Question

question 1
how does dna methylation impact gene expression?
increases gene expression
can block or increase gene expression
blocks gene expression
no impact
question 2
how does histone modification change gene expression?
histone modifications do not change gene expression
histone modifications decrease transcription
histone modifications can increase or decrease gene expression
histone modifications increase transcription
question 3
which statement best explains why nerve and muscle cells can be so different despite having the same dna?
they have different numbers of mitochondria
these cells express different genes
only one of these cells have histones
these cells have different environments

Explanation:

• DNA methylation typically blocks gene expression by preventing transcription factors from binding to DNA.
• Histone modifications such as acetylation, methylation etc. can either increase or decrease gene expression by altering the chromatin structure and accessibility to transcription - related machinery.
• Nerve and muscle cells have the same DNA but are different because they express different sets of genes through processes like differential gene regulation.

Answer:

• QUESTION 1: C. Blocks gene expression
• QUESTION 2: C. Histone modifications can increase or decrease gene expression
• QUESTION 3: B. These cells express different genes