Introduction:
1. The term genetic was coined by William Bateson in 1960.
2. Father of classical genetics is Mendel.
3. Father of modern genetics is Bateson.
4. Father of Experimental genetics/ Drosophila genetics is Morgan.
Some basics concepts and definitions:
1. Genetics: Genetics is the branch of biology which deals with study of heredity and variation.
2. Heredity: Heredity is also called Inheritance. It is involve transmission of character/passing of traits from parent to there offsprings.
3. Variation: It means the differences [Morphological, physiological, to logical and behavioristic] among the individuals of the species and offspring of the same parents.
4. Trait: It is a phenotypic characters of an organism.
Example: Eye colour is a character of offspring's.
5. Gene: It is a region of DNA which encode function.
6. Chromosomes: It consist of long strand of DNA.(Condensed form of DNA)
Example: Humen chromosome can have upto 500 million base pair (mpb) of DNA and 1000 of gene.
7.Alleles: It is also called allelomorph. It is different form of genes. 1 of 2 more possible form of gene that are found at the same place of chromosomes.
Alleles / endomorph indicate alternative form the same genes.
Example: Tall = TT , Drawf = tt
Alleles obtain from Greek word = Allelo = Mutual or reciprocal. Each new organism inherit 2-Alleles from its parent 1 form egg (OVA) and 1 form sperm.
8. Dominant: It is an Allele that expresses its trait even in the presence of an alternative alleles i.e. Heterozygous condition. Example: Height of stem cell Tt.
9.Recessive: It is an Allele that not expresses its trait in the presence of alternative Allele i.e. Homozygous. It can be express only in the presence of another identical Allele.
Example: tt.
10. Heterozygous: Hybrid which contain both allele i.e. Homozygous condition . It can be express only in the presence of another identical allele.
Example: Tt
11.Homozygous: They are true breeders. An individual possesing dis-similar allele for particular traits this called Homozygous. Both the genes of a characters are identiacal said to be Homozygous / genetically pure they produce one type of gametes only dominant or only recessive
Example: tt / TT
12.Genotype: Internal Hereditary, information that contain genetic code genotype it is actually set of allele. It is the genetic constitution of organism.
13. Phenotype: Outer expressed trait / characters . It is the physical appearance of organism.