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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
Meristems are regions in a plant's growth that contain undifferentiated cells, meaning the cells have not yet specialized. Their primary function is to divide and produce more cells through the process of mitosis. This process enables the growth of new tissues and organs, allowing the plant to expand in size and develop.
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 would follow these steps:
- Collecting a Sample: Use a sharp blade to take a small sample of the meristem tissue.
- Mounting the Sample: Place the tissue sample onto a clean microscope slide.
- Adding a Stain (if necessary): To enhance visibility, the student may add a drop of stain (like methylene blue) to the sample.
- Covering the Sample: Gently place a cover slip over the tissue to avoid air bubbles and protect the sample.
- Viewing: Finally, place the slide under the microscope to observe the cells.
Step 4
Step 5
Describe the structure of DNA and how it can be extracted from plant cells.
Answer
DNA is composed of two long strands forming a double helix, made up of nucleotides that consist of a sugar, phosphate group, and nitrogenous bases (adenine, thymine, cytosine, and guanine). To extract DNA from plant cells, the following steps can be taken:
- Cell Lysis: Grind the plant tissue in a buffer solution that breaks down cell membranes.
- DNA Separation: Add detergent to break down the cell walls and dissolve membranes, followed by salt which helps to separate the DNA from proteins.
- Precipitation: Add cold alcohol (ethanol or isopropanol) to precipitate the DNA, making it visible.
- Collection: Use a pipette to collect the precipitated DNA, which can be seen as a white or cloudy substance.