During fertilization, a sperm enters an egg and the two join to form a zygote. Which statement is true regarding the combination of allele characteristics in the zygote? ANYONE KNOW??!!!

Which is one way that sinkholes can form? a) tornadoes touch down and destroy trees and brush b) rivera overflow during a storm and wash away nearby land c) rainwater flows away from a depression in the ground d) groundwater dissolves the limestone and other rocks in the ground