Activity 12.7 Let us compare to compare the cross section of a fern stem. Class 9

Activity 12.7 Let us compare to compare the cross section of a fern stem. Class 9

Activity 12.7 Let us compare

Aim: To compare the cross section of a fern stem (pteridophyte) with that of a sunflower stem (higher plant).

Observation: In fern stem:

Vascular tissues (xylem and phloem) are less organised. They are often arranged in a simple, scattered or central pattern. Their structure is less complex, (as you can see in fig. (a).

In sunflower stem (higher plant):

Vascular tissues are well-developed and organised. They are arranged in a ring pattern. Presence of distinct xylem and phloem with better complexity (as in fig. (b).

Conclusion: The vascular tissues in ferns are simpler and less organised, whereas in higher plants like sunflower, they are well-developed and arranged in systematic way. This shows that higher plants are more advanced in structure and function as compared to pteridophytes.