Law of Segregation

Law of Segregation is one of the fundamental principles in genetics, postulated by Gregor Mendel in the 19th century. It is also known as Mendel's First Law and it describes how pairs of genetic traits are separated into reproductive cells. The segregation of genes explained by this law is the basis for the understanding of the inheritance of traits.

Overview

The Law of Segregation states that every individual organism contains two alleles for each trait, and that these alleles segregate (separate) during meiosis, so that each gamete contains only one of the alleles. An offspring thus receives a pair of alleles for a trait by inheriting homologous chromosomes from the parent organisms: one allele from each parent.

Mendel's Experiments

Gregor Mendel, an Austrian monk, conducted experiments on pea plants in the mid-19th century. He observed that the plants' offspring retained traits of the parents. Mendel's experiments led him to conclude that traits are inherited as discrete units, now known as genes. He formulated the Law of Segregation after observing that certain traits showed up in offspring without any blending of parent characteristics.

Implications

The Law of Segregation is fundamental to the field of genetics. It explains why offspring inherit one version of a trait from each parent and why traits do not blend in offspring. This law is used in predicting the outcome of genetic crosses. It is also the basis for understanding genetic disorders and diseases.

See Also

• Mendelian inheritance
• Genetics
• Gregor Mendel
• Gene
• Allele
• Meiosis