Mutagens
Mutagens Any extracellular physical or chemical factor which can cause mutations or increase the frequency of mutations in organism is termed as mutagen. In other words, the specific factors …
Category: Biology
Polyploidy
Polyploidy Polyploidy is the state of a cell or organism having more than two sets of chromosomes. There are mainly three different kinds of polyploids, namely, autopolyploids, allopolyploids and …
Euploidy
Euploidy In euploidy the number of chromosomes is the multiple of the number of chromosomes in a single set. Euploids can be monoploid, diploids or polyploids. Monoploidy and Haploidy …
Aneuploidy
Aneuploidy Aneuploidy means presence of chromosome number which is different than a multiple of basic chromosome number. In other words, aneuploidy is the presence of an abnormal number of …
Chromosomal Aberrations
Chromosomal Aberrations Chromosomal aberrations are abnormalities in the structure or number of chromosomes which are often responsible for genetic disorders. The structural changes in the chromosomes include: Deletion or …
Crossing Over
Crossing Over Crossing over may be defined as the recombination of linked genes brought as a result of interchange of corresponding parts between the chromatid of a homologous pair …
Linkage
Linkage The phenomenon of inheritance of genes together and to retain their parental combination even in the offspring is termed as linkage. Mendel’s principle of independent assortment shows exception. …
Pleiotropy and Polygenic Intheritance
Pleiotropy Genes that affect multiple, apparently unrelated phenotypes, are termed as pleiotropic genes and the phenomenon is termed as pleiotropy. The term pleiotropy is derived from the Greek word …
Blood Groups
Blood Groups Blood group is inheritable. ABO blood system in humans is triallelic system that generates six genotypes. The loss of blood due to accident or disease creates blood …
Epistasis and Supplementary Gene
Epistasis Epistasis is the phenomenon where the effect of one gene (locus) is dependent on the presence of one or more ‘modifier genes’. Any gene or gene pair that …