The nucleosome model explains the packaging of histone proteins and DNA in the chromatin material which forms the chromosome.

Correct Option: A

The nucleosome model explains the packaging of histone proteins and DNA in the chromatin material which forms the chromosome.

Purine is an organic nitrogenous base sparingly soluble in water, that gives rise to a group of biologically important derivatives, notably adenine and guanine, which occur in nucleotides and nucleic acids (DNA and RNA).

Correct Option: D

Purine is an organic nitrogenous base sparingly soluble in water, that gives rise to a group of biologically important derivatives, notably adenine and guanine, which occur in nucleotides and nucleic acids (DNA and RNA).

Theodor O. Diener discovered the Potato Spindle Tuber Viroid (“PSTVd”), the first viroid ever identified, in 1971. PSTVd is a small, circular RNA molecule. Dr. Diener discovered that the pathogen causing potato spindle tuber disease is not a virus, as previously believed, but a much smaller, free RNA molecule.

Correct Option: D

Theodor O. Diener discovered the Potato Spindle Tuber Viroid (“PSTVd”), the first viroid ever identified, in 1971. PSTVd is a small, circular RNA molecule. Dr. Diener discovered that the pathogen causing potato spindle tuber disease is not a virus, as previously believed, but a much smaller, free RNA molecule.

HIV viruses does not follow central dogma. Central dogma is a one way flow of information from DNA to mRNA and then to protein.

Correct Option: D

HIV viruses does not follow central dogma. Central dogma is a one way flow of information from DNA to mRNA and then to protein.

Infections proteins are rich in prions. Prions are made of proteins without nucleic acid. It is the causal agent of scrapie disease of sheep.

Correct Option: B

Infections proteins are rich in prions. Prions are made of proteins without nucleic acid. It is the causal agent of scrapie disease of sheep.