Final answer:
A polar body is much smaller than a primary oocyte. It is a product of oogenesis, where a primary oocyte divides to form a secondary oocyte and a polar body, the latter usually degrading over time.
Step-by-step explanation:
A polar body is a small haploid cell that is formed as a byproduct during oogenesis, which is the process of egg cell development. When a primary oocyte undergoes meiosis, it results in one large cell, the secondary oocyte, and a much smaller cell called a polar body. Secondary oocytes have most of the cytoplasm and organelles from the original primary oocyte and are much larger than the polar bodies. Polar bodies generally do not participate in reproduction and degrade over time. The process of oogenesis occurs in the ovary's outermost layer, where a primary oocyte is arrested in the first meiotic division until after puberty. When meiosis resumes, it results in a secondary oocyte that completes meiosis only if fertilized by a sperm, leading to another polar body and a mature egg.