The action or process of fertilizing an egg, female animal, or plant, involving the fusion of male and female gametes to form a zygote. The gametes that participate in fertilisation of plants are the sperm (male), and the egg cell, and in flowering plants a second fertilisation event involves another sperm cell and the central cell which is a second female gamete. In flowering plants there are two sperm from each pollen grain.
Answer:
D
Explanation:
Relative Age Determination. Superposition of rock units is a very simple and straightforward method of relative age determination. The principle states that in a sequence of undeformed sedimentary rocks the oldest beds are at the bottom and the youngest ones are at the top.