Take this Quiz: A-Level Biology: DNA, RNA and ATP | Zestly

Question 1

Which specific chemical bond links the phosphate group of one nucleotide to the deoxyribose sugar of the adjacent nucleotide in a DNA strand?

Accepted Answer

Phosphodiester bond

Question 2

In the Meselson-Stahl experiment, what result after two generations of replication in a nitrogen-14 medium provided evidence for the semi-conservative model?

Accepted Answer

Two bands were observed: one light (14N) and one intermediate (14N/15N).

Question 3

Which of the following are true regarding the structural and functional differences between mRNA and tRNA?

Accepted Answer

mRNA is a linear molecule, whereas tRNA has a cloverleaf shape.

Question 4

Why is ATP considered an 'immediate' energy source in biological systems?

Answer

It is a long-term storage molecule found in the mitochondria.

Answer

It can be synthesized from glucose in a single step.

Answer

It releases a small, manageable amount of energy through a single hydrolysis reaction.

Answer

It is a large polymer that provides sustained energy release.

Question 5

Which of the following ions are correctly matched with their biological importance?

Answer

Fe2+: component of the haem group in haemoglobin.

Answer

Na+: involved in the co-transport of glucose and amino acids.

Answer

H+: determines the pH of solutions and affects enzyme activity.

Answer

Phosphate: acts as a buffer to maintain blood pH.