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Living Environment Regents June 2008 Question 22 |
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Thursday, 23 April 2009 06:29 |
Differentiation & growth
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination. In humans, it is called an embryo from the moment of implantation until the end of the 8th week, where after it is instead called a fetus. The Embryo grows by mitosis which represents division of the cells for growth.
Mitosis is the process in which a eukaryotic cell separates the chromosomes in its cell nucleus, into two identical sets in two daughter nuclei.[1] It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two daughter cells containing roughly equal shares of these cellular components. Mitosis and cytokinesis together define the mitotic (M) phase of the cell cycle - the division of the mother cell into two daughter cells, genetically identical to each other and to their parent cell.
Hence the other 3 options do not hold good for the development of Embryo.
Correct Answer: Option 2
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