For each of the following questions, four choices have been provided. Select the correct alternatives. Head of sperm contains (a) Nucleus only (b) Nucleus and mitochondria (c) Mitochondria and acrosome (d) Nucleus and acrosome

The spermatozoon, or sperm cell, is an intricately structured unit of reproduction with the vital role of delivering male genetic information to the female egg. It is made to travel efficiently and contain the necessary components for successful fertilization. Structurally, a spermatozoon consists primarily of a head, a midpiece, and a tail. Each section has a specific function imperative for the journey to and penetration of the egg. The head, covered by a cap-like structure called the acrosome, houses genetic material, while the midpiece is packed with mitochondria to provide energy. The tail, called the flagellum, propels the sperm by whipping back and forth.
The streamlined design of a spermatozoon is an excellent example of form following function, as every part is essential for its role in reproduction.

The nucleus within the head of a sperm cell contains the genetic material, which represents half of the DNA required to form a new organism. During the process of spermatogenesis, the sperm undergoes a specialized type of cell division called meiosis. This halves the number of chromosomes from 46 to 23, ensuring that when it combines with the female egg - also containing 23 chromosomes - the resulting embryo will have the proper chromosome number of 46. The highly condensed genetic material in sperm is meticulously packaged, allowing it to be delivered efficiently to the egg during fertilization.

The acrosome, derived from the Greek words 'akros' meaning tip and 'soma' meaning body, is a specialized structure that forms a cap over the anterior half of the sperm's head. The acrosome contains digestive enzymes that are crucial for fertilization. Upon reaching the ovum, the acrosome reacts in a process known as the acrosome reaction. This releases enzymes like hyaluronidase and acrosin which help digest the protective layers surrounding the egg - primarily the zona pellucida. This digestion is the key to allowing the sperm to penetrate and deliver its genetic material into the egg for successful conception.

Mitochondria are often referred to as the cell's powerhouse, and in sperm, they play a critical role in providing the energy required for its lengthy journey towards the egg. The mitochondria are densely packed in the midpiece of the sperm cell, spirally arranged around the tail's base to supply steady and efficient energy production. Energy in the form of adenosine triphosphate (ATP) is generated through a process known as cellular respiration. This energetic support is essential for the endurance and motility of the sperm as it moves through the female reproductive tract seeking the egg. Without a sufficient supply of energy from the mitochondria, the sperm would not be able to sustain the necessary motility to reach and fertilize the egg.