CHROMOSOMAL THEORY OF INHERITANCE
INTRODUCTION
Gene is the functional unit of hereditary material which is linearly arranged on chromosomes. Chromosomes are bearer of genes which are located at specific sites called loci along them.
The chromosome theory of inheritance or the Sutton–Boveri theory states: chromosomes, which are found in all dividing cells and pass from one generation to the next, are the basis for all genetic inheritance.
Important Points
- The chromosome theory of inheritance is postulated by Walter Sutton in 1902 and 1903 and by Theodor Boveri roughly during the same period. So the chromosomal theory of inheritance is also called Sutton-Boveri theory.
- Theodor Boveri, while working on sea urchins, observed that proper embryonic development does not occur unless chromosomes are present. It means all the chromosomes had to be present for proper embryonic development . In the same year, Walter Sutton observed the separation of chromosomes into daughter cells during meiosis, while working on grasshopper.
Read also.. MITOSIS & MEIOSIS- CELL DIVISION
- The chromosome theory of inheritance or the Sutton–Boveri theory identified chromosomes as the genetic material responsible for Mendelian inheritance.
- T.H. Morgan, while working on drosophilla observed that while crossing a set of characteristics, two genes did not segregate as per Mendel’s law of segregation. If two genes were present on the same chromosome, the probability of getting a parental combination was much higher in the next generation compared to the non-parental combination. This tendency of genes was termed as linkage. The term genetic recombination describes the non-parental gene combinations in a dihybrid cross.
Recombination
CONCLUSION
This theory states that chromosomes are the carrier of genetic heredity. Neither Mendelian genetics nor gene linkage is perfectly accurate; nevertheless, chromosome behavior involves segregation, independent assortment, and occasionally, linkage.
Read more….
MENDEL’S LAW OF INHERITANCE
DIFFERENCE BETWEEN GENE AND ALLELE
LINKAGE AND CROSSING OVER-AN OVERVIEW
WHAT IS CHROMOSOME- AN OVERVIEW
TYPES OF CHROMOSOME-STRUCTURE&DEFINITION
HOMOLOGOUS CHROMOSOMES-AN OVERVIEW & FUNCTION
DNA REPLICATION- FACTS & PROCESS
DIFFERENCE BETWEEN PHENOTYPE AND GENOTYPE