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:
The gluten free diet is helpful for the people that are sensitive to food with gluten it which occurs due to the celiac disease. It was originally meant for the such people but it becomes a new fad. However, there is no compelling evidence to support that gluten free diet helps in health improvements n non sensitive people.
In other hand there are majority of doctors are against the use of gluten free diet is not good for various body organs like heart. A study concluded that there are lower risk of heart disease in people take more gluten. Doctors and various study suggests that people with no celiac disease should not avoid gluten.
1. Rainforests only cover around 2 percent the total surface area of the Earth, but really about 50 percent of the plants and animals on the earth live in the rainforest.
2. There are two different types of rainforests, and they include both temperate and tropical. The tropical rainforests are the ones that are most commonly found around the world.
3. A fifth of our fresh water is found in tropical rainforests, the Amazon Basin to be exact.
4. Within four square miles of tropical rainforest, you will find 1500 flowering plant species, 750 types of trees, and many of these plants can be helpful in combating cancer.
5. Rainforests are threatened each and every day, especially by practices such as agriculture, ranching, logging and mining.
Hope this helps!
~Starr
Because there are too many sex chromosomes I think
