Inherited Disorders (GCSE Biology)

What is the best description of a dominant allele?

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

Which term describes small differences between individuals of the same species that are not caused by genes but by the environment?

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?

In a Punnett square cross between two heterozygous parents (Aa × Aa) for a recessive disorder, what proportion of their children will be carriers (heterozygous)?

Which term describes a person who carries a recessive disease allele but does not show the disease symptoms?

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

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

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

Polydactyly (extra fingers or toes) is caused by a dominant allele. Which genotype would result in a person showing the polydactyly trait?

What term describes a permanent change in the DNA sequence that can create a new allele?