The exchange of gases between the alveoli and capillaries of the lungs happens because of what?
the movement of substances from an area of high
concentration to an area of low concentration

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

the last one: artificial selection/genetic engineering

plant breeding is modifying the genetic composition of the plant - but this isn't cloning (which is specifically introducing a gene into a genome). but you are artificially selecting for the phenotype that you want.

the second one is literally genetic engineering - the gene would have been cloned first and then inserted or genetically engineered into the new plant cell (the cotton).