Answer:
The evidence suggests that these chloroplast organelles were also once free-living bacteria. The endosymbiotic event that generated mitochondria must have happened early in the history of eukaryotes, because all eukaryotes have them
Explanation:
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If you didn't know already, trisomy 21 is also known as Down Syndrome. It is caused by error in the cell division which is called nondisjunction. It leaves a sperm or egg cell with an extra copy of chromosome 21 before or after conception.
Answer: 25% assuming the parents are both Aa
Explanation:
Two AA parents - 0%
Two Aa parents - 25%
Two aa parents - 100%
