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Figure 10 (a) Water lilies have stomata on the upper surface of the leaves - Edexcel - GCSE Biology Combined Science - Question 5 - 2020 - Paper 1
Question 5
Figure 10 (a) Water lilies have stomata on the upper surface of the leaves. Explain why water lilies have no stomata on the lower surface of the leaves. (ii) Gluco... show full transcript
Worked Solution & Example Answer:Figure 10 (a) Water lilies have stomata on the upper surface of the leaves - Edexcel - GCSE Biology Combined Science - Question 5 - 2020 - Paper 1
Step 1
Explain why water lilies have no stomata on the lower surface of the leaves.
Answer
Water lilies have no stomata on the lower surface of the leaves primarily because the lower surface is not exposed to the air. This means that gas exchange cannot occur, as there is no contact with atmospheric oxygen or carbon dioxide. Additionally, being submerged in water eliminates the need for stomata, as it would lead to a potential for water loss through transpiration.
Step 3
Describe how this sugar is transported from the leaves to the flowers of the water lily.
Answer
Sucrose is transported from the leaves to the flowers of the water lily through the phloem, the vascular tissue responsible for the transport of organic nutrients. The process involves the movement of sucrose from source cells in the leaves, where it is produced via photosynthesis, through the phloem to sink cells in the flowers, where it is utilized for growth and energy.
Step 4
Explain why this non-indigenous plant now covers the whole surface of the lake.
Answer
The non-indigenous water lily plant likely covers the whole surface of the lake due to its rapid growth and reproduction rates. It can outcompete local vegetation for resources such as sunlight and nutrients, leading to monopolization of space. Moreover, the absence of natural predators or competitors in its new environment allows for unrestricted expansion.
Step 5
Explain how the water lilies will affect the biodiversity of this lake.
Answer
The presence of water lilies can severely impact the biodiversity of the lake by dominating the habitat and limiting light penetration into the water. This can disrupt the growth of other aquatic plants and lead to decreased food resources for herbivorous species. As a result, the overall diversity of aquatic life can diminish, leading to changes in the ecosystem dynamics.