Answer:
Large quantities of water molecules constantly move across cell membranes by simple diffusion, often facilitated by movement through membrane proteins, including aquaporins. In general, net movement of water into or out of cells is negligible. For example, it has been estimated that an amount of water equivalent to roughly 100 times the volume of the cell diffuses across the red blood cell membrane every second; the cell doesn't lose or gain water because equal amounts go in and out. There are, however, many cases in which net flow of water occurs across cell membranes and sheets of cells. An example of great importance to you is the secretion of and absorption of water in your small intestine. In such situations, water still moves across membranes by simple diffusion, but the process is important enough to warrant a distinct name - osmosis.
MAD (mitotic arrest deficient) are proteins related to spindle cell cycle checkpoint and it is important since they prevent the segregation of sister chromatids until all have bound to the spindle.
The cell cycle ensures the duplication of the genome and its distribution in daughter cells by passing through a coordinated and regulated sequence of events.
A series of checkpoints guarantee the orderly progression of the phases of cell division and the correct distribution of the duplicated genetic material in the daughter cells.
The checkpoints during mitosis are:
- At the end of stage G1 and before S.
- Before anaphase in mitosis.
- DNA damage checkpoints in G1, S or G2.
The checkpoint before anaphase in mitosis guarantees the separation of chromosomes, and operates by activating the Mad2 protein that prevents the degradation of segurin, until the conditions are appropriate.
That is, the Mad2 protein prevents the segregation of sister chromatids until they have all bound to the spindle.
Therefore, we can conclude that MAD (mitotic arrest deficient) are proteins related to spindle cell cycle checkpoint and it is important since they prevent the segregation of sister chromatids until all have bound to the spindle.
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<span>The answer is Due to heating of the air by the engine exhaust. Contrails are formed when the hot exhaust of the plane engines is rapidly cooled by the cold air in the upper atmosphere. The water vapor in the engine exhaust, formed in the combustion of fuel, freezes immediately to ice crystals due to the low pressure and -36oC temperatures in the 8000 m altitude in which the planes cruise. </span>
• Offspring are genetically identical to parent-asexual reproduction
Fungi reproduce asexually on different ways such as fragmentation, budding, or producing spores(asexual spores, which are produced by one parentand thus, genetically identical to that parent).
• Offspring genetically distinct-sexual reproduction
Sexual reproduction introduces genetic In fungi, there are two ways(two mating types):both mating types are present in the same mycelium (homothallic) or mycelia require two different mycelia (heterothallic).
