Tag: botany

A. Medulla – central part of the stele.

B. Stele – central part of the root and dicot stem, includes pericycle, vascular bundles, medulla, medullary rays or conjuctive tissue.

C. Cortex – middle part of the dicot stem and root, includes hypodermis, general cortex and endodermis.

D. Exodermis – outer part of mature monocot root.

So, the correct option is ‘Cortex’.

A.Endodermis - Inner most layer of cortex

B.Epidermis – outer layer of organs.

C.Exodermis – outer most layer of mature monocot root.

D.Hypodermis – it is present inner to the epidermis in stems.

So, the correct option is ‘Endodermis’.

Stele in which vascular bundles are arranged in scattered manner in the ground tissue, is called Atactostele. It is found in monocot stem.

In the anatomy or internal structure of dicot stem, epidermis, followed by cortex, followed by endodermis, pericycle, phloem, xylem, medulla are present from outer to inner.

Cork cambium arises from outer most layer of the cortex which is the ground tissue. 

Grafting is a technique whereby tissues from one plant are placed or inserted into another in such a way that the vascular tissues of both the plants may join together. The plant which is selected for its roots is called as the stock and the one selected for its stems and leaves and flowers is called as the scion. For successful grafts, the events that should take place is the production of the callus tissue between the cells of the stock and scion. 

In certain plants like Strychnos, anomalous secondary growth occurs where the cambium produces phloem islands within the xylem, a phenomenon known as interxylary phloem.

Urtica is a well-known example of a plant that exhibits anomalous secondary growth, specifically the presence of phloem or parenchyma islands within the wood.

Ochroma, commonly known as Balsa wood, is famous for having an extremely low density and specific gravity, often well below 0.2.

Fibre is a narrow, elongated cell with thick lignified wall and narrow lumen tapering to a wedge-shape at both ends. Sometimes the deposition of lignin is so thick as to obliterate the central lumen. The fibres appear more or less angular in cross-sectional view with little intercellular spaces. The cell wall is pitted and may show slight indentation (ex. Zingiber).