At what stage of development, does the human embryo gets implanted to inner lining of uterus

Explanation

**Step-by-Step Solution:**

1. **Understanding Fertilization**: The process begins with the fertilization of the ovum (egg) by sperm, which typically occurs in the fallopian tube. This is referred to as "day 0" of development.

2. **Early Cell Division**: After fertilization, the zygote undergoes a series of cell divisions. Initially, it divides to form a two-cell stage, then a four-cell stage, and continues to divide until it reaches the eight-cell stage.

3. **Formation of the Morula**: As cell division continues, the embryo develops into a solid ball of cells known as the morula. This stage occurs approximately 3-4 days after fertilization.

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