S.N. |
Primary cell wall |
Secondary cell wall |
1. |
It is formed in a growing cell. |
It is formed in a mature cell. |
2. |
It lies inner to the middle lamella. |
It lies inner to the primary cell wall outside the cell membrane. |
3. |
It is present in all the plant cells. |
It is present in certain cells only. E.g. cells involved in mechanical support and water transportation. |
4. |
It is elastic and capable of expansion in a growing cell. |
It is rigid and incapable of expansion. |
5. |
It grows in thickness by intussusception (growth by the deposition of cellulose). |
It grows in thickness by accretion (growth or increase by the gradual accumulation of additional layers or matter). |
6. |
It consists of a single layer of wall material. |
It consists of 3 or more layers of wall material. |
7. |
It is 1-3µm thick. |
It is 5-10µm thick. |
8. |
Its cellulose micro-fibrils are short, wavy and loosely arranged. |
Its cellulose micro-fibrils are long, straight and compactly arranged. |
9. |
It lacks pits. |
It has pits at certain places. |
10. |
It lacks additional materials. |
It has additional materials like lignin, suberin etc. |
11. |
Its water content is about 60%. |
Its water content is about 30-40%. |
12. |
It has relatively low cellulose content. |
It has relatively high cellulose content. |
13. |
It has relatively high hemicellulose, protein and lipid contents. |
It has relatively low hemicellulose, protein and lipid contents. |