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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 and then undergoes two rounds of division, resulting in four haploid cells. Each gamete contains half the number of chromosomes found in the original cell.
Step 3
Suggest why the triploid oysters are not able to reproduce.
Answer
Triploid oysters are not able to reproduce because they have an odd number of chromosome sets, which means that during meiosis, they cannot undergo proper chromosome pairing. The rearrangement of chromosomes leads to issues in the formation of viable gametes.
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 allocate energy for reproduction. All available energy can thus be directed towards growth and development, making them larger in size in a shorter period.
Step 5
Suggest two environmental factors which may be causing this reduction.
Answer
- Increased water temperatures due to global warming can negatively impact the survival of diploid oysters by creating unsuitable living conditions.
- Pollution from agricultural runoff may introduce harmful substances into the water, which can be toxic to oysters and detrimental to their growth and reproduction.
Step 6
Evaluate the production of triploid oysters for supermarkets and restaurants.
Answer
The production of triploid oysters offers both advantages and disadvantages. On one hand, triploid oysters can be sold throughout the year as they maintain a good taste. This could increase profits for supermarkets and restaurants. However, the use of the chemical cytochalasin B to produce these oysters raises concerns about health risks, as it has been linked to cancer in mice. Furthermore, the sustainability of triploid oyster farming may be questioned if they cannot reproduce and thus rely solely on continuous cultivation. Therefore, while triploid oysters can enhance market availability, potential health implications must be critically considered.