NEET Biology: Principles of Inheritance and Variation Notes

Heredity and Genetics

• Heredity is the transmission of characteristics from parents to offspring through the passing of genetic information.

Branch of Biology

• The branch of biology that deals with the principles and mechanisms of inheritance and variation is Genetics.

Location of Genes

• Genes are located in the chromosomes of an organism's cells.

Continuity of Gene Pool

• The process that maintains the continuity of the gene pool is reproduction.

Father of Genetics

• Gregor Mendel is known as the 'Father of Genetics'.

Cause of Variation

• Variation among individuals of a species is caused by differences in their genetic makeup and the interaction of genes with the environment.

Units of Inheritance

• Mendel called the units passed from parents to offspring 'factors', which are now known as genes.

Law of Independent Assortment

• The law of inheritance that states that alleles for different traits are inherited independently is the Law of Independent Assortment.

Gametes in Dihybrid Cross

• In a dihybrid cross, heterozygotes produce 4 different kinds of gametes.

Incomplete Dominance

• The term used when neither of the two alleles is dominant and the phenotype of the heterozygote shows a mixture of the two parents' traits is Incomplete Dominance.

Blood Group Allele

• The allele 'AB' is NOT a blood group allele in humans controlled by the gene I.

Purpose of Test Cross

• The purpose of a Test Cross in genetics is to determine the genotype of an organism with a dominant phenotype.