The annual rings are bands of

Options

A. spring wood and autumn wood
B. secondary xylem and primary xylem
C. xylem and phloem
D. secondary phloem and primary phloem

Answer

**Step-by-Step Solution:**

1. **Understanding Annual Rings**: Annual rings are visible bands found in the cross-section of a tree trunk. They represent the growth of the tree over a year.

2. **Formation of Annual Rings**: These rings are formed due to the activity of the vascular cambium, a layer of tissue that contributes to the growth in diameter of the tree.

3. **Influencing Factors**: The formation of these rings is influenced by physiological and environmental factors, such as seasonal changes in temperature and rainfall.

4. **Composition of Annual Rings**: Each annual ring consists of two types of wood:
- **Spring Wood (Early Wood)**: This part is formed during the spring when the cambium is most active. It is lighter in color and has a lower density.
- **Autumn Wood (Late Wood)**: This part is formed during the autumn when the cambium is less active. It is darker in color and has a higher density.

5. **Conclusion**: The annual rings are composed of both spring wood and autumn wood, which together represent one year of growth.

**Final Answer**: The annual rings are bands of spring wood and autumn wood.

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