- A tail is a part of a sperm cell
- A tail is not part of an egg cell
- So, a tail is part of a sperm cell and not part of an egg cell

- A tail is part of a sperm cell and not part of an egg cell
- A characteristic is a part of the whole
- Therefore, a tail is a characteristic of a sperm cell but not of an egg cell

Hence, a tail is a characteristic of a sperm cell but not of an egg cell
Which is a characteristic of a sperm cell but not of an egg cell?
- A tail is a part of a sperm cell 
- A tail is not part of an egg cell 
- A characteristic is a part of the whole