DNA Structure Quiz

Which of the following is not found within DNA?

• Thymine

• Phosphodiester bonds

• Complementary base pairing

• amino acids

Which of the following statements about base pairing in DNA is incorrect?

• Purines always base pairs with pyrimidines.

• Adenine binds to guanine.

• Base pairs are stabilized by hydrogen bonds.

• Base pairing occurs at the interior of the double helix.

Diameter or width of double helix of 'DNA' is, approximately

• 20 Å

• 2 nm

• Both A & B

• 10 nm

Two strands of 'DNA' are held together by:

• Covalent bonding

• Hydrogen bonding

• Ionic bonding

• Metallic bonding

Two strands of DNA are:

• Parallel to each other

• Antiparallel to each other

• Similar to each other

• Linear

Distance between two neighbouring base pairs is, approximately:

• 3.4 Å

• 26 Å

• 20 Å

• 2.4 Å

Double 'helical' structure of DNA was identified in the year _________.

Two 'polynucleotides' are not identical, but:

• Complementary to each other due to phosphate

• Complementary to each other due to base pairs

• Complementary to each other due to hydrogen bonding

• Complementary to each other due to pentose sugar

In DNA, each turn of helix is nearly:

• 3.3nm

• 4.4nm

• 3.4 nm

• 2.5 nm

The bases are held together in a DNA double helix by hydrogen bonds. These bonds are ______.

• Ionic bonds

• Covalent bonds

• Non-covalent bonds

• Van der Waals forces