I think the answer is ozone i hope i am right and hope this helps
Answer:

point mutation, change within a gene in which one base pair in the DNA sequence is altered. Point mutations are frequently the result of mistakes made during DNA replication, although modification of DNA, such as through exposure to X-rays or to ultraviolet radiation, also can induce point mutations
The answer for the above question is the Avascular Necrosis. It occurs as an interruption in the blood flow within the bone resulting in the death of the hematopoietic cells, osteocytes, and marrow fat cells making up the bony structure. It is also called osteonecrosis or ischemic bone necrosis, which occurs when there is loss of blood to the bone, since the bone is a living tissue that needs blood, this interruption of blood supply will result to the death of the bone.
Gause's Competitive Exclusion Principle
The 'competitive exclusion principle' (CEP) states that two species with identical niches cannot coexist indefinitely. ... Gause helped propel ecology by his approach of experimentally testing mathematical models, and his unifying the concept of the niche with resource competition.
Lysosomes break down nutrients and old cell parts