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Figure 2 shows xylem and phloem from the stem of a plant - Edexcel - GCSE Biology - Question 2 - 2022 - Paper 1
Question 2
Figure 2 shows xylem and phloem from the stem of a plant. (i) Living cells in phloem use energy to transport sucrose. Which organelles release energy in living cel... show full transcript
Worked Solution & Example Answer:Figure 2 shows xylem and phloem from the stem of a plant - Edexcel - GCSE Biology - Question 2 - 2022 - Paper 1
Step 1
Living cells in phloem use energy to transport sucrose. Which organelles release energy in living cells?
Answer
The organelles that release energy in living cells are mitochondria. Mitochondria are known as the powerhouse of the cell as they generate ATP (adenosine triphosphate) through the process of cellular respiration, which is essential for various cellular activities including the transport of nutrients like sucrose.
Step 2
Describe two features of the structure of xylem vessels that can be seen in Figure 2.
Answer
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Lignified walls: Xylem vessels have walls thickened with lignin, which provides structural support and helps prevent the collapse of the vessels, allowing them to withstand the negative pressure generated during water transport.
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Continuous lumen: Xylem vessels are formed from elongated cells that lose their cytoplasm, creating a continuous hollow lumen. This feature facilitates the efficient upward movement of water and minerals from the roots to the leaves.