The nucleus is present in which part of the mammalian male sperm?

The correct answer is Option (1) → Head

A human sperm has four parts: a head, a neck, a middle piece and a tail, all covered by a plasma membrane. Each part has its own job.

Option (1) Head — Correct. The sperm head contains an elongated haploid nucleus. Its front part is covered by a cap called the acrosome, which holds enzymes that help the sperm enter the ovum.

Option (2) Tail — Incorrect. The tail moves the sperm forward (sperm motility). It carries no nucleus.

Option (3) Middle piece — Incorrect. The middle piece has numerous mitochondria, which make the energy needed for the movement of the tail. It does not hold the nucleus.

Option (4) Neck — Incorrect. The neck is the short part that joins the head to the middle piece. The nucleus lies in the head, in front of the neck.

NCERT Extract:
Gametogenesis – “… Let us examine the structure of a sperm. It is a microscopic structure composed of a head, neck, a middle piece and a tail (Figure 2.6). A plasma membrane envelops the whole body of sperm. The sperm head contains an elongated haploid nucleus, the anterior portion of which is covered by a cap-like structure, acrosome. The acrosome is filled with enzymes that help fertilisation of the ovum. The middle piece possesses numerous mitochondria, which produce energy for the movement of tail that facilitate sperm motility essential for fertilisation.”

Figure 2.6 Structure of a sperm