Describe the post-zygotic events leading to implantation and placenta formation in humans. Mention any two functions of placenta.

Explanation

### Step-by-Step Text Solution

1. **Formation of Zygote**: The process begins with the fusion of a male sperm and a female ovum, resulting in the formation of a diploid zygote.

2. **Cleavage Stage**: After zygote formation, the zygote undergoes mitotic divisions, a process known as cleavage. This leads to the formation of smaller cells called blastomeres.

3. **Morula Formation**: As cleavage continues, the zygote develops into a solid ball of cells known as the morula, which typically consists of 8 to 16 blastomeres.

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