Answer:
In all organisms, the instructions for specifying the characteristics of the organism are carried in DNA, a large polymer formed from subunits of four kinds (A, G, C, and T). ...
Most of the cells in a human contain two copies of each of 22 different chromosomes. ...
Changes in DNA (mutations) occur spontaneously at low rates.
Answer: They do affect the health of an ecosystem.
Explanation: In an ecosystem there are many things that are biotic and abiotic. For an example: water is abiotic and plants/animals are all biotic, the water is not living but it keeps the ecosystem alive by quenching the thirst of the plants growing from the ground and the animals roaming around on the land. Dead animals and plants are not abiotic and they are now providing food for fungi and bacteria. Without the abiotic factors, it would be difficult for the biotic to survive.
The small intestine has cilia to absorb nutrients and reabsorb water
Perhaps the answer your looking for is, a tumor suppressor gene.