Answer:
The third choice.
Explanation:
It is near the Orion Arm and extremely far from the center. Although I don't know about the "tip"
Answer:
2. meiosis I only
Explanation:
During the zygotene stage of prophase-I of meiosis-I, homologous chromosomes synapse and are paired up. These paired homologous chromosomes are called bivalents. These paired homologous chromosomes align themselves at the equatorial plate of the cell during metaphase-I. Therefore, when observed through a microscope, cells are shown lined up two by two. During meiosis-II and mitosis, individual chromosomes with two sister chromatids are aligned at the cell's equator in metaphase.
Answer:
A. The chromatin near cis-regulatory sequences will be more closed and there will be less transcription.
Explanation:
In the presence of histones, the cis-regulatory sequences of DNA like promoter, enhancers etc. are not exposed. The function of the histone acetyltransferases (HATS) is to cause chromosome decondensation i.e. removal of histones from the DNA so that transcription of the DNA could occur. Histone acetyltransferases (HATS) cause acetylation of lysine amino acid of the histone proteins. Acetyl group is negatively charged so the acetylation of histone proteins leads to the removal of their positive charge which ultimately leads to the decrease in the interaction between N terminal of histones and negatively charged phosphate group of the DNA molecule. As soon as histones are removed from the DNA where cis-regulatory sequences are located, the DNA becomes accessible for transcription.
But here a drug has been added which blocks the activity of histone acetyltransferases (HATS) in cancer cells. So it is quite evident that in these cells, histones will not get removed from the cis-regulatory sequences of DNA so the DNA will be more closer or tightly packed as a result of which less transcription will occur.
Answer:
As a cell grows bigger, its internal volume enlarges and the cell membrane expands. Unfortunately, the volume increases more rapidly than does the surface area, and so the relative amount of surface area available to pass materials to a unit volume of the cell steadily decreases.