Achievement criteriaThe level of achievement that you will reach is decided by the way you answer each question. The key words are demonstrate understanding, in-depth understanding, comprehensive understanding of biological ideas relating to genetic variation. From your answers the assessor will assess your understanding of the topics of the achievement standard.

AchievementDemonstrate understanding of biological ideas relating to genetic variation. This involves recognising, naming, drawing, giving characteristics of, or an account of genetic variation.
Make sure you can describe:
  • how DNA carries instructions to the next generation
  • the link between DNA and phenotype
  • the differences between a chromosome, DNA and a gene
  • the relationship between genes and alleles
  • the link between genotype and phenotype
  • how chromosomes exist in pairs
  • how individuals inherit two copies of most genes
  • the importance of having different alleles of a gene
  • how mutations form new alleles
  • how meiosis produces gametes
  • how sexual reproduction produces genetic variation between individuals within a group of living organisms
  • the possible genotypes, and phenotype ratios of a simple monohybrid cross showing complete dominance
  • the possible genotypes, and phenotype ratios of a simple monohybrid cross showing sex determination
  • outcomes of a simple monohybrid cross using a Punnett square
  • genotype and phenotype outcomes of a simple monohybrid cross shown in a pedigree chart
  • inheritable variation that exists within a group of living things
  • non-inheritable variation that exists within a group of living things
  • how variation in phenotype within a group of living things gives differing rate of survival
  • the advantages and disadvantages of sexual reproduction
  • describe the specialised terms outlined in the subject content.
Achievement with MeritDemonstrate in-depth understanding of biological ideas relating to genetic variation. This involves explaining how or why genetic variation occurs.
Make sure you can explain:
  • the importance of DNA as the molecule carrying instructions for life to the next generation
  • how DNA determines phenotype
  • the relationship between a chromosome, DNA and a gene
  • the importance of having different alleles of a gene
  • how genotype determines phenotype
  • why chromosomes exist in pairs - one from each parent
  • why individuals inherit two copies of most genes - gives more genetic variation
  • how alleles of a gene differ – the order of bases in the DNA
  • how changes in the DNA (mutations) may or may not form a new alleles
  • how meiosis produces gametes with genetic variation
  • how meiosis and fertilisation produce genetic variation between parents and offspring
  • the reasons for the possible genotype, and phenotype ratio of a simple monohybrid cross showing complete dominance
  • the reasons for the possible genotypes, and phenotype ratios of a simple monohybrid cross showing sex determination
  • how variation in phenotype within a group of living things gives differing rate of survival
  • how variation within a group of living things is important in a changing environment such as pest infestation, disease, drought or flood
  • reasons for the advantages and disadvantages of sexual reproduction
Achievement with ExcellenceDemonstrate comprehensive understanding of biological ideas relating to genetic variation.
This involves linking biological ideas about genetic variation. It may involve explaining, elaborating, applying, justifying, relating, evaluating, comparing and contrasting, or analysing.
Make sure you can:
  • describe and explain the ideas listed above for achieved and merit
  • use linking words and phrases, such as ‘because’, ‘this means that’, ‘whereas. ‘however;’ when comparing and contrasting, discussing, elaborating etc.
  • show you understand that probability outcomes indicated in Punnett squares are dependent on chance and effected by sample sizes
  • demonstrate an understanding of chromosome numbers and genetic variation related to meiosis and sexual reproduction.