Arrange the following steps of somatic hybridisation in a correct sequence.
A. Digestion of cell walls. B. Isolation of naked protoplasts. C. Fusion of protoplasts to get hybrid protoplast. D. Isolation of single cells from two different varieites of plants. E. Growing of hybrid protoplast to form a new plant.
Choose the correct answer from the options given below:
- A.
D, A, B, C, E
- B.
E, B, A, D, C
- C.
D, B, A, E, C
- D.
E, A, B, C, D
- Understand what somatic hybridisation means.
Given that somatic hybridisation is a technique used to fuse two somatic (body) cells from different plant varieties, bypassing normal sexual reproduction, in order to combine desirable traits from both parents.
- Identify the very first step.
Since the process starts with plant material from two different varieties, the scientist must first take single cells from each variety. Hence, this corresponds to step D — Isolation of single cells from two different varieties of plants.
- Determine what must happen before the cells can fuse.
Given that a plant cell is surrounded by a rigid cell wall, which physically prevents two cells from merging, this wall must be broken down using enzymes. Therefore, the next step is step A — Digestion of cell walls.
- Identify what remains once the wall is removed.
Since removing the cell wall leaves behind a cell bounded only by its plasma membrane, this is called a naked protoplast. Hence, the next step is step B — Isolation of naked protoplasts.
- Combine the protoplasts from the two varieties.
Given that naked protoplasts (without walls) can now merge freely, the protoplasts from the two different varieties are fused together to form a hybrid protoplast. So, the next step is step C — Fusion of protoplasts.
- Regenerate a full plant.
Since a hybrid protoplast is just a single fused cell, it must be grown under suitable conditions to develop into a complete new plant, called a somatic hybrid. Hence, the final step is step E — Growing of hybrid protoplast to form a new plant.
- Put the sequence together.
Given the reasoning above,
Hence, the answer is option A.