Polydactyly is an inherited condition that causes a person to have extra fingers or toes. It is caused by a dominant allele.
The family tree shows the inheritance of polydactyly in a family.
Complete the table using the information in the family tree:
- Number of people who have polydactyly: 5
- Number of people who are homozygous recessive for this gene: ___________
- Number of people who are heterozygous for this gene: ___________
Person X and Person Y are expecting another child. Complete a genetic diagram (using DDD for the dominant allele and ddd for the recessive allele) to find the probability that this child will have polydactyly.
Polydactyly is a genetic condition. Give one reason why genetic conditions are classified as non-communicable.
Some genetic conditions are caused by abnormal structural proteins produced in body tissues. Scientists are working on treatments using artificial monoclonal antibodies designed to target these specific proteins.
Explain why the body does not naturally produce its own antibodies against such abnormal proteins produced by its own cells.
Suggest two reasons why some people are opposed to testing new medicines on animals.