Read the the given statements and answer the questions that follow :- When Streptococcus pneumoniae bacteria were grown on a culture plate some produced smooth shiny colonies and others produced rough colony. Mice infected with the S strain died from pneumonia infection but mice infected with the R strain didn't develop pneumonia. When Griffith heat killed the S strain bacteria and injected it into the mice, the mice did not die .While on the other hand when he injected S strain heat killed bacteria with live R strain into the mice ,they died.

What is the cause for the smooth colony produced by bacteria on the culture plate?

Mucous polysaccharide coat Acidic coat Basic coat None of these

Mucous polysaccharide coat

Griffith had isolated two very similar types of bacteria from mice. These were actually two different varieties, or strains, of the same bacterial species. Both strains grew very well in culture plates in Griffith's lab, but only one of them caused pneumonia. The disease-causing bacteria (S strain) grew into smooth colonies on culture plates, whereas the harmless bacteria (R strain) produced colonies with rough edges. Due to the presence of mucous polysaccharide coat in the S strain of bacteria they produced smooth colonies.