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:
D. Plasmids are nucleic acids which can pass on traits
Explanation:
A Nucleic acid is one of the four biomolecule polymers in living systems. It is made up of monomeric units called Nucleotides. RNA and DNA are the two nucleic acids in existence and they function in storage and expression of genetic information.
According to the question, a colony of bacteria that can break plastics were mixed with the colony that can't break plastics. The two different colonies engage plamids, which conferred the ability to break plastics to some of the colonies that previously couldn't. This tells us that the ability to break plastics in the certain bacteria colony is GENETIC.
If the trait is genetic, the plasmid must be a nucleic acid because of the ability to genetically pass on traits. Note that, a plasmid is an extra-chromosomal DNA (nucleic acid) capable of replicating on its own. Hence, plasmids are nucleic acids which can pass on traits.
Answer:
The right answer for the blank is cleavage.
Explanation:
After fertilization the next step is cleavage in which zygote divide mitotically. As the embryo move from oviduct down the fallopian tube it divide into two cell and then four cells. four cell embryo is known as blastomere.
Answer:
midbrain, medulla, and pons
Explanation:
The brainstem (also known as truncus encephali) is localized in the posterior part of the brain, in the base between cerebral hemispheres and the cervical cord. <em>It's divided into three parts, the midbrain or mesencephalon, the pons or mesencephalon, and the medulla oblongata also known as long medulla or myelencephalon.</em> <em>In the image I added you can see the brainstem structure.</em>
Some of the brainstem functions include the regulation of respiratory and cardiac function, thermoregulation, and other functions related to vision, sleep, etc.
I hope you find this information useful and interesting! Good luck!
