Module 6 - Part 1

Question 1

What is epigenetic?

Answer 1

Epi (above) + genetic
- changes in gene expression that DO NOT ARISE from changes in the DNA seq.
- helps determine which genes in your body get turned on/off
- plays a role in tissue-specific gene expression and thus tissue identity and func.

Question 2

Epigenetic movie analogy

Answer 2

Epigenetics = “directors” of gene expression
Genes = movie script (don’t change once finalized)
Transcription factors = actors

Question 3

Nucleosome

Answer 3

single unit of DNA wound around a core of histone proteins

Question 4

Chromatin

Answer 4

several repeating nucleosome units
- “beads on a string” (11nm): eu chromatin = transcriptionally active
- tightly packed fibre (30nm): heater chromatin = transcriptionally inactive

Question 5

Fun facts regarding DNA
(DNA is packaged into high order structures slide)

Answer 5

• DNA from all 23 chromosome pairs aligned from end-to-end from a single cell = 2m
• average nucleus size for a mammalian cell = 5-6 um

Question 6

Genomic imprinting

Answer 6

DNA methylation-mediation silencing of one parental allele; resulting in mono allelic gene expression

Question 7

What are mono allelic genes more susceptible to?

Answer 7

Deletion and mutations