The students of a college were working on regeneration using Planaria (Platyhelminthes) and Asterias (Echinodermata). Planaria was cut in three pieces, namely, a piece with head, with tail and the middle piece. Asterias (bearing five arms) was cut in such a way that after separation six pieces were obtained, namely, and arm with a portion of the central disc, four pieces cut from tips of each of the remaining arms and the remaining body. The animals were allowed to regenerate completely. How many planaria and Asterias respectively will be obtained after the completion of regeneration in both ?

Options

A. 1 , 1
B. 3 , 2
C. 3 , 6
D. 1 , 2

Explanation

To solve the problem of regeneration in Planaria and Asterias, we will analyze each organism separately and determine how many new individuals will be formed after regeneration.

### Step-by-Step Solution:

1. **Understanding Planaria Regeneration:**
- Planaria is a type of flatworm that can regenerate from its body parts.
- In the experiment, Planaria was cut into three pieces: one with the head, one with the tail, and one middle piece.
- Each piece of Planaria has the ability to regenerate into a complete organism.
- Therefore, from the three pieces, we can expect to get three new Planaria.

2. **Understanding Asterias Regeneration:**
- Asterias, commonly known as starfish, can also regenerate from their body parts.
- In this case, Asterias was cut into six pieces: one arm with a portion of the central disc, four tips from the remaining arms, and the remaining body.
- The piece that includes the arm with a portion of the central disc is capable of regenerating into a new starfish.
- The four tips of the remaining arms will not regenerate into new starfish because they lack the central disc.
- Therefore, only the piece with the central disc can form a new Asterias.
- This means that from the six pieces, we will get two new Asterias: one from the piece with the central disc and one from the remaining body.

3. **Final Count:**
- After regeneration, we will have:
- **3 Planaria** (one from each piece)
- **2 Asterias** (one from the piece with the central disc and one from the remaining body)

### Conclusion:
The final answer is:
- **Planaria: 3**
- **Asterias: 2**