Anatomy Of Flowering Plants Question 9
Question: Abnormal secondary growth is observed in:
Options:
A) Dracaena
B) Wheat
C) Ginger
D) Rice
Show Answer
Answer:
Correct Answer: A
Solution:
First we should know about secondary growth to answer this question. Secondary growth is the growth arising from cell division inside the cambia or lateral meristem and causing thickening of the stems and roots. Secondary growth occurs in most seedlings but typically monocots lack secondary development. It varies from the usual pattern of other seedlings if they have secondary development.
Now, let us find the solution from the options-
->Vascular cambium is produced in certain members of plants such as Dracaena, Agave, Yucca, Lomandra, Aloe arborescens, Sansevieria, Kingia, etc. from the outer area of the soil tissues.
->Parenchyma produced by the vascular cambium to the outside and secondary vascular bundles developed to the inside.
->In certain plants the girth of the stern rises unchanged, like-Palm, Tulipa, Musa, etc. These plants are of a particular type of apical meristem. This is called primary meristem thickening.
->This apical meristem is accountable for the plant’s growth both in length and girth (width). In Dracaena, however, irregular secondary growth is observed, and not in rice, wheat, and ginger.
Thus, the correct option is option (A) i.e. Dracaena.
BETA
