Question

Christian Gram belongs to which country?
A. Italy
B. Sweden
C. Denmark
D. Germany

Answer 1

Hint: Hans Christian Joachim Gram was a famous Danish bacteriologist because he developed a technique called gram staining which is a very standard technique to classify various types of bacteria and make them more visible under the microscope. He was born on 13th September, 1853 in Copenhagen, Denmark.
In Berlin, 1884 he developed the two types of bacteria on the basis of their cell wall structure and their sustainability with Gram’s stain.

Complete answer: Christian Gram findings published in 1884 in a journal from where the two terms coined are Gram negative bacteria and Gram positive bacteria.
In Gram negative bacteria, the cell envelope shows two layers, the outer membrane, a thin layer of peptidoglycan and plasma membrane. They also contain special proteins called porins. In this type of bacteria the stain is washed due to the high lipids contents in the cell wall which get dissolved in organic solvents like alcohol. They give purple colour. Example- E.coli
In Gram positive bacteria, the cell wall contains 70-80% peptidoglycan and little amount of lipids. The cell wall contains teichoic acid from receptor sites and surface antigens. It can be observed by the help of stains like safranin. They give blue colour after staining. Example of gram positive bacteria is bacillus subtilis.

So, the Christian Gram belonged to Denmark and was a very famous Danish bacteriologist.

Note: Gram’s initial work was concerned with RBCs in men. He was the first to recognize that the macrocytes were characteristic of pernicious anaemia. He was also appointed as a professor of medicine in the University of Copenhagen in 1900. He published the four volumes of clinical lectures which were widely used in Denmark. He retired in 1923 and died on 14th November 1938.