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Many people eat shellfish called oysters - AQA - GCSE Biology Combined Science - Question 7 - 2018 - Paper 2
Question 7
Many people eat shellfish called oysters. An oyster has 20 chromosomes in each body cell. Which arrangement of chromosomes will a male oyster have in each body cel... show full transcript
Worked Solution & Example Answer:Many people eat shellfish called oysters - AQA - GCSE Biology Combined Science - Question 7 - 2018 - Paper 2
Step 1
Step 2
Describe the type of cell division that produces gametes.
Answer
The type of cell division that produces gametes is called meiosis. During meiosis, the DNA is replicated, followed by two rounds of division, resulting in four genetically distinct haploid cells, each containing half the original amount of DNA.
Step 3
Suggest why the triploid oysters are not able to reproduce.
Answer
Triploid oysters are not able to reproduce because they have three sets of chromosomes. This means that they cannot undergo meiosis properly, as there are not equal pairs of chromosomes to segregate. As a result, gametes cannot form.
Step 4
Explain why the triploid oysters grow more quickly than the diploid oysters.
Answer
Triploid oysters grow more quickly than diploid oysters because they do not invest energy in reproduction. Since they are sterile, all their energy can go into growth and development, making them grow faster than diploid oysters, which need to allocate resources for gamete production.
Step 5
Suggest two environmental factors which may be causing this reduction.
Answer
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Rising temperatures of water: Increased temperatures can negatively affect the survival of oysters, impacting their growth and reproduction.
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Pollutants in the water: Pollutants may kill oysters or lead to diseases that reduce their populations.
Step 6
Evaluate the production of triploid oysters for supermarkets and restaurants.
Answer
The production of triploid oysters for supermarkets and restaurants has several advantages and disadvantages.
Advantages:
- Triploid oysters are available all year, meeting consumer demand, and contributing to the expansion of the oyster farming industry.
- They can be produced more cheaply than diploid oysters due to their faster growth rates, resulting in higher profit margins for farmers and suppliers.
Disadvantages:
- The use of cytochalasin B in the production of seed oysters raises safety concerns as it has been linked to cancer in mice, which could pose risks to human health.
- Dependence on triploid oysters may lead to a lack of biodiversity in oyster populations, making them susceptible to diseases and environmental changes.
In conclusion, while triploid oysters provide economic benefits, careful consideration of environmental and health implications is essential for sustainable seafood production.