Mantle
In mollusks with shells, the outer cells of the mantle secrete
calcium carbonate and conchiolin to form the shell. The mantle is the body wall
of a mollusk. It resides below the shell where it covers the body of the
animal.
The cleanliness of a ecosystem or how healthy it is. It determines how clean an environment/ecosystem is. You need all types of animals living there, therefore making it more healthy. The more healthy, the more we can say that it is biodiverse.
Biology is the study of living organisms, divided into many specialized fields that cover their morphology, physiology, anatomy, behavior, origin, and distribution.
This is basically the definition of biology, so you may need to add a little more detail. This is a great way to get it started though!!!
Hope this helps!!
I believe the structure organelle that may be faulty is Mitochondria. Mitochondria is a cellular organelle that is involved in cellular respiration a process that uses glucose to yield water and carbon dioxide coupled with production of energy in the form of ATP. Melas meaning mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes is a conditions that affects body systems especially the brain and the nervous system and muscles.
The answer would be B. nucleic acids.