Inherited Disorders (GCSE Biology)

Haemophilia is an X-linked recessive disorder. Which child of a carrier mother and an unaffected father is most likely to have haemophilia?

Carrier screening can identify people who carry recessive disease alleles. What is a main benefit of offering carrier screening to couples planning a family?

Which process explains how populations become better suited to their environment over many generations due to inherited differences?

Sickle cell disease is caused by a recessive allele. Heterozygous individuals (carriers) have some resistance to malaria. What evolutionary concept explains why the sickle cell allele remains in some populations?

Which technique produces genetically identical plants quickly from a single parent plant and is often used to preserve plants with desirable traits?

What does it mean if an inherited disorder shows variable expressivity?

Which of the following is an ethical concern commonly raised about genetic screening and testing for inherited disorders?

A person inherits two alleles for each gene, one from each parent. What is the term for an individual who has two different alleles for a gene?

Preimplantation genetic diagnosis (PGD) can be used during IVF to test embryos for inherited disorders. What is one main advantage of PGD compared with testing during pregnancy?

Cystic fibrosis (CF) is caused by a faulty CFTR gene and is inherited as a recessive trait. If two carrier parents (both heterozygous) have a child, what is the probability the child will have CF?

What is the role of genetic counselling when a family has a known inherited disorder?