Photo AI
8 (a) Apple trees show genetic variation: (i) State one possible cause of genetic variation in apple trees - Edexcel - GCSE Biology - Question 8 - 2023 - Paper 1
Question 8
8 (a) Apple trees show genetic variation: (i) State one possible cause of genetic variation in apple trees. (ii) The colour of an apple is an observable characteri... show full transcript
Worked Solution & Example Answer:8 (a) Apple trees show genetic variation: (i) State one possible cause of genetic variation in apple trees - Edexcel - GCSE Biology - Question 8 - 2023 - Paper 1
Step 1
Step 2
Step 3
Step 4
Give one advantage and one disadvantage of growing genetically identical apple trees.
Answer
An advantage of growing genetically identical apple trees is that they ensure uniformity in fruit quality and yield. A disadvantage is that they are more susceptible to diseases, as a single disease can wipe out the entire crop.
Step 5
Devise a method to find the optimum pH of an enzyme that breaks down starch.
Answer
- Prepare a range of buffer solutions at different pH values (e.g., pH 5, 6, 7, 8, 9).
- In separate test tubes, mix equal volumes of starch solution and each buffer solution.
- Add a fixed amount of enzyme solution to each test tube and incubate at a specific temperature.
- After a set time, use iodine solution to test for the presence of starch. The change in color will indicate how much starch has been broken down.
- The optimum pH is the one where the blue-black color persists the longest, indicating the least starch is remaining.
Step 6
Explain why this enzyme would not work at pH 10.
Answer
This enzyme would not work at pH 10 because enzymes have an optimal pH range in which they function best. At pH 10, the environment is too alkaline, which can denature the enzyme, affecting its active site and preventing it from binding to the starch substrate.