scientist, discoveries & inventions MCQ section 2 Practice Questions Answers Test with Solutions & More Shortcuts

Answer: (d)

Answer: (b)

Mycobacteriumleprae, the causative agent of leprosy, was discovered by G. H. Armauer Hansen in Norway in 1873. Hansen observed a number of non-refractile small rods in unstained tissue sections.

The rods were not soluble in potassium lye, and they were acid- and alcohol-fast. In 1879, he was able to stain these organisms with Ziehl’s method and the similarities with Koch’s bacillus (Mycobacterium tuberculosis) were noted.

Answer: (d)

Answer: (a)

Palaeontology is the study of fossils to determine the structure and evolution of extinct animals and plants and the age and conditions of deposition of the rock strata in which they are found. Body fossils and trace fossils are the principal types of evidence about ancient life.

Answer: (c)

A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons.

On May 16, 1960, Theodore H. Maiman operated the first functioning laser, at Hughes Research Laboratories, Malibu, California, ahead of several research teams, including those of Townes, at Columbia University, Arthur Schawlow, at Bell Labs, and Gould, at the TRG (Technical Research Group) company.