Questions and Answers

Describe a chromosome mutation as a change in the chromosome number or structure, using Down’s syndrome as an example (47 chromosomes instead of 46)

Describe a gene mutation as a random change in the base sequence of DNA, using sickle cell anaemia as an example

Describe the determination of sex in humans (XX and XY chromosomes)

State that two identical homozygous individuals that breed together will be pure-breeding

Explain why observed ratios often differ from expected ratios, especially when there are small numbers of offspring

Use genetic diagrams, including Punnett squares, to predict the results of monohybrid crosses and calculate phenotypic ratios, limited to 1:1 and 3:1 ratios

Understand and use the terms: dominant, recessive, phenotype, genotype, homozygous and heterozygous

Define an allele as an alternative form of a gene

Describe inheritance as the transmission of genetic information from generation to generation

Describe that different sequences of amino acids give different shapes to protein molecules