Proctodaeum in rabbit is

Options

A. A part of large intestine lined by ectoderm
B. A part of large intestine lined by endoderm
C. A part of large intestine lined by mesoderm
D. Embryonic intestine

Explanation

To answer the question regarding the proctodaeum in rabbits, we will follow these steps:

### Step 1: Understand the term "Proctodaeum"
The proctodaeum refers to the posterior part of the digestive tract in animals, which is derived from the ectoderm layer during embryonic development. It is essentially the part of the gut that connects to the anus.

**Hint:** Remember that the proctodaeum is associated with the ectoderm layer and is located at the posterior end of the digestive system.

### Step 2: Identify the structure associated with the proctodaeum
In rabbits, the proctodaeum is primarily associated with the large intestine. The large intestine is the final part of the digestive system where water is absorbed and waste is prepared for excretion.

**Hint:** Focus on the relationship between the proctodaeum and the large intestine to understand its function.

### Step 3: Determine the germ layer that lines the proctodaeum
The proctodaeum is lined by the ectoderm. This is important because the ectoderm is one of the three primary germ layers in the embryo, and it contributes to the formation of the outer layer of the body, including the skin and the lining of the gut at the posterior end.

**Hint:** Recall the three germ layers (ectoderm, mesoderm, endoderm) and which one is responsible for the outer lining of certain structures.

### Step 4: Choose the correct option
Based on the information gathered, the correct answer to the question "Proctodaeum in rabbit is" would be that it is part of the large intestine lined by ectoderm.

**Hint:** When selecting an answer, ensure it aligns with the understanding that the proctodaeum is associated with the ectoderm layer.

### Final Answer
The proctodaeum in rabbits is part of the large intestine lined by ectoderm.