Why are there increasing levels of biological containment procedures? what level of biological containment will be necessary to complete the experiments in this manual?

There is an increasing levels of biological contaminant procedures because they are necessary in preventing spores from becoming as dormant and that they are also responsible for preventing bacterial infections and as well as resistance of viruses. The level of biological contaminant necessary to complete experiments is to have a biological level of bio safety level 1 when there is a need of minimal potential hazard to the ones conducting the experiment.

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).