Home > Subjects > Biology > Level 3 > 3.3 Gene expression > Key tips
- Subject: Biology
- AS: AS90715
- Level: 3
- Credits: 4
- External
Biology 3.3 Describe the role of DNA in relation to gene expression
Key tips
- Understand the difference between a biological concept and a biological process.
- When answering questions (especially resource-based questions), make sure your answers are specific instead of general. Refer to information given in the questions, and justify your comments.
- Check your work for mistakes, for example, transcribed RNA sequence.
- The language for this subject is specific, so you must learn the relevant terms and definitions.
Terms include: gene expression, genetic code, transcription, translation, codons, nucleotides, redundancy, phenotypic outcome, biotechnology context, protein synthesis, nucleotides, mutations, allele, gene–gene interactions, Punnett squares, metabolic pathways, replication, gene expression, role of DNA, molecular components, enzyme, accurate copies, prokaryotes, feedback, repressors, inducers, enhancers, eukaryotes, allele interactions, dominance, incomplete dominance, co-dominance, multiple alleles, lethal alleles, linkage, gene–gene transactions, epistasis, collaboration, polygenes, pleiotropy, mutations – gene and chromosomal, and metabolic pathways.
- Use correct terminology and spelling.
- Attempt all questions as NCEA research is showing that students often get Achievement within an Excellence question just by expressing some relevant information.
- Get plenty of practice identifying the gametes involved and then doing the genetic crosses. Concentrate on dihybrid crosses, especially those involving epistasis.
- Epistasis does not just refer to supplementary genes as in the past, but to all situations where one feature is affected by two genes.
- Know the difference between a triplet, a codon, and an anticodon.
- Remember uracil replaces thymine in mRNA.
- Remember all the stop codons start with U (UGA UAG UAA).
- Watch out for a common misunderstanding about inbreeding and mutations. Remember that inbreeding does not cause mutations, but inbreeding gives an increased opportunity for prior and harmful recessive mutations to become homozygous and therefore be expressed.
