Answer:
I think the answer is B.
Explanation:
I think this because they have these variations to better adapt to conditions in their environments.
A theory which is tested again and again and found to fit the facts and from the valid predictions may be made is then known as scientif ic law or priciples..
I think its false because gas exchange can happen in blood also
Answer:
The basal cell layer is the innermost layer of the epidermis, comprising the keratinocytes and melanocytes. Keratinocytes play an important role in providing skin structure and in functioning of the immune system. Melanin is a pigment produced by melanocytes, and is responsible for providing the skin color.
