This document summarizes key concepts of genetics and Mendelian inheritance. It defines terms like genotype, phenotype, gene, allele, locus, dominant and recessive alleles. It explains Mendel's laws of segregation and independent assortment using monohybrid and dihybrid crosses. Gamete formation and random fusion during fertilization are described. Phenotypes of homozygous dominant, heterozygous, and homozygous recessive genotypes for a single trait are defined. The role of environment on phenotypes is also mentioned.