Answer:
B. introns; exons
Explanation:
Related genes from different organism usually translate to proteins of indispensable functions. This means that the proteins must be similar in terms of amino acids produced. Therefore the coding region must be highly conserved. These can be found in the introns. Conversely, exons are not a part of the coding sequence and therefore not required for translation. These sequences may be less conserved.
The correct answer is small hydrophobic molecules.
The smaller the molecule and the more hydrophobic, or nonpolar, it is, the more rapidly it will diffuse across a membrane. It is because of the composition of membrane (lipid bilayer). By contrast, membrane is highly impermeable to charged molecules (ions), no matter how small they are.
Layer c is the oldest and then it’s b and a
that's all wrong the real answer is b.99.3
