Question

Which among the following statements is correct to indicate the difference between sperm and egg

• A. Cytoplasm in sperm is more abundant than in egg
• B. Accessory membranes are absent in sperm but present in egg
• C. Nucleus is clear in sperm and very compact in egg
• D. Mitochondria from a sheath in egg and diffused in sperm

Answer 1

Answer: (B)

Accessory membranes are absent in sperm but present in egg

A motile, haploid male gamete is called sperm, while nonmotile haploid female gamete is called ovum or egg cell. A sperm joins an ovum to form the zygote, that normally develops into an embryo.

The mammalian sperm cell consists of head, neck, a midpiece and a tail and is surrounded by a plasma membrane. The head contains the nucleus with densely coiled chromatin fibres, surrounded anteriorly by an acrosome, which contains enzymes used for penetrating the female egg. The neck contains the sperm centriole.The midpiece has a central filamentous core with many mitochondria spiralled around it.The tail has contractile proteins and It executes lashing movements.

The egg cell is a large cell with a lot of cytoplasms, multiple mitochondria and a nucleus dissolved in the cytoplasm.The egg cell is covered with a thick outer coating known as the zona pellucida, a layer of carbohydrate covered proteins that surrounds the plasma membrane. It is also called as an accessory membrane. It is the main differentiating feature between egg and sperm.

Thus, the correct answer is option B.