Which of the following statements about the structure of a human sper…

The correct answer is Option (3) → The neck of the sperm lies between the middle piece and the tail.

A sperm is made of a head, a neck, a middle piece and a tail, in that order from front to back. In Figure 2.6 the neck is the short part that joins the head to the middle piece.

Option (1) A plasma membrane envelops the whole body of the sperm. — A correct statement. A plasma membrane covers the whole body of the sperm, from the head to the tail.

Option (2) The middle piece possesses numerous mitochondria, which produce energy for the movement of the tail. — A correct statement. The mitochondria in the middle piece produce the energy for the movement of the tail.

Option (3) The neck of the sperm lies between the middle piece and the tail. — An incorrect statement. The neck lies between the head and the middle piece. The part between the middle piece and the tail is not the neck; the middle piece leads straight into the tail.

Option (4) The movement of the tail facilitates sperm motility, which is essential for fertilisation. — A correct statement. The moving tail makes the sperm swim, and this motility is essential for fertilisation.

Note: The order of the parts is printed in one short line of text, and Figure 2.6 shows it at a glance. A labelled diagram can carry a whole question, so spend a minute on every one of them.

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.”