In Gymnosperms, the activity of sieve cells are controlled by _____.

(a)

Nearby sieve tube members

(b)

Phloem parenchyma cells

(c)

Nucleus of companion cells

(d)

Nucleus of albuminous cells

When a leaf trace extends from a vascular bundle in a dicot stem, what would be the arrangement of vascular tissues in the veins of the leaf?

(a)

Xylem would be on top and the phloem on the bottom

(b)

Phloem would be on top and the xylem on the bottom

(c)

Xylem would encircle the phloem

(d)

Phloem would encircle the xylem

Grafting is successful in dicots but not in monocots because the dicots have _______.

(a)

Vascular bundles arranged in a ring

(b)

Cambium for secondary growth

(c)

Vessels with elements arranged end to end

(d)

Cork cambium

Why the cells of sclerenchyma and tracheids become dead?

What are Sieve tubes ? Explain.

Distinguish the anatomy of dicot stem from monocot stem.