Question

Match the scientists and their contribution given in columns.

Scientists	Contributions
A	W.His	P	X-ray crystallography
B	Knoll and Ruska	q	Column chromatography
C	Bragg	r	Microtome
D	Tswett	s	Electron microscope

A. A-r, B-s, C-p, D-q
B. A-,s B-q, C-r, D-p
C. A-r, B-s, C-q, D-p
D. A-p, B-r, C-s, D-q

Answer 1

Hint:
After treating the animal flesh with the acids and then slicing it very thinly with the microtome, scientist W.His were able for the further research.
Bragg was the joint recipient with his father William Henry Bragg for the Nobel Prize in Physics, for their services in the analysis of crystal structure of X-ray which was an important step in the development of X-ray crystallography process.

Complete step by step answer:

Scientists	Contributions
A	W.His	r	Microtome
B	Knoll and Ruska	s	Electron microscope
C	Bragg	P	X-ray crystallography
D	Tswett	q	Column chromatography

W.His (Wilhelm His) is a scientist who invented the Microtome.
Knoll was a German engineer and the physicist Ruska is acknowledged for the development of the first electron microscope and also after Ruska was awarded with the Nobel Prize for his work in electron optics.
Bragg (William Lawrence Bragg) was a physicist and the x-ray crystallographer. Also he discovered Bragg's law of x-ray diffraction.
Tswett (M.S. Tswett) is the person who represented the first discovery on column chromatographic technique.
Therefore, the correct answer is option A.
Additional information:
W.His introduced the word endothelium, differentiating the internal membranes which had formerly been grouped with the epithelia and developing an understanding of their relationship to the germ layers in the process of development.
Knoll was born in the Wiesbaden and completed his studies in Munich and also at the Technical University of Berlin, where he got his doctorate degree in the Institute for High Voltage Technology. Afterwards he became the leader of an electron research group, where he and his co-worker Ruska invented the electron microscope.
Bragg was an Australian-born British physicist and also the X-ray crystallographer and the discoverer of Bragg's law of X-ray diffraction which is the basis for the determination of the crystal structure.
Tswett invented the process of chromatography during his research on the plant pigments. He uses the liquid-adsorption column chromatography with the calcium carbonate as adsorbent and the mixture of petrol ether or ethanol as the eluent for the separation of the chlorophylls and the carotenoids.
Note:
The microtome helps in the making of thin slices of tissue.
An electron microscope is the microscopes which use the beam of electrons as the source for the illumination. It is the special type of microscope with a high resolution of images.
X-ray crystallography is the tool used to determine the atomic and the molecular structure of a crystal.
The column chromatography is mostly used by the organic chemists to purify the liquids.