Photo receptors are attached to the retina and are most numerous specifically at the fovea
The amino acids are the building blocks of the proteins.
Explanation:
The amino acids are the organic molecules made up of a carboxylic group, an amino group and a carbon side chain. The proteins are macromolecules, made up of amino acids. Many amino acids combine to form a protein. The structure of the protein depends on the sequence of the amino acids present in the structure of protein. A different protein has a different sequence of amino acids.
"Water quality" may include the amounts of dissolved oxygen
and the levels of algal growth, pollutants which may be present and the pH level. Water quality effects also which types of organisms can
survive in a body of water.
Shellfish require a high level
of dissolved oxygen and their abundance is an indication of good water quality. Shellfish are sensitive to changes in the ecosystem and they cannot easily escape changes in the water quality. These are one of the reasons why shellfish are good indicators of water quality.