Define spermiogenesis and spermiation.

Explanation

### Step-by-Step Text Solution:

1. **Definition of Spermiogenesis**:
- Spermiogenesis is the process through which spermatids, which are the immature forms of sperm, undergo differentiation to become mature sperm cells.
- During this process, the non-motile spermatids transform into motile spermatozoa, which are capable of movement.

2. **Characteristics of Spermatids and Sperm**:
- Spermatids are non-motile and do not have the ability to swim.
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