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Time To Grow And Divide:
Not all cells divide into two daughter cells. For example, the alga Chlamydomonas divides into eight daughter cells. Some other algae and fungi divide into hundreds of daughter cells.Nonceffular, or Syncitial, Growth. Some kinds of alls can grow extensively without cell division. One group of microorganisms, the Mycetozoa, east as huge ameboid protoplasmic masses called plasmodia, which contain thousands of nuclei without cell membranes. Occasionally, fragments separate from the plasmodium, and these fragments can grow in size and their nuclei can divide. These noncellular multinuclear organisms or tissues are referred to as syncytial.When normal animal cells are cultivated on glass surfaces overlaid by a liquid nutrient medium, they grow and divide. The daughter cells can move away from each other by ameboid motion. When the cells are so numerous that their surfaces come into frequent contact, the population immediately stops growing. Experiments have shown that the contact between cells is responsible for the growth stoppage, a phenomenon described as contact inhibition.
Matotrophin (STH), ie anterior pituitary eneralized stimula-T, it is also known ssues; to be im-'ydrate metabo-various other bers; those that do not die take an increasingly long time to grow and divide. Eventually, the rates of cell death and of cell replacement become equal, and the population reaches a stationary level. In general, there are two reasons why a cell population stops increasing and growth is limited. First, the supply of an essential nutrient may become exhausted.
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