1. | cork and cork cambium |
2. | cork cambium and cork |
3. | secondary cortex and cork |
4. | cork and secondary cortex |
1. | Gymnosperms lack vessels in their xylem. |
2. | Gymnosperms have albuminous cells and sieve cells. |
3. | Gymnosperms lack sieve tubes and companion cells. |
4. | Gymnosperms lack secondary growth. |