Why would a pigeon breeder select the offspring of pigeons with spotted bodies and then breed those offspring? to improve body coloring in future generations to see what new traits might appear next to determine if spotted bodies affect wing size to produce offspring with spotted bodies?

Me with these questions image attached

Astudent wants to test the hypothesis that fertilizer improves the growth rate of grass seeds. to test this hypothesis, the student put the same amount of grass seed in 3 containers with the same type of soil. the student measured the growth at the end of the week. all plants received equal amounts of water and sunlight. if you were asked to graph this data, what would you place on the x-axis? a. fertilizer b. water c. plant growth d. week one

Why has two different alleles for the same trait?