Matter can be broken down into two categories: pure substances<span> and </span>mixtures.Pure substances<span> are further broken down into elements and compounds. ... A chemical </span>substance<span> is composed of one type of atom or molecule. A </span>mixture<span> is composed of different types of atoms or molecules that are not chemically bonded</span>
Melanin provides pigmentation to the skin and it also provides UV ray protection (which is its role in the epidermis).
mostly collagen and some calcium phosphate
3.13 x 10 ^9
This is because only 1 number is front of the decimal and 2 numbers should be after
A dichotomous key is defined as a biological tool for identifying unknown organisms to a particular taxonomic level. It is constructed with many levels and series of couplets.
So, by observing the given dichotomous key, it is concluded that the correct answer is Option A- Organism X and Z have at least one observable trait in common in this dichotomous key.
