Fig. 1.1 is a transverse section through a leaf from the maize plant, Zea mays . Maize is a C4 plant. Fig. 1.1 (a) On Fig. 1.1, use label lines and letters to show: A – a cell in the epidermal layer B – a cell that contains PEP carboxylase. (i) Identify the cell type labelled C in Fig. 1.1. C = \_\_\_\_\_\_ (ii) Explain how the leaf anatomy shown in Fig. 1.1 adapts the C4 plant to maintain a high rate of photosynthesis at high temperatures. (c) Fig. 1.2 shows the results of…

Biology 9700/41 — October/November 2020

Cambridge A-Level · A Level Structured Questions · worked solutions for every part, with the mark scheme

questions

100

marks

120

minutes

Topics Genetic Technology · Inheritance · (outdated) Crop Plants · Selection and Evolution · Classification, Biodiversity and Conservation · Photosynthesis · +2 more

Q1(outdated) Crop PlantsPhotosynthesisFree sample

Fig. 1.1 is a transverse section through a leaf from the maize plant, Zea mays.

Maize is a C4 plant.

Fig. 1.1

(a)

On Fig. 1.1, use label lines and letters to show:

A – a cell in the epidermal layer

B – a cell that contains PEP carboxylase.

(b)

(i)

Identify the cell type labelled C in Fig. 1.1.

C = ______

(ii)

Explain how the leaf anatomy shown in Fig. 1.1 adapts the C4 plant to maintain a high rate of photosynthesis at high temperatures.

(c)

Fig. 1.2 shows the results of an experiment comparing the rate of carbon dioxide uptake in a C3 plant (Chenopodium album) and a C4 plant (Amaranthus retroflexus) in high and low carbon dioxide ( $\text{CO}_2$ ) conditions.

The rate of $\text{CO}_2$ uptake is used to measure the rate of photosynthesis.

Fig. 1.2

(i)

Using Fig. 1.2, compare the rates of photosynthesis in high $\text{CO}_2$ conditions in the C3 and C4 plants.

(ii)

Using Fig. 1.2, compare the rates of photosynthesis in low and high $\text{CO}_2$ conditions in the C4 plant between $30^{\circ}\text{C}$ and $35^{\circ}\text{C}$ and suggest an explanation for this difference.

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9 more questions

Q2Selection and Evolution · Inheritance · Genetic Technology14M
Q3Selection and Evolution · Classification, Biodiversity and Conservation · Genetic Technology8M
Q4Inheritance · Genetic Technology11M
Q5Inheritance10M
Q6—12M
Q7Energy and Respiration8M
Q8(outdated) Crop Plants · Classification, Biodiversity and Conservation9M
Q9Genetic Technology15M
Q10Homeostasis15M

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