It takes the muscle time to act once it receives a response from the nerves. It also takes time for the electric impulse to pass between gaps in the nerves (synapses).<span />
Blood vessels that absorb strong pressure pulses contain more of elastic<span> tissues. These tissues are bundles of protein that can be found in extracellular matrix of connective tissue. These are produced by fibroblasts and smooth muscle cells found in arteries.
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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.
Answer:
similarities
Explanation:
The concept of reproductive isolation relates more toward genetic similarities to distinguish between species. The barriers prevent closely related species living in the same geographical area from interbreeding. They help to keep each species distinct from the others.
