DNA is composed of nucleotides, which are composed of three parts:
1. A five carbon carbohydrate (pentose)
Pentose is classified as a monosaccharide (simple carbohydrate), and its molecular formula is represented by 
. They are water soluble molecules with sweet taste. Monosaccharides may have from three carbon atoms (trioses) to six (hexoses). In DNA is present pentose (5 carbon atoms)
2. A nitrogenous base
Nitrogenous bases are ring-shaped compounds that contain nitrogen in their molecular structure. They are classified into two groups: purines and pyrimidines
The purine bases are adenine (A) and guanine (G). They are larger and contain more than one ring in their structure,.
The pyrimidines, cytosine (C), uracil (U) and thymine (T), are smaller and composed of a single ring.
3. One or more phosphate groups
A phosphate consists of a trivalent anion that contains one phosphorus atom and four oxygen atoms. Its molecular formula is expressed by 
.
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.
It gets heavier and heavier because it is pressure that holds the earth together and keeps the core of earth a hot SOLID ball instead of liquid
I believe your answer is A.
Cellular Respiration creates energy for the cells.
Hope this helps and please mark as brainliest!
