Molecular Basis of Inheritance - Class 12 Boards Botany

Molecular Basis of Inheritance

Discovery and Structure of DNA DNA is a long, acidic polymer present in the nucleus, first observed by Friedrich Miescher in 1869, who called it "nuclein." Altmann later identified its acidic nature. Watson and Crick, using X-ray diffraction data from Rosalind Franklin, proposed the...

Which scientist's X-ray diffraction data helped Watson and Crick propose the double helical structure of DNA?

Rosalind Franklin

What is the key structural difference between DNA and RNA sugars?

DNA has H at second position, RNA has OH

Which scientist's X-ray diffraction data helped Watson and Crick propose the double helical structure of DNA?

Rosalind Franklin

What is the key structural difference between DNA and RNA sugars?

DNA has H at second position, RNA has OH

What is the difference between a nucleotide and a nucleoside?

A nucleoside consists of a sugar (deoxyribose or ribose) covalently linked to a nitrogenous base. A nucleotide is the basic monomeric unit of DNA and RNA, composed of a sugar, a nitrogenous base, and a phosphate group, meaning it is a nucleoside with an additional phosphate group.

Explain the role and formation of a phosphodiester bond in DNA.

A phosphodiester bond is a strong covalent bond that forms the sugar-phosphate backbone of DNA and RNA. It links the 3' carbon of one sugar to the 5' carbon of an adjacent sugar via a phosphate group, connecting adjacent nucleotides in a polynucleotide chain.