During embryogenesis archenteron is preceded by
(a) Blastulation
(b) Neuralation
(c) Gastrulation
(d) Implantation

Options

A. Blastulation
B. Neuralation
C. Gastrulation
D. Implanatation

Answer

To solve the question regarding which process precedes the formation of the archenteron during embryogenesis, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks which process occurs before the formation of the archenteron during embryogenesis.

2. **Define Archenteron**: The archenteron is a primitive gut structure that forms during the gastrulation phase of embryonic development. It is crucial for the development of the digestive system.

3. **Examine the Options**:
- **(a) Blastulation**: This is the process that leads to the formation of the blastula. It occurs before gastrulation but does not directly lead to the formation of the archenteron.
- **(b) Neuralation**: This is the process of forming the neural tube from the ectoderm. It occurs after the blastula stage but before the archenteron is formed.
- **(c) Gastrulation**: This is the stage where the archenteron is formed. Therefore, it cannot precede its own formation.
- **(d) Implantation**: This is the process where the embryo attaches to the uterine wall, which occurs before the formation of the archenteron but is not directly related to its formation.

4. **Identify the Correct Answer**: Since the archenteron is formed during gastrulation, the process that directly precedes it is neuralation. Therefore, the correct answer is **(b) Neuralation**.

### Final Answer:
(b) Neuralation