Inventors and Scientific Discoveries

In 1909, Rutherford discovered nucleus in his famous gold foil experiment.

Briggs and King discovered that normal hatched tadpoles can be obtained by transplanting the nucleus of a blastula cell to the enucleated eggs of Rana pipiens. This finding provided an initial answer to the long-standing question of whether the process of development and cell differentiation requires a loss or stable change in the genetic constitution of cells.

Har Govind Khorana synthesized artificial gene in a test tube in the year 1969.

Har Gobind Khorana is widely recognized for his pioneering work in deciphering the genetic code and synthesizing the first artificial gene, which laid the foundation for genetic engineering.

In 1973 Herbert Boyer, of the University of California at San Francisco, and Stanley Cohen, at Stanford University, reported the construction of functional organisms that combined and replicated genetic information from different species. Their experiments dramatically demonstrated the potential impact of DNA recombinant engineering on medicine and pharmacology, industry and agriculture.

Henry Ford adopted the assembly line method in his automobile factories to mass-produce the Model T, revolutionizing industrial manufacturing.

• The intelligence system that was introduced to crack Enigma was code-named Ultra.
• It was only made available to a few British commanders in order to prevent the Germans from realising that it had been broken.

• Werner Von Braun worked on developing the V2 rockets that were used to attack Britain in 1944. Over 5000 rockets were launched at London, killing 2700 people and injuring many lives.
• At the end of the war, Braun surrendered to the US forces.

Root pressure is defined as the osmotic pressure in the root cell through which the water is translocated into leaves from the stem. The term root pressure was given by Stephan Hales. Thus the correct answer is option A.

External respiration is the process of gaseous exchange between the external environment and the blood stream. Antonie Lavoiser, a French Nobleman is considered as father of modern chemistry who along with chemistry also contributed in the fields of biology, finance and economics. He explained combustion and respiration in terms of chemical reactions involving oxygen. He showed that respiration was a slow combustion of organic material using inhaled oxygen. 

Newton used corpuscular theory to explain reflection and refraction of light. According to Sir Isaac Newton's Corpuscular Theory a luminous body continuously emits tiny, light and elastic particles called corpuscles in all directions. When these particles fall on the retina of the eye, they produce the sensation of vision.

John Dalton 1808, believed that matter is made up of extremely minute indivisible particles, called atoms which takes part in chemical reactions. These particle can neither be created nor be destroyed.

• Moist vapour theory was proposed by a Greek philosopher Pythagoras.
• According to this theory a certain moist vapour is transmitted from the male towards the female during the fertilization and it develops into an embryo.
• From where the later new organism is developed.
• Hence the correct option is B.

The humus theory, which posits that plants derive their nourishment directly from soil organic matter (humus), was a widely held belief in early plant physiology, notably supported by Aristotle.