Question
Biology Question on Pteridophytes
In fern plant, the ejection of spores with force is achieved by the:
A
sporangiophore
B
annulus
C
stomium
D
indusium
Answer
annulus
Explanation
Solution
In annulus, due to presence of thickening along the radial and inner tangential walls, their upper walls contract and the inner ones straight, and annulus coils which exerts pressure on the wall resulting in breaking of the capsule between the cells of stomium thereby releasing the spores.