Answer:
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Explanation:
About 95 percent of the time, Down syndrome is caused by trisomy 21 — the person has three copies of chromosome 21, instead of the usual two copies, in all cells. This is caused by abnormal cell division during the development of the sperm cell or the egg cell.
Ur answer is number 2 i'm almost sure of i
The reproductive system is a group of sex organs that work together for the purpose of sexual reproduction. Hope this helped!
Explanation:
Naturalists began to focus on the variability of species; the emergence of paleontology with the concept of extinction further undermined static views of nature. In the early 19th century Jean-Baptiste Lamarck (1744–1829) proposed his theory of the transmutation of species, the first fully formed theory of evolution.
In classical Latin, though, evolution had first denoted the unrolling of a scroll, and by the early 17th century, the English word evolution was often applied to 'the process of unrolling, opening out, or revealing'. It is this aspect of its application which may have been behind Darwin's reluctance to use the term.
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