Primary meristems are those which originate

Options

A. Since birth from embryonal tissue
B. During secondary meristem
C. By dedifferentiation
D. None of the above

Answer

### Step-by-Step Solution:

1. **Understanding Primary Meristems**:
- Primary meristems are a type of meristematic tissue in plants that are responsible for primary growth. This growth primarily involves an increase in length and height of the plant.

2. **Origin of Primary Meristems**:
- Primary meristems originate from embryonal tissue. This means they are formed during the early stages of plant development, specifically from the cells that make up the embryo.

3. **Characteristics of Primary Meristems**:
- These tissues consist of undifferentiated embryonic cells that are actively dividing. They have thin cell walls and large nuclei, which are typical features of meristematic cells.

4. **Evaluating the Options**:
- The question provides four options regarding the origin of primary meristems:
- (a) Since birth from embryonal tissue
- (b) During secondary meristem
- (c) By de-differentiation
- (d) None of the above
- Based on the understanding that primary meristems originate from embryonal tissue, we can conclude that option (a) is correct.

5. **Conclusion**:
- Therefore, the correct answer to the question is that primary meristems originate since birth from embryonal tissue.