Tag: molecular genetics

Steroid hormone are chemical messengers that interact or bind with the DNA inside the nucleus

George Beadle and Edward Tatum gave molecular definition of a gene while working on nutritional mutants in Neurospora. They exposed spores of the fungus Neurospora crassa to X-rays and other agents which damage DNA and cause alterations in DNA sequence (mutations). They observed that mutant fungal strains which lacked one or another specific enzyme, sometimes results in the failure of an entire metabolic pathway. It was concluded that a gene is a segment of genetic material that codes for one enzyme; the one gene–one enzyme hypothesis which was modified to one gene–one polypeptide, because many genes products are not enzymes and many gene code for one polypeptide of a multi-subunit protein. Correct option is C.

The one gene-one enzyme hypothesis is the idea that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway. The concept was proposed by George Beadle and Edward Tatum in an influential 1941 paper.  Beadle and Tatum noted that it was "entirely tenable to suppose that these genes which are themselves a part of the system, control or regulate specific reactions in the system either by acting directly as enzymes or by determining the specificities of enzymes".

Beadle and Tatum did classical experiments on Neurospora crassa to prove that in a multistep biochemical pathway, each step is controlled by different enzymes and each of these enzymes are encoded by specific gene. This is called as one gene one enzyme hypothesis. Option A is the correct answer.

Beadle and Tatum did classical experiments on Neurospora crassa to prove that in a multistep biochemical pathway, each step is controlled by different enzymes and each of these enzymes are encoded by specific gene. This is called as one gene one enzyme hypothesis. Option A is the correct answer.

The one gene - one enzyme hypothesis is the idea that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway. The concept was proposed by George Beadle and Edward Tatum in an influential 1941 paper on genetic mutations in the mold Neurospora crassa.

One gene one enzyme was given by Beadle & Tatum in which he explains the concept that one gene is capable of producing one enzyme only and is responsible for one individual step in the metabolic pathway.

The one gene - one enzyme hypothesis is the idea that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway. Beadle and Tatum proposed this concept.