Eukaryotic Gene Expression

Eukaryotes need to regulate their genes

• during cell specialization that occurs during development

• in order to maintain homeostasis

• both a and b

• neither a or b

Tags

NGSS.HS-LS1-3

NGSS.HS-LS1-4

Which of the following is a control element for eukaryotic genes? Select all that apply.

• promoter sequence

• silencer sequence

• enhancer sequence

• activator

One way to regulate the expression of a gene is to control the formation of mRNA. This is called ___ control.

• transcriptional

• translational

• post-transcriptional

• post-translational

Which of the following is/are similarities between prokaryotic and eukaryotic gene expression?

• both use proteins to interact with the DNA to control gene expression

• both have histones complexed with their DNA

• both separate the processes of transcription and translation spatially

• all of the above

___ are DNA sequences which are often located far from the genes they regulate in eukaryotes and are where transcription activators can bind.

• histones

• promotors

• enhancers

Chromatin remodeling complexes make temporary changes in the nucleosome to make DNA less tightly bound to the histone core. When DNA becomes loose, access to promoter sites by transcription factors are then allowed therefore resulting in protein formation and gene expression.

• False

• True

Which of the following help to turn genes on so that they are expressed (transcribed and translated)?

• a high level of condensation (coiling around histones)

• histone acetylation

• DNA methylation

• histone methylation

Which of the following are types of post-transcriptional control of genes in eukaryotes?

• alternative RNA splicing or processing

• gene silencing through RNA interference

• destruction of ubiquitin tagged proteins

• all of the above

Alternative RNA splicing involves

• removing introns and splicing the same exons together

• removing exons and splicing the same introns together

• removing introns and splicing different exons together

• removing exons and splicing different introns together

What is occurring in this diagram?

• This is an mRNA which is being replicated. Two exonucleases can now chop the ends of the sequences and degrade the mRNA strands.

• This is mRNA degradation. Endonuclease enzyme cuts the mRNA into two fragments. Two exonucleases can now hydrolyse at 3’ end or 5’ end.

• After the mRNA strand is cleaved into two different fragments by endonuclease, two enzymes attach to the ends, ligating the enzymes. This is so that they can attach to the surface of the cell which inactivates them.

• The mRNA eventually degrades naturally into two pieces. The sequences now become nonfunctional as they are disconnected