Why do only male gametes have a tail?

From a cellular biology perspective, the tail has a complex structure with ATP-powered dynein motors that make it whip and move. This specialization is unique to male gametes.

In evolutionary terms, motility in male gametes increases the chances of reaching the egg and successful fertilization. Female gametes focus on nutrient storage and support for the zygote instead.

Male gametes, like sperm cells, have tails called flagella which help them swim towards the female gamete for fertilization. Female gametes, such as eggs, are stationary and do not need to move.

The tail is a specialized structure containing microtubules, allowing sperm to propel itself in fluid. Eggs rely on passive transport and supportive structures like the fallopian tubes.

Think of it like this: sperm are the "travelers," and eggs are the "destination." Only the travelers need engines (tails) to reach the destination.