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.
The scientist that discovered cells by observing cork with a homemade microscope would be Robert Hooke.
Answer:
B. Both mussels and barnacles live in the tidal ecosystems.
Explanation:
Mussels are <u>small bivalve molluscs that are adapted to both marine and freshwater ecosystems</u>. Barnacles, on the other hand, <u>are arthropods that are adapted to marine ecosystems. However, both are adapted to shallow and </u><u>tidal</u><u> zones</u>.
Both organisms are small and have the capacity to live in tidal ecosystems where they thrive and play important ecological roles. For instance, barnacles are filtering organisms, which is extremely important for the food chain, and mussels filter out significant amounts of excess nutrients and metals, that is, they make the water more suitable and clean for organisms to live.
As they are both adapted to tidal ecosystems, this would be an example of an adaptation that allows similar species, in this case mussels and barnacles, to live in the same environment.
The answer would be false because Proprioceptive neuromuscular facilitation is a mode of stretching that uses reflexes and neuromuscular principles to relax the muscles being stretched while ballistic stretching is exercise <span>conducted with jolting, rapid, and bouncy movements.</span>
