Technically, they can but you don't have to be related because you can have things in common with another person with are personality traits , and if they have different skin colors it doesn't matter , and you can still have many traits in common , because my sister is darker than me a lot but we still share same traits.
I don't know what the picture is but I had a question like this on my packet and I saw a <span>sugar with two, and not three, oxygen atoms</span>
Cell membraine i hope that help
