Answer: C. Homologous chromosomes are separated in meiosis but not in mitosis.
Explanation: There are two main types of division that take place in eukaryotic cells, mitosis, and meiosis. Mitosis is the type of division that is used for growth, repair, and replacement of tissues. Therefore it is not necessary that the cells have different chromosome numbers or are varied genetically in the daughter cells in the case of mitosis.
Meiosis is the division that takes place to form the gametes for sexual reproduction. It is important in the first stages of meiosis I, to introduce variation and to halve the chromosome number.
Chromosomes numbers are halved (from 46 to 23) during meiosis I because the gametes (sperm and egg) come together and fuse during fertilization to form a zygote. When this fusion occurs (23 from the zygote and 23 from the egg), the chromosome number needs to be returned to that of the parent cell (46).
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Genetic variation is introduced during synapsis which only occurs in meiosis, not mitosis. Homologs exchange genetic information during crossing over of synapsis. Entire chromosomes also separate during meiosis I.
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At the end of meiosis, four genetically unique cells are produced with half the number of chromosomes as the parent cell (23 cromosomes) . After the process of mitosis is completed, two cells genetically identical to each pther are produced and have the same number of chromosomes as the parent cell (46 cromosomes).
Genetic variation is actually important because of changing environmental conditions.
Answer:
Positive feedback system increases temperature of the earth surface which is good in a number of ways.
Explanation: For example, due to increase in the temperature of earth surface, melting of ice occurs in the mountainous area of the world. This stored form of water is changed into liquid form and flows down through streams and used by plants and animals. But more increase in temperature causes rise of sea level which is not good for areas near the sea.
B is the answer hope i can help
Blood clots form when platelets and plasma proteins thicken to form a sort of solid mass. They can form from an injury, blood flowing slowly through your system, or even for no obvious reason.
