Topic 4.5: Gene Expression (HL) Questions

Define the term transcription factor.

Which list contains only environmental factors known to alter epigenetic marks?

What kind of molecule is a transcription factor?

Which change is an epigenetic change rather than a mutation?

State the stage of gene expression at which transcription factors act to control whether a gene is expressed.

Define the term epigenetic change.

At which stage is gene expression mainly controlled in a eukaryotic cell?

State the two processes that, together, make up the expression of a gene.

Which statement best describes an epigenetic change?

State what is meant by the term epigenetics.

State what is meant by an epigenetic mark.

What does it mean to say that a gene is 'expressed'?

Which change to a gene is normally reversible?

Expression of a gene is often measured from the amount of mRNA it produces. State the relationship between the amount of mRNA from a gene and how strongly that gene is expressed.

A change to a cell switches a gene off but leaves the DNA base sequence exactly as it was. What kind of change is this?

Which statement about epigenetic marks such as DNA methylation is correct?

A gene produces 60 units of mRNA in liver cells and 4 units of mRNA in skin cells. Both cell types contain the gene. What is the best conclusion?

The diagram shows the same stretch of DNA in two states. In the lower panel the gene is OFF. Which features of the lower panel explain why no mRNA is made? [Diagram: bio-gene-regulation]

Every cell in a multicellular organism is produced by mitosis from a single zygote, so all the cells contain identical DNA. Explain how cells with identical DNA can develop into different cell types with different structures and functions.

A mutation can change a protein's structure, but an epigenetic change does not. Why?