4.1.3 Gene Expression

Question 1

What is Gene Regulation

Answer 1

Gene Regulation is the process of controlling which genes are expresed by which cells, when they are expressed, and in what quantity

Question 2

What is the difference between constitutive genes and regulated genes

Answer 2

Constitutive genes are expressed continuously and require little to no regulation

Regulated genes are produced as required, in order to conserve cell energy. They are regulated through transcription factors (which are proteins that are produced by regulatory genes)

Question 3

Why is gene regulation important?

Answer 3

It is essential to cell differentiation and specialisation, so cells the only porduce gene products specifi to their role

E.g. insulin is only produced in the pancreatic cells and not everywhere thanks to regulation

Question 4

Where can gene regulation occur?

Answer 4

Pre- Transcription Stage ( access to a gene can be controlled by chromatin)

_*Transcription Stage* ( transcription factors are proteins that bind at a region prior to the start of a gene, controoling RNAP access)_

RNA processing Stage (introns and exons controlling different gene products)

Translation Stage (miRNA inhibit or prevent translation by binding to mRNA)

Post-translation stage (addition of chemical groups to protein)

Question 5

Explain how transcription and translation factors work

Question 6

What is the memorised QCAA definition of a gene?

Answer 6

Region/s of DNA that are made up of nucleotides; the molecular unit of heredity

Question 7

What is the memorised QCAA definition of a genome?

Answer 7

All the genetic material in the chromosomes of an organism, including its genes and DNA sequences