We explain what the chromosome theory of inheritance formulated by Sutton and Boveri is. Also, how is it based on Mendel’s laws.
What is the chromosome theory of heredity?
The chromosome theory of inheritance or chromosome theory of Sutton and Boveri is the scientific explanation of the transmission of certain characters through the genetic code contained in the living cell , which occurs between one generation of individuals and the next.
This theory was developed by scientists Theodor Boveri and Walter Sutton in 1902 . Despite the distance between them, Boveri (German, 1862-1915) and Sutton (American, 1877-1916) independently drew the same conclusions based on previously existing knowledge of heredity and cell function.
It was a debated and controversial theory until the year 1915, when the experiments with Drosophila melanogaster flies by the American scientist Thomas Hunt Morgan (1856-1945) confirmed it completely.
The chromosome theory of heredity studied the genes , that is, the DNA segments that encode specific proteins , also called “hereditary factors” in his studies on heredity Gregor Mendel (1822-1884). Specifically, he postulated that genes are located within the cell’s chromosomes , which are located within the cell nucleus .
The existence of chromosomes was already known and it was known about their replication during cell division, but from then on they became much better known: it was learned that they come in homologous pairs, one from the mother and one from the father, so reproductive cells or gametes must provide each individual with exactly half of the genetic material.
This theory allowed us to understand why certain characters are inherited and others are not , that is, why one allele is transmitted and another is not, since they are independent from each other, as they are located on different chromosomes. For example, the chromosome that contains information about the sex of the individual is different from the chromosome that contains information about the color of his eyes, etc.
It can help you: Mutation
Mendel’s Laws
Mendel discovered that not all genetic information manifests itself.
The main antecedent of the chromosomal theory of heredity is constituted by the studies of Gregor Mendel , who carried out a series of experiments and follow-ups among pea plants, managing to formulate the well-known Mendel’s Laws on heredity in 1865.
His experiences were essential to understand how genetic traits are passed from one generation to the next. First, he discovered that there are two types of traits (genes): dominant (AA) or recessive (aa) , depending on what is manifest in the individual. or not, being in the latter case a carrier of the non-manifest gene.
Thus, Mendel proposed the existence of “pure” (homozygous) individuals, whether dominant or recessive (AA or aa), and other heterozygous individuals resulting from genetic mixing and transmission (Aa), for each specific hereditary character.
This approximation was the first human attempt to describe the laws that govern genetics, and despite the fact that its results were recognized much later, it is a revolutionary contribution for its time, the foundation of everything that would come later.
