Final answer:
The correct answer is option 2. The acrosome, which is located at the front of the sperm head, contains the necessary enzymes to penetrate the oocyte. It releases enzymes during the acrosomal reaction to allow sperm to reach and fertilize the oocyte.
Step-by-step explanation:
The portion of the sperm that contains the enzymes needed to penetrate the oocyte is the acrosome. The acrosome is found at the very front of the sperm's head and is filled with enzymes that initiate the acrosomal reaction. This reaction involves the release of digestive enzymes that break down the layers surrounding the oocyte, namely the corona radiata and the zona pellucida. This process allows the sperm to eventually make contact with the oocyte and release its genetic material.
While the head of the sperm cell contains the nucleus with the male DNA, the midpiece of the sperm is packed with mitochondria which provide the energy required for movement. The tail, also known as the flagellum, contributes to the sperm motility, allowing it to swim towards the oocyte. This efficient structure and organization enable the sperm to reach, penetrate, and potentially fertilize the oocyte.