Answer:
The DNA strands are not free in the nucleus, but forming a compact structure called chromatin along special proteins, known as histones. The chromatin structure has an important role in gene expression, as the level of compaction and the histone modification act as signals for the transcription machinery
In order to be transcribed, different areas in the genome need to unfold from the histone proteins, so the RNA polymerase can access the DNA.
That means, <u>that DNA sequences that transcribe at high rate, are more often unfold from the histones, and more exposed to other proteins to bind them. Particularly, those areas are more sensitive to the attack of endonucleases, such as DNAse I.</u>
As a consequence, an assay of DNAse I digestion can be used to identify highly sensitive or resistant to DNAse cleavage areas in the genome, and therefore serve as an insight to which sequences are more and less transcriptionally active.
Answer:
The bright color of butterflies is a discouraging factor for its prey
Explanation:
Butterflies and caterpillars are easily visible to its prey but still they do not eat any of them. This can be because of two factors –
a) The bright color of these organisms might be a factor that makes them uninteresting (intending to be tasteless etc.) for their prey
b) The bright color might be a signal to the bird indicating in advance of any harm associated with the butterflies/caterpillar feeding.
Hence , instead the Monarch butterflies have brightly colored orange wings with black patterns on them, making them easily visible to birds, the birds rarely eat the monarchs
Answer:
Prezygotic barriers:
1. Habitat isolation
2. Behavioral isolation
Explanation:
Pre-zygotic barriers are the barriers which do not allow the formation of the zygote in the organisms.
The two mechanisms of the pre-zygotic barriers are the:
1. Habitat isolation: the Flycatchers do not share the same habitat which is also mentioned in the question that they live on different islands.
2. The behavioural isolation: the Flycatchers could have evolved the different mating rituals as a result of which the could not interbreed.
Thus, Habitat isolation and Behavioral isolation are correct.
It is called the transition state species. They are a bit of a hybrid, or a halfway point between the structure of the reactants' structures and products' structures. Bonds in the transition state can be partially formed and are represented by a dotted line.
Answer:
the answer to this question is the light colour
