Assertion: All embryo with 8 to 16 blastomeres is called a morula.
Reason: The morula containues to divide and transforms into trophoblast.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Assertion:**
- The assertion states that an embryo with 8 to 16 blastomeres is called a morula.
- This is correct because during the cleavage stage of embryonic development, the zygote divides multiple times without increasing in size, resulting in a cluster of cells known as blastomeres. When there are 8 to 16 blastomeres, the structure is indeed referred to as a morula.

2. **Understanding the Reason:**
- The reason states that the morula continues to divide and transforms into a trophoblast.
- This statement is incorrect. While the morula does continue to divide, it does not transform into a trophoblast. Instead, the morula develops into a blastocyst, which consists of an outer layer called the trophoblast and an inner cell mass. The trophoblast is formed during the blastocyst stage, not from the morula itself.

3. **Conclusion:**
- The assertion is true, but the reason is false. Therefore, the correct answer is that the assertion is correct, but the reason is not true.