Biology 5090 · O Level · Anaerobic respiration

Anaerobic respiration — practice question

Two distinct strains, A and B, from the same microorganism species are used to make bread and beer (an alcoholic drink). Fig. 1.1 shows the amount of gas given off by the strains while they are in use.
(a(i))[1]

Name this kind of microorganism.

(a(ii))[1]

Name the gas given off by this microorganism during the production of bread and beer.

(b(i))[3]

Fig. 1.1 shows the gas released by strain B at a temperature of $18\ ^\circ\text{C}$. Draw a curve on Fig. 1.1 to show the effect on strain B of increasing the temperature by $10\ ^\circ\text{C}$.

(b(ii))[2]

Name two other outside factors that would alter the shapes of the curves shown in Fig. 1.1.

(c)[3]

Strain A tastes sweet and strain B tastes bitter. Suggest which strain is used to make bread. Give reasons for your answer.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: yeast; fungus; Saccharomyces

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