Back to the full dot-point answer
TASBiologyQuick questions
Unit 3: Heredity and Continuity of Life
Quick questions on DNA and Gene Expression - TCE Biology (Tasmania)
3short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What is translation?Show answer
Translation reads the mRNA and builds a polypeptide. The genetic code is read in groups of three bases called codons. Each codon specifies one amino acid, and the code is described as degenerate because most amino acids are coded for by more than one codon. There is a start codon (AUG) and there are stop codons that end translation.
What is gene regulation?Show answer
Cells do not express every gene all the time. Regulation controls which genes are switched on, when, and how strongly, which is why a nerve cell and a skin cell carry the same DNA but behave differently. Regulatory proteins called transcription factors bind to control regions of DNA and either promote or block RNA polymerase. Environmental signals, hormones, and the cell type all influence which genes are active.
What are mutations?Show answer
A mutation is a change in the DNA base sequence. A substitution swaps one base for another and may be silent (no change to the amino acid), missense (a different amino acid), or nonsense (creates an early stop codon). Insertions or deletions that are not multiples of three cause a frameshift, which shifts how every following codon is read and usually disrupts the whole protein. Mutations are the ultimate source of new alleles and therefore of variation.
Have a question we have not covered?
This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.