Answer:
Dehydration
Explanation:
Dehydration is the condition of the body which involves the loss of body fluid compared to the amount of water the body gets. Water is an important constituent of the human body making up to about two-third of the body. The normal body metabolism is affected when the amount of water in the body drops below the required level of water necessary for optimal functioning of the body.
Athletes usually suffer from dehydration, most especially long distance runners, as they tend to lose a lot of body fluid through sweating while the body tries to regulate the body temperature during the race. When the body is dehydrated, the heart works harder to pump blood to various parts of the body leading to loss of strength of the muscles.
Common signs a dehydrated person shows include feeling tired and lightheaded, loss of body weight etc.
Answer:
a substituted derivative of purine, especially the bases adenine and guanine present in DNA.
a colorless crystalline compound with basic properties, forming uric acid on oxidation.
The correct answer is microbiology.
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Microbiology is the branch of science that study microorganism. It contains a few sub-disciplines including virology (study viruses), parasitology (study parasites), mycology (study fungi) and bacteriology (study bacteria). Studied microorganism might be unicellular (one cell), multicellular (cell colony), or acellular (without cells).</span>
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.
