HEREDITY-Transmission of features or characters from one generation to another or from parents to offspring through their genes.

VARIATION-It occurs due to sexual reproduction,inaccuracies during DNA replication(mutation)and due to environmental factors.

GENETICS-Branch of biology dealing with the study of heredity and variations.

ALLELES-They are modified from of a gene. eg a gene T (TT)represent the height.Modified from of it is "t"(tt).

GREGOR JOHANN MENDEL(1822-1884)-He is known as 'Father of Genetics'.He worked on sweet pea plant(Pisum sativum).

GENOTYPE-Genetic composition of individual.

PHENOTYPE-Visible traits of an individual.

EVOLUTION-Gradual changes in traits of organisms from preexisting organisms is called evolution.

SPECIATION-It may take place when variation is combined with geographical isolation.