It would be the first option. Adenine and thymine.
Taxonomy is the science of naming and classifying organisms based on structural comparisons and genetic evidence.
In multi-celullar organisms , the cell cycle produces groups of cells that perform the same function. These groups of cells form what it is called a tissue. A tissue is made up of cells that all are specialised to perform the same function. A bunch of tissues form an organ. Organs are more complex in structure and functions.
lots of different organs together form an organ system.
Due to white moths being in a dark environment (from environment changes), the moth has evolved its wings to become darker. Thus blending in with its environment to be less visible to birds. A way of survival. Their adaption is the darker wings to its dark environment
Respiratory system= breathing system
To keep our Respiratory system healthy we should:
1- never breathe in front of polluted areas
2- never pollute our areas
3- try to make our environment normal