Biology 9700 · AS & A Level · Protein synthesis

Protein synthesis — practice question

A plasma cell is formed from an activated B-lymphocyte in the immune system. Once mature, plasma cells make and release antibody molecules.
(a(i))[3]

Describe the additional nuclear detail that can be observed with an electron microscope.

(a(ii))[2]

Explain why structures within cells, including ribosomes and the rough and smooth endoplasmic reticulum, are not visible with a light microscope.

(a)

Fig. 4.1 shows a drawing of a transmission electron micrograph of a plasma cell.

(b)[5]

Complete Table 4.1 by writing the letter for the event shown in Fig. 4.2 that matches the stage of the cell cycle listed. If a stage has no matching description, leave the space blank. Use each letter just once. One letter in Table 4.1 has already been filled in for you.

(c)[3]

Clonal expansion also gives rise to memory B-lymphocytes. Explain why clonal expansion and the production of memory B-lymphocytes are important in protecting a person against an infectious disease.

(d)[2]

Myasthenia gravis is an example of a disease in which the immune system cannot tell self from non-self. Explain what is meant by this statement.

Worked solution & mark scheme

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