AGB 121: Principles of Animal Genetics and Population Genetics (2+1)

LETHALS

• Genes which affect the viability as well as the visible traits of an organism are called lethal genes and the phenomenon is called lethality.
• Lethal genes can be recessive , dominant , conditional, semilethal / sublethal, or synthetic, depending on the gene or genes involved.
• If the lethal effect is dominant and immediate in expression, all individuals carrying the gene will die and the gene will be lost.
• Dominant lethal genes are expressed in both homozygotes and heterozygotes. All individuals carrying the genes will die and the genes will be lost in populations.
• Recessive lethal allele carried in the heterozygous condition has no effect but they cause death when an organism carries two copies of the lethal allele.
• Recessive lethal may come to expression when mating between carriers occurs.

 To view "Lethal Genes Animation"