Indicate true (T) and false (F) statements below regarding DNA methylation in humans. Your answer would be a four-letter string composed of letters T and F only, e.g. TTTF.
( ) Methylation of adenines is the most common DNA methylation in humans.
( ) Methylated cytosine can be accidentally deaminated to produce thymine, leading to a C-to-T transition.
( ) Cytosine methylation often occurs within a 5?-CG-3? sequence.
( ) Shortly after fertilization, a genome-wide wave of demethylation takes place.

Question

Indicate true (T) and false (F) statements below regarding DNA methylation in humans. Your answer would be a four-letter string composed of letters T and F only, e.g. TTTF.
( )	Methylation of adenines is the most common DNA methylation in humans.
( )	Methylated cytosine can be accidentally deaminated to produce thymine, leading to a C-to-T transition.
( )	Cytosine methylation often occurs within a 5?-CG-3? sequence.
( )	Shortly after fertilization, a genome-wide wave of demethylation takes place.

Quizplus · Accepted Answer

The most common DNA methylation in vertebrate DNA occurs on cytosine (C) nucleotides largely in the sequence 5?-CG-3?. The accidental deamination of the methylated cytosine can then potentially lead to a mutation. Shortly after fertilization in mammals, a genome-wide wave of cytosine demethylation takes place and the vast majority of methyl groups are lost from the DNA.

Indicate True (T) and False (F) Statements Below Regarding DNA