Structure of the Nucleic acids

Which of the following components is absent in a nucleoside?

• Nitrogenous base

• Phosphate group

• Pentose sugar

• Purine or pyrimidine

• Glycosidic bond

Which of the following bases is classified as a purine?

• Cytosine

• Thymine

• Uracil

• Guanine

• None of the above

Which of the following correctly describes the bond linking nucleotides in DNA?

• Glycosidic bond

• Hydrogen bond

• 3'-5' phosphodiester bond

• Peptide bond

• Ionic bond

Which pair of bases forms three hydrogen bonds?

• A - T

• G - C

• A - U

• A - G

• C - T

Which nitrogenous base is present only in RNA?

• Adenine

• Cytosine

• Thymine

• Guanine

• Uracil

Which of the following is true regarding B-DNA?

• It is left-handed helix

• It has 12 base pairs per turn

• It is the most common form in nature

• Its bases are not complementary

• It occurs only in viruses

Which of the following is the most abundant RNA type in the cell?

• Messenger RNA (mRNA)

• Ribosomal RNA (rRNA)

• Transfer RNA (tRNA)

• Small nuclear RNA (snRNA)

• Heterogeneous nuclear RNA (hnRNA)

Which of the following proteins is associated with nuclear DNA in eukaryotic chromatin?

• SSB protein

• Actin

• Globulin

• Histones

Which histone subtype is involved in DNA packaging between nucleosomes?

• H1

• H2A

• H2B

• H3

• H4

What is the effect of high G-C content on DNA melting temperature?

• No effect

• Decreases melting temperature

• Increases melting temperature

• Makes DNA unstable

• Prevents denaturation