Question
Biology Question on Anatomy of Flowering Plants
In a dorsiventral leaf, location of palisade tissue and phloem is respectively on the______ surfaces.
A
adaxial and abaxial
B
adaxial and adaxial
C
abaxial and adaxial
D
abaxial and abaxial
Answer
adaxial and abaxial
Explanation
Solution
Dorsiventral (bifacial) leaves are commonly horizontal in orientation with distinct upper (adaxial) and lower (abaxial) surfaces. Mesophyll is distinguishable into palisade and spongy tissues with palisade usually restricted to the upper (adaxial) side. Vascular bundles are conjoint and collateral i.e., they possess both xylem and phloem which lie on the same radius. Xylem lies towards the upper (adaxial) side of leaf while phloem lies towards the lower (abaxial) side of leaf. Most of the dicotyledonous leaves are dorsiventral.