Question

multiple choice question
what is fertilization?
fertilization takes place in the gonads and decreases chromosome numbers in the gametes.
fertilization describes the penetration of the sperm into the egg and the fusion of the egg and sperm nuclei.
fertilization is the stage in development when the zygote is a solid ball of cells.
fertilization occurs when the primary oocyte is released from the corpus luteum.

Explanation:

Fertilization is the process where a sperm penetrates an egg and their nuclei fuse. The first option describes meiosis (occurs in gonads, reduces chromosome number). The third option describes a morula (stage of embryonic development). The fourth option is incorrect as primary oocyte release is part of oogenesis and not fertilization.

Answer:

Fertilization describes the penetration of the sperm into the egg and the fusion of the egg and sperm nuclei.