Biology 9700 · AS & A Level · Structure of nucleic acids and replication of DNA

Structure of nucleic acids and replication of DNA — practice question

Blood cells originate from tissue stem cells in the bone marrow. These bone marrow stem cells pass through several mitotic cycles before developing into mature blood cells that function properly. Fig. 5.1 illustrates the three principal stages of the cell cycle.
(a)[2]

Explain the meaning of the term gene.

(b)[1]

Name the main stage of the cell cycle in Fig. 5.1 during which most mRNA and ATP is made.

(c(i))[3]

On Fig. 5.2: finish the ATP molecule diagram; write the base name in the space provided; write the sugar name in the space provided.

(c(ii))[1]

The base shown in Fig. 5.2 has a double-ring structure. State the term used for a base with a double-ring structure.

(d)[3]

Suggest and explain the role of mitosis in producing blood cells from the bone marrow stem cells.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: A particular stretch of DNA nucleotides

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