Biology 9700 · AS & A Level · Respiration

Respiration — practice question

A respirometer may be used to determine the respiration rate of small invertebrates, for example the common woodlouse, $\textit{Oniscus asellus}$. Fig. 8.1 shows a common woodlouse and Fig. 8.2 shows a respirometer.
(a(i))[1]

Name the solution X.

(a(ii))[1]

A respirometer may be used to investigate how temperature affects the rate of respiration in organisms. Suggest one factor that would have to be considered when woodlice are used instead of germinating seeds.

(a(iii))[1]

During respiration, oxygen is taken up by the woodlice and the coloured liquid sinks down the graduated tube. Name the stage of aerobic respiration in which oxygen is used.

(b(i))[2]

Table 8.1 gives the results. Complete Table 8.1 by working out the rates of oxygen uptake at $15^{\circ}\text{C}$ and $25^{\circ}\text{C}$.

(b(ii))[3]

Explain why the rates of oxygen uptake differ at $15^{\circ}\text{C}$ and $25^{\circ}\text{C}$.

(b)

Fig. 8.2 shows a respirometer that was used to investigate how temperature affects the rate of respiration in woodlice.

(c)[5]

When oxygen is absent, pyruvate produced during glycolysis is converted to ethanol in yeast cells and to lactate in mammalian tissue. Compare the pathways used to convert pyruvate to ethanol or to lactate.

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