Ctenophores are characterized by presence of

Options

A. Comb plate
B. Colloblast
C. Bioluminescence
D. all of these

Answer

To answer the question about what Ctenophores are characterized by, let’s break down the information provided in the video transcript step by step.

### Step 1: Identify the Characteristics of Ctenophores
Ctenophores, also known as comb jellies or sea walnuts, are unique marine animals. They possess several distinct characteristics that set them apart from other organisms.

### Step 2: Understand the Key Features
1. **Radial Symmetry**: Ctenophores exhibit radial symmetry, meaning they can be divided into equal halves from any angle.
2. **Diploblastic Structure**: They are diploblastic, which means they have two primary germ layers (ectoderm and endoderm) with a gelatinous substance called mesoglea in between.
3. **Comb Plates**: They have eight rows of ciliary structures known as comb plates, which are used for locomotion.
4. **Bioluminescence**: Ctenophores are capable of bioluminescence, allowing them to emit light.
5. **Coloblasts**: They possess specialized cells called coloblasts that are used for capturing prey.

### Step 3: Analyze the Options
Given the options:
- Complete
- Coloblast
- Bioluminescence
- All of these

We can see that Ctenophores are characterized by the presence of coloblasts, the ability to exhibit bioluminescence, and the presence of comb plates.

### Step 4: Conclusion
Since all the mentioned characteristics (coloblasts, bioluminescence, and comb plates) are indeed present in Ctenophores, the correct answer is **D: All of these**.

### Final Answer
Ctenophores are characterized by the presence of coloblasts, bioluminescence, and comb plates. Therefore, the correct option is D: All of these.

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