Plant Tissues, Organs, and Organ Systems

1) A group of students wanted to investigate water uptake by taking cuttings from different plant species with different sized leaves. They used a potometer to do this, as shown in the image below. Explain what is recorded to represented the uptake of water when using a potometer 1 Marks

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2) Give two variables which would need to be controlled in the experiments 2 Marks

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3) The results of the experiments seemed to suggest that plants with larger leaves had a faster uptake of water than those with smaller leaves. Suggest why 2 Marks

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4) The students wanted to ensure that the differences they observed in the rate of uptake were due to the size of the leaves, and not the number of stomata on each leaf. To do this, they looked at the different leaves under the microscope. Name the type of cell responsible for the opening and closing of the stomata 1 Marks

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5) The images below show three 0.15mm2 fields of view of the stomata present in the epidermis of one of the leaf species. Calculate the mean number of stomata present, and from this, the mean number of stomata per 1mm2 of leaf epidermis 2 Marks

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6) In the natural world, plants rely on mass transport systems to move substances from their roots, upwards, and around the rest of the organism. Define the term ‘transpiration stream’ 3 Marks

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7) Give an example of an adaptation a plant living in a very dry environment - such as a desert - may have, and explain how this helps it to conserve water 2 Marks

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8) The other method of mass transport in plants is translocation. Evaluate the differences between transpiration and translocation 4 Marks

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