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.
Unlike natural selection, genetic drift does not depend on an allele's beneficial or harmful effects. Instead, drift changes allele frequencies purely by chance, as random subsets of individuals (and the gametes of those individuals) are sampled to produce the next generation.
I think the answer is C and D
Lactic fermentation occurs in many organisms, but only during a specific process known as anaerobic respiration. Muscles usually receive energy through a process known as cellular respiration[15], but when there is a lack of oxygen in the organism, muscles go through anaerobic respiration.
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RFLP, AmpFLP are the two techniques which is used to create DNA profile
Explanation:
<u>RFLP technique: </u> RFLP technique stands for “Restriction Fragment Length Polymorphism”. It is molecular method of genetic analysis which allows to identified based unique pattern of restriction enzyme where DNA is cutting in specific regions. It requires large amount of sample. The costing is very high
<u>AmpFLP: </u>The AmpFLP stands for amplified length polymorphism. It is PCR based tool. Firstly, it uses as restricted enzyme. It is cheaper than RFLP technique. It is used as genetic engineering
