Question

The action of insulin was first demonstrated by
A. Banting and Best
B. Darwin
C. Lamarck
D. Watson and Crick

Answer 1

It was first demonstrated by a Canadian physician who employed different techniques to isolate secretions from the islet cells from the dog's pancreas. Later, he and his assistant were best known for the extraction of insulin from the animal pancreas to treat glycosuria in dogs and then later in humans.

Complete answer:
It was in 1869, paul Langerhans, a medical student from berlin discovered the islets of Langerhans. After this discovery, several researchers tried to identify and extract the secretions of these cells. It was only during 1920, did Fredrick Banting, a Canadian physician, was capable of blocking the ducts of the pancreas to produce a crude secretion of insulin. When injected the extract into a diabetic dog he saw a reduction in the glycosuria condition in the dog. He approached J.J.R Macleod, a professor of physiology at the University of Toronto about his finding, who suggested he conduct more proper experiments and gave him the laboratory and an assistant who was Charles Best. Both Fredrick Banting and Charles Best were successfully able to isolate insulin from a dog’s pancreas which when injected in another diabetic dog significantly reduced glycosuria conditions. Fredrick was also capable of finding new methods to extract insulin from the cow pancreas at much easier and at larger quantities. But when administered to humans it showed severe immunological reactions. It was only after collaboration with Elli illy company was a purified insulin extract suitable for human administration was prepared. In1923 Fredrick Banting and Charles Best won the nobel prize in physiology for their discovery of the activity and isolation of insulin.
Therefore, the correct answer is option A.

Note: Charles Darwin was a British biologist who wrote the book on evolution and coined the theory of natural selection. Similarly, Jean- Baptize Lamark gave the theory of Lamarckism which stated that inheritance of acquired traits. Watson and Crick are Nobel laureates who won the Nobel prize for the discovery of the double helix structure of the DNA.