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Figure 14 shows a banana plantation - Edexcel - GCSE Biology - Question 9 - 2020 - Paper 1
Question 9
Figure 14 shows a banana plantation. After the bananas have been harvested, the old plants are cut down. The suckers then develop into mature plants producing the n... show full transcript
Worked Solution & Example Answer:Figure 14 shows a banana plantation - Edexcel - GCSE Biology - Question 9 - 2020 - Paper 1
Step 1
Describe the function of a meristem in the growth of a plant.
Answer
A meristem is a region of undifferentiated cells in plants that is capable of division and growth. These cells can divide by mitosis to produce new cells, which can then differentiate into various types of specialized cells that contribute to plant tissues and organs. Meristems are essential for the growth of roots and shoots, allowing plants to extend in height and breadth.
Step 2
Describe how the student would prepare a microscope slide using these cells.
Answer
To prepare a microscope slide using cells from a meristem, the student should follow these steps:
- Use a sharp blade to cut a very thin section (a few cells thick) from the meristem tip to ensure that light can pass through.
- Place the thin section onto a clean microscope slide.
- Add a drop of water or mounting medium to the slide to prevent dehydration and to see the cells clearly.
- Carefully place a coverslip over the tissue to avoid air bubbles and to protect the specimen.
Step 4
Step 5
Describe the structure of DNA and how it can be extracted from plant cells.
Answer
DNA is a double helix composed of two long strands of nucleotides twisted around each other. Each nucleotide consists of a sugar (deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). To extract DNA from plant cells, the following steps are typically followed:
- Cells are broken down using physical methods (like grinding) or chemical means (such as a detergent).
- An extraction buffer containing salt and ethanol is added to separate DNA from proteins and other cellular debris.
- The mixture is filtered, and cold alcohol is slowly added to precipitate the DNA, which can then be collected and rinsed.