Ring species.
When there are neighbouring populations that can interbreed with each other while only two of those populations cannot breed between them, we are standing before a ring species. In the case of Larus gulls what is observed is that several of these species can interbreed, but it comes to two of them that are incompatible - they are probably to<span> distantly related to interbreed. It is considered, that this species may be connected to each other in a line of derivation and is both ends on that line that are incompatible.</span>
Answer:
Keep its body temperature constant regardless of the environment. its A
Answer:
index fossils are important for index fossils because
they use them to match up rock layers in certain locations
that may be far apart!
So I think it's C
The enzyme’s active site binds to the substrate. Since enzymes are proteins, this site is composed of a unique combination of amino acid residues (side chains or R groups). Each amino acid residue can be large or small; weakly acidic or basic; hydrophilic or hydrophobic; and positively-charged, negatively-charged, or neutral. The positions, sequences, structures, and properties of these residues create a very specific chemical environment within the active site. A specific chemical substrate matches this site like a jigsaw puzzle piece and makes the enzyme specific to its substrate.