If two siblings share the same parents, they should share 50 per cent of their mother's chromosomes, and 50 per cent of their father's chromosomes. Additionally, each organism including human beings, has a unique number of chromosomes.
8 months ago
Last edited at 5:37AM on 4/26/2013
Everyone has 46 chromosomes. 23 of these come from their mom, 23 from their dad. However, a pair of siblings are very unlikely to get the same chromosomes, since they'll probably get a different set from their mother then their sibling did. Look at it like this: Your mother has three chromosomes, a blue one, a red one, and a green one. You get a blue one, and a green one. Your sibling gets the green one, and the red one. You share 1 chromosome, but each have a different one besides that. Thus you look different. Makes sense?