Answer:
Explanation:
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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.
<span>The light-dependent reactions for photosynthesis occur in the chloroplasts of the plant cell.</span>
Answer:
<u><em>Galapagos finches</em></u><u> have various beak sizes that make foraging for food more successful.</u>
Explanation:
Organisms evolve over time due to changes in their genome. These are pontaneous, and occur in DNA at random. These changes are called mutations and form alleles or different forms of a gene.
Over time within a population, the number alleles increase the variation of the population. These variants may confer specific traits within an individual, that may confer a biological advantage.
Thus, the trait may make the organisms more capable of obtaining food, shelter a mate etc. or ensure survival, i.e. they are able to pass on their genes to the next generation.
