Mitosis begins with prophase, during which chromosomes recruit condensin and begin to undergo a condensation process that will continue until metaphase. In most species, cohesin is largely removed from the arms of the sister chromatids during prophase, allowing the individual sister chromatids to be resolved.
Prometaphase begins with the abrupt fragmentation of the nuclear envelope into many small vesicles that will eventually be divided between the future daughter cells. The breakdown of the nuclear membrane is an essential step for spindle assembly.
Next, chromosomes assume their most compacted state during metaphase, when the centromeres of all the cell's chromosomes line up at the equator of the spindle. Metaphase is particularly useful in cytogenetics, because chromosomes can be most easily visualized at this stage. Furthermore, cells can be experimentally arrested at metaphase with mitotic poisons such as colchicine.
The progression of cells from metaphase into anaphase is marked by the abrupt separation of sister chromatids. A major reason for chromatid separation is the precipitous degradation of the cohesin molecules joining the sister chromatids by the protease separase.
Mitosis ends with telophase, or the stage at which the chromosomes reach the poles. The nuclear membrane then reforms, and the chromosomes begin to decondense into their interphase conformations. Telophase is followed by cytokinesis, or the division of the cytoplasm into two daughter cells. The daughter cells that result from this process have identical genetic compositions.
A. True
variation of reproduction produces diverse life forms and allows organisms to evolve complex characteristics over billions of years.
Answer:
<em>1. A low- pressure weather system can cause a thunderstorm to develop. </em>
<em>2.Thunder is caused by lightning. When a lightning bolt travels from the cloud to the ground it creates a channel. Once the light is gone the air collapses back in and creates a sound wave that we hear as thunder.</em>
<em>3. One condition that is necessary for a thunderstorm include warm air and moisture.</em>
<em>4. The dangers of a blizzard include getting lost in the snow and freezing to death.</em>
<em>5. In my opinion, a hurricane would be the most difficult storm to face because hurricanes can severely impact your life due to their damage. For example,winds can damage houses, trees, and any other property. Even if your home is safe, flooding aftermath can occur. When homes are destroyed, people may have to rebuild homes and towns.</em>
Answer:
The answer is D
A is cell division, B is some stage of pregnancy, and C is DNA replication.
