This can be because of their genetics. The siblings may not have inherited their parents looks, but maybe they inherited their grandparents looks, or even their aunts looks. This is all due to genetics. It's sort of the same thing, when two caucasian parents have an african-american child. That would be because somewhere along the family tree someone was african-american.
Anyways, I hope this helps!
Answer:
Transpiration through stomata
The answer is Mercury! Hope this helps
The innate responses that animals have in their system is called as reflex. This can be practiced to perfection depending on your preferred style - whether you want it for defense mechanisms, or even on activities that usually uses the mind. All living creatures have this mechanism. The answer should be B.