Q a. Ahmed worked on his crops of wheat and maize to produce a better-quality crop (which gives a more yield). In detail, write down how he altered his crop into a better yielding crop.

b. What is the name of the process that Ahmed used to breed his new better-quality wheat and maize.

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.