Biogenesis of chloroplast and mitochondria is

Options

A. de novo
B. from ER/nuclear membrane
C. from preexisting organelle
D. GERL system

Answer

### Step-by-Step Solution:

1. **Understanding Biogenesis**:
- Biogenesis refers to the process by which living organisms develop from pre-existing life. In the context of chloroplasts and mitochondria, it implies that these organelles arise from existing chloroplasts and mitochondria rather than being formed from non-living matter.

2. **Characteristics of Chloroplasts and Mitochondria**:
- Both chloroplasts and mitochondria are semi-autonomous organelles. This means they have their own DNA and can replicate independently within the cell. They are involved in essential processes: chloroplasts in photosynthesis and mitochondria in cellular respiration.

3. **Division of Organelles**:
- Chloroplasts and mitochondria replicate through a process similar to binary fission, which is the method by which prokaryotic cells divide. This allows them to increase in number as the parent cell divides.

4. **Formation of New Organelles**:
- When a parent cell divides, it distributes its organelles, including chloroplasts and mitochondria, to the daughter cells. Thus, new chloroplasts and mitochondria are formed from the existing ones during cell division.

5. **Evaluating Options**:
- The question may provide several options regarding the biogenesis of chloroplasts and mitochondria. Based on the understanding of their semi-autonomous nature and division, one can eliminate incorrect options.
- For example, if an option suggests that chloroplasts and mitochondria are formed from scratch (like "green mode"), that would be incorrect.

6. **Conclusion**:
- The correct understanding of the biogenesis of chloroplasts and mitochondria is that they arise from pre-existing organelles through a process of division and distribution during cell division.