1.Mosaic - An individual with two cell types or more, comprising of different chromosome number or structure
2.Genetic Counselling - A communicative procedure that undertakes to deal with the problems that rise in a family with the occurrence or the risk of occurrence of a genetic abnormality
3.Pedigree - A pedigree involves recording a family's history and making use of a standard set of symbols to represent the status of each member of the family
4.Allele - An allele is an alternative form of a gene loated on a given locus of a chromosome
5.Gene - Genes are located on the chromosomes and carry the information representing a protein
6.Chromosomes - Chromosomes are structures made up of DNA and proteins found in the cells of all organisms.The number of chromosomes is species- specific.In humans it is 46.
7.DNA - The DNA is the basic unit of heredity and is known as the blue print of life.It carries the genetic codes which stores the necessary information for all organisms.
8.Genotype - Genotype indicates the genetic constitution of an organism
9.Phenotype - Phenotype refers to the physical appearance of an organism which is controlled by the genotype and the enviornment
10.Haploid Cell - A cell having only one set of chromosomes,ie.23 numbers in humans
11.Diploid Cell - Having two sets of chromosomes,46 numbers in humans
12.Hybrid - An offspring of parents belonging to two different species,example mule which is the offspring of a horse and donkey
13.Mutation - An inheritable change in the gene or the chromosome
14.Wild Type - An organism having a normal phenotype
15.Mutant - An organism harboring a mutation
16.Trisomy - A condition ,which arises due to the presence of an extra chromosome.An example is Down syndrome, where the individual has an extra chromosome 21
17.Mitosis - A division by which the cells reproduce, wherein the resultant cells are the replica of the parent cell.
18.Meiosis - A special kind of cell division,called reduction division, that takes place in the testes and the ovaries, which produces eggs and sperms that are haploid
19.Consanguinous marriage - A marriage between two closely related individuals
20.Euploidy - When an organism has the regular chromosome number,example 46 numbers in humans, it is euploid.
21.Aneuploidy - When an organism has an abnormal number of chromosomes as in Down Syndrome,it is known as aneuploidy.