Inventors and Scientific Discoveries

The water frame, a spinning machine powered by a water wheel, was patented by Richard Arkwright in 1769.

In 1828, the German chemist Friedrich Wöhler obtained urea artificially by treating silver cyanate with ammonium chloride. 

The correct answer is oil. finn dorsett is sheep from which the nucleus was taken for cloning of dolly, whereas scottish black face ewe was used for implanticen of egq containing nucleus of finn dorseet sheep.

Dolly is the first sheep which was developed by the technique of cloning by Ian Wilmut in the year 1997. The sheep was developed from the diploid body cell. The somatic cell from the mother sheep was taken and the nucleus was injected into the egg cell which was cultured and transferred into the surrogate mother. This method is known as nuclear transfer. The sheep Dolly was identical in the characters with the mother who donated the diploid nucleus from the body cell.  

• Dolly was born on July 5, 1996, at Roslin Institute, the first mammal known to be cloned.
•  A cell taken from the mammary gland of a 6-year-old Finn Dorset ewe was cloned through a technique known as nuclear transfer. 
• The reproductive egg cells were removed from another female sheep, a ewe of a Scottish Blackface. 
• Scottish Blackface egg cells were then fertilized with the genetic material from the Finn Dorset mammary cells and they fertilized cell was transferred to the uterus of the surrogate mother. 
• On July 5, 1996, Dolly was born from one of the surrogate Blackface ewes which were identical to the Finn Dorset sheep. 

Louis Pasteur discovered the Pasteurization method of preserving milk in 1964. This method killed harmful bacteria that tend to grow in dairy products like milk especially in the absence of refrigeration.

Louis Pasteur discovered $Anti-Rabies Vaccine$ in the mid ${19}^{th}century$.

Guglielmo Marconi an Italian scientist discovered radio. He send and received his first radio signals in Italy in 1895.

Sir David Brewster invented Kaleidoscope.

In 1857, Pasteur showed that lactic acid fermentation is caused by living organisms, In 1877, working to improve the French brewing industry, Pasteur published his famous paper on fermentation,"Studies on fermentation". He defined fermentation (incorrectly) as "Life without air",but correctly showed that specific types of microorganisms cause specific types of fermentations and specific end-products.

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".