Surface tension is the property of water which allows for some lightweight insects to walk on top of a pond and not fall in. The molecules of water are held together by cohesive forces. The molecules of water present below the surface experience this cohesive force from all the directions, whereas the water molecules present on the surface experience a downward pull, as the force is not balanced. This leads to the concaving of the water surface inside a small tube.
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.
Type of symmetry in which body parts are arranged in a circle around a central point is called radial symmetry.
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This type of symmetry is characteristic for the sessile animals like Cnidaria and Echinodermata. Organisms with radial symmetry have no left or right sides, they have a top and a bottom surface, or a front and a back.</span>
Answer: 100% short hair
Explanation: there will 50% homozygous short hair (HH) and 50% heterozygous short hair (Hh).
Check out the punnet square down below to see how it’s done.
Answer:
Nutrient-rich blood flows into the liver from the intestines through the hepatic portal vein.
