Which one of the following BEST describes genotype-by-environment interactions?

Under certain circumstances, two organisms with identical genotypes have different phenotypes.
	Genetic and environmental factors combine to influencephenotype.
	Under certain circumstances, two organisms with identicalphenotypes have different genotypes.
	The environment of an organism determines the genetic make-upof that organism.
	The genotype of an organism determines how that organism willbehave in its environment.

Which of the following would be good examples ofgenotype-by-environment interactions? (Select all that apply.)

	two different mutants of mice that share similar fat metabolismabilities
	a line of dairy cows that increases milk yield in relation tofeed amount
	a strain of mutant mice that becomes obese regardless of feedamount
	two different strains of corn that differ in height due togenotype
	a line of chickens whose eggshells are extra thick regardlessof feed type
	a strain of corn whose yield varies with the amount ofnutrients in the soil