The chloroplasts of algae usually lack

Options

A. Quantasomes
B. Lamellae
C. Pigments reticulum
D. Grana

Answer

### Step-by-Step Solution:

1. **Understanding Chloroplasts**: Chloroplasts are organelles found in plant cells and some algae that are responsible for photosynthesis. They contain chlorophyll, which gives them their green color.

2. **Structure of Chloroplasts**: Chloroplasts are double-membranous organelles with a unique internal structure. They contain thylakoids, which are disc-shaped structures where the light-dependent reactions of photosynthesis occur.

3. **Thylakoids and Grana**: Thylakoids can be stacked in groups called grana (singular: granum). These stacks are important for the efficiency of photosynthesis.

4. **Algal Chloroplasts**: In certain types of algae, specifically red algae and cyanobacteria (blue-green algae), the structure of chloroplasts differs from that of higher plants. In these algae, the thylakoids are not stacked; they are unstacked and exist as single thylakoids.

5. **Conclusion**: Due to the unstacked nature of thylakoids in red algae and cyanobacteria, these algal chloroplasts usually lack grana. Therefore, the correct answer to the question is that the chloroplasts of algae usually lack **grana**.