Homozygous and Heterozygous: An individual that carries two identical alleles for a locus is said to be homozygous for that locus. if the two alleles are different, then the individual is said to be heterozygous (e.g. Aa).
The gene which occur maximum in nature in an individual is called the ‘wild type‘. while the alteration in the genetic material produces ‘mutant type‘ gene. The alleles, which are significant in both homozygous and heterozygous conditions, are known as the dominant alleles. For example, in Tt and TT, the tallness is the dominant trait. The alleles, which are significant in homozygous condition, are called the recessive alleles. The individuals possessing the alleles ‘tt’ exhibit dwarfness.
Phenotype and Genotype: Phenotypes result front the expression of the genes of an organism as well as the influence of environmental factors, while the genetic makeup of an individual is referred to the genotype of that organism. The phenotype includes physical characteristics, behaviors corresponding to such species, structures, organs, behaviors, reflexes, etc. and those traits that can be observed through the eyes. Geno type refers to the genetic traits in an organism. It has to do with the genetic coding of an organism. Such coding is inheritable. The geno-type is the genetic load that is copied every time a cell divides, and therefore is inherited down to the next generation. Geno-type is something we can’t see with our eyes (e.g. dominant, recessive, heterozygous). In other words, the geno-type is the genetic programming that provides the phenotype.