3.GENETICS: Branch of biology dealing with the study of heredity and variations.
4.ALLELES :There is one pair of alleles which can express itself whether present in homozygous
state or heterozygous state. Eg – T (tallness in pea plant), R(round seeds in pea
5.GREGOR JOHANN MENDEL:- (1822-1884): He is known as the father of ‘genetics’. He
worked on Sweet pea plant(pisum sativum).
6.GENOTYPE: genetic composition of an individual, eg – pure tall-TT, hybrid tall-Tt
7.PHENOTYPE: Visible traits of an individual. Eg – Tallness or Dwarfness.
8.EVOLUTION: gradual changes in traits of organisms from pre existing organisms is called
9.SPECIATION: It may take place when variation is combined with geographical isolation.