The correct answers are:
- Methylation of histone tails in chromatin can promote condensation of the chromatin.
- DNA is not transcribed when chromatin is packaged tightly in a condensed form.
- Acetylation of histone tails is a reversible process.
- Some forms of chromatin modification can be passed on to future generations of cells.
- Acetylation of histone tails in chromatin allows access to DNA for transcription.
Histone modifications are post-translational modifications of histone protein that can affect gene expression by altering chromatin structure or recruiting histone modifiers.The most common modifications are methylation, phosphorylation, acetylation and ubiquitylation. All of them affect the binding affinity between histones and DNA and thus loosening (gene activation) or tightening (gene repression) the condensed DNA.
Histone methylation is a transfer of methyl group by histone methyltransferases to lysine or arginine amino acid of protein. Effect of methylation depends on the type of protein that is modified. Demethylation is the reverse process.
Histone acetylation is the process of adding of an acetyl group(by histone acetyltransferases) to histone proteins and it can also activate or inhibit the gene expression. Deacetilation is reverse process.
<em><u>ANSWER</u></em>
ln most cases inorder to obtain the mass of a liquid one measures the mass of both the liquid and the container it is in and after wards remeasures the container alone and later subtract the mass of the container alone from the total mass of both the container and the liquid
<span>Proteins have a very high molecular weight and cannot be present as macro molecules in the glomerular blood. Before even reaching the blood, they are well masticated and processed to simple amino acids and other nitrogenous compounds like urea, uric acid etc. (in the digestive system itself). They are eliminated from the body while glomerular filtration through urine. The glomerular blood thus becomes free from such compounds before leaving the kidney.</span>
False. parasites infect and feed
