Question 2 5 pt
Carbon dioxide is released into the atmosphere by all of the following EXCEPT the
burning of fossil fuels.
depletion of the ozone layer.
burning of trees and forests,
burning of gasoline

your answer should be c) enjoy!

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.

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).