external form and structure.

2. Anatomy – study of internal organs.

3. Histology – study of the details of tissue structure.

4. Cytology – study of cells.

5. Cell biology study of structure, functions and various aspects of cell and it’s components.

6. Molecular biology – study of the nature and arrangement of molecules and their interaction.

Subject studies in various branches of biology

1. Physiology – study of organ systems.

2. Embryology – study of formation of gametes, events from fertilization of egg to the development of an embryo.

3. Ecology – study of interaction of plants and animals with the environment.

4. Paleobiology – study of origin, growth and structure of organisms of past.

5. Evolution – study of continuous adaptation of plants and animals to the environment.

6. Genetics – study of Heredity and Variation.

7. Parasitology – study of parasitic organisms, ways of circulation in nature and study

the methods of struggle and liquidation of parasitic diseases of man, animals and plants.

8. Anthropology – study of origin of human and races.

II. ”Life is a method of existence of proteins. The basic point of this phenomenon is constant changes between substances and environment, but when this changes will stop, then stop life and disintegration of proteins occurs”. This definition was given by German politician Fridrich Enhels.

All living things perform certain functions or life process, which are not present in non-living things:

1. All living things have the basic structural unit of life, the cell. In unicellular organisms the single cell carries out all vital activities of life in a multicellular organism, number of cells unit together, get specialized and perform various function, to give rise to tissues, organs and organs systems.

2. Metabolism - living things need a constant supply of energy for all the activities they do. The energy is supplied by a complex series of chemical changes called metabolism.

Assimilation (latin. assimilatio – liken or likeness) is endotermical process which heed expenditure of energy. It is a process of liken (likeness) of substances that characteristic of this cell specific substances, that characteristic of this cell.

Dissimilation (latin. dissimulate - division) exotermical process of liberation of energy at the expense of disintegration of substances in cell.

Process of assimilation and dissimulation occur with participation of enzymes.

3. Growth - it is defined as an irreversible increase in weight, size or volume of an organism. The living organism can produce new parts or replace the old ones.

4. Response the stimuli: all living things give response to a change in the surroundings: The animals respond to changes in the light intensity, sound, touch, heat similarly plants also respond to sunlight, gravity, climate, length of day.

5. Reproduction - living things have the ability to produce their own kind. The resemblance of the offspring to their parents is also a characteristic features of life.

6. Homeostasis is constant structural organization.

7. Heredity is the transmission of traits from parents to offspring from one generation to next generation.

8. Variation is a change of hereditary traits and them manifestation during development of organism.

9. Adaptability - the living things undergo morphological and physiological modification to adapt themselves to the environment.

10. Evolution. All living things show the ability to change slowly over millions of years.

11. Ontogenesis is individual development of an organism.