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.
Answer:
Option (D)
Explanation:
The tropical rain forest and tropical dry forest lies on the tropical regions of both the hemisphere. These are the regions on and around the tropic of cancer and tropic of capricorn. In the tropical rain forest, the rate of precipitation is higher than the rate of evapo-transpiration, so the temperature remains relatively cooler. Whereas, in the tropical dry forest, the rate of evapo-transpiration is more than the rate of precipitation, as a result of which the temperature remains comparatively high.
The tropical dry forest is very good for agricultural purpose, as it contains nutrient rich soil. So it has been destroyed to a greater extent for agricultural use, grazing of animals.
Whereas, the tropical rain forest is not suitable for the agricultural use because the soil here are affected by the rainfall, that washes away the nutrients, making the soil less fertile.
Thus the correct answer is option (D).
<span>This classification system model was based on principles developed by Swedish scientist Carolus Linnaeus, whose hierarchical system groups organisms based on common physical characteristics. Taxonomy is a hierarchical system for classifying and identifying organisms. Carolus Linnaeus developed those principles in the 18th century. In 1990, Three-domain system was developed by Carl Woese, an American microbiologist and physicist. The three-domain system divides cellular life forms into archaea, bacteria, and eukaryote domains and each domain can be further divided into kingdoms, phyla, classes, and so forth so it changes every year...</span>
Answer:
diverging plate boundaries
Explanation:
Most volcanoes occur along diverging plate boundaries, such as the mid-ocean ridge, or in subduction zones around the edges of oceans.
