The following sentences describe chromatin structure and how altering chromatin
ID: 175121 • Letter: T
Question
The following sentences describe chromatin structure and how altering chromatin structure can affect gene expression. Complete each sentence using the words provided. In some cells, DNA combines with proteins to form a substance called chromatin. The lowest level of chromatin structure consists of DNA wrapped twice around a group of histones to form a(n) nucleosome. The formation of nucleosomes may block the binding of transcription factors and RNA polymerase II to the The structure of chromatin can be modified by altering either the DNA or the attached to DNA. Large chromatin-remodeling complexes alter the structure of chromatin in order to make the DNA accessible to regulatory proteins which, in turn, affect gene expression. In vertebrates, methylation of ensures that once a gene is turned off, it stays off. The of histones is correlated with tighter coiling of the DNA and inactive regions of chromatin. The of histones tends to loosen the coiling of DNA, making it more accessible for transcription. Chromatin is present in cells only. Chromatin that contains highly condensed DNA which is not being expressed is called Chromatin that contains loosely coiled DNA, which is accessible for transcription, is called Tighter coiling of the chromatin makes the DNA accessible for transcription.Explanation / Answer
In some cells DNA combines with proteins to form chromatin
The lowest level of chromatin structure consists of DNA wrapped twice arouns a group of histones to form a neucleosome
The formation of nucleosomes may block the binding of the transcription factors and RNA polymerase II to the operator
The structure of the chromatin may be modified by altering the either the DNA or the histones attached to the DNA
Large chromatin remodeling complexes alter the structure of chromatin inorder to make the DNA euchromatin accessible to regulatory proteins, which inturn affect gene expression
In vertebrates DNA methylation of ensures that once a gene is turned off it remains off.
The acetylation of histones is correlated with tighter coiling of the DNA and inactive regions of the chromatin
The phosphorylation of histones tends to loosen the coiling of DNA making it more accessible to transcription (Bannister, 2011).
Chromatin is present in animal cells only
Chromatin that contains highly coiled DNA not being expressed is called heterochromatin.
Chromatin that contains loosely coiled DNA that is being expressed is called Euchromatin
Tighter coiling of the chromatin makes the DNA less accessible to transcription