The examples of positive feedback loops are as follows:
- contractions during the process of giving birth
- Blood clotting
<h3>WHAT IS POSITIVE FEEDBACK LOOP:</h3>
- Positive feedback loop is that in which a change in a given direction causes additional change in that same direction.
- The contractions during the process of giving birth is an example of positive feedback loop because the contractions further stretch the walls and continues until birthing occurs.
- Also, the clotting of blood causes the stoppage of blood flow.
Therefore, the examples of positive feedback loops are as follows:
- contractions during the process of giving birth
- Blood clotting
Learn more about positive feedback loops at: brainly.com/question/11312580
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:
They used radioactive labeling techniques to build two different types of phage.
Explanation:
In 1952, a set of experiments were carried out by American biochemists Alfred D. Hershey (1908-1997) and Martha Chase. They prepared two separate virus samples, one contained DNA labeled with a radioactive isotope and the other contained protein labeled with a different radioactive isotope. They grew the two types of viruses separately, infected bacteria with the two sets of phages and analyzed the bacteria for radioactivity. From the results obtained, Hershey and Chase concluded that the viral genetic material was DNA and not protein, reinforcing the observations previously made by Avery.
None of them.
I'm assuming that you left off an option. a prokaryotic cell is a single-celled organism, generally a bacteria. an example would be e-coli.
Answer: - Predict an unknown genotype of a purebred dominant plant.
Explanation:
The genetic make up of the organism is called as the genotype. It describes the form of genes or allelic forms present in the organism. A test cross is used to determine the genotype of the organism. In this cross the organism with the unknown genotype is done with that of the organism with the known genotype. It also determines the fact that the organism is either homozygous dominant or hetrozygous.
On the basis of the above description, Predict an unknown genotype of a purebred dominant plant.
