Reproduction 1

1) Cystic fibrosis is an inherited condition which causes the body to produce thick and sticky mucus which clogs the lungs and pancreas. Patients must take many medications and undergo physical therapy every day to help keep them alive. Cystic fibrosis is caused by a recessive allele. Explain what is meant by a recessive allele 2 Marks

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2) Two heterozygous parents for cystic fibrosis are planning on having a child. Complete the genetic diagram and predict the probability of their child having cystic fibrosis. Use the letter C to represent the normal dominant allele, and the letter c to represent the recessive cystic fibrosis allele 3 Marks

3) Due to severe complications associated with cystic fibrosis, some parents choose to undergo embryo screening, to ensure that their future child will not have cystic fibrosis. Evaluate some of the economic, social and ethical issues associated with embryo screening for cystic fibrosis 4 Marks

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4) The parental gametes are produced by a process known as meiosis. Outline the process of meiosis 4 Marks

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5) How many chromosomes are there in a human gamete produced by meiosis? 1 Marks

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6) Developing new treatments for cystic fibrosis has been greatly helped by the sequencing of the human genome in 2001. Explain how the sequencing of the human genome has helped scientists to understand cystic fibrosis 2 Marks

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