The anwser is true. Exposure to ultraviolet rays can cause skin cells to produce melanin which darkens the surface of your skin into a suntan.
All the spheres on earth overlap with each other so that any changes occur in one sphere may affect the other.
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The four spheres of earth are Land (the lithosphere), water (hydrosphere), air (atmosphere), living things (biosphere). The living organisms receive sunlight, heat, and gases from the atmosphere and water from the hydrosphere.
All these spheres are interlinked with one other and assembles in a single location at the time of overlapping. Life would not be there on earth if all these spheres do not interact or overlap with each other.
Examples of the earth overlapping is given below;
- Birds the living organism that flies in the air.
- Water flows through the soil on land.
- Evaporation of water into the atmosphere causes rain on the land.
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:
that the blood is mixed togthere and ant that they made a child
Explanation: