Question

A small portion of cane-sugar stem between the two successive nodes is cut off and sown in the soil normally. New plants will be:
A) formed normally 
B) Not formed
C) Without juice                 
D) without nodes

Answer 1

Hint: We need to keep in mind the role of nodes in the reproduction of sugarcane. In this case, nodes are not sown. The impact of this step will determine whether or not propagation occurs.

Complete Step-by-Step Answer: Sugarcanes are tropical perennial grass, primarily cultivated for their sweet juice which is crucial in the production of sugar. Sugarcane can be propagated by both sexual and vegetative methods. It can be grown from either seed or through stem cutting. Though both methods are equally effective, vegetative propagation is preferred keeping in mind its economic importance and ease of execution.
The stem of sugarcane contains nodes and internodes. Nodes are the region of activity of meristematic tissues and internodes are the region present between the two nodes. A growth ring, coated with a waxy layer, is present just above each node and it is an active site of cell elongation.
According to the question, the portion of sugarcane between two successive nodes is cut off. This means the internodal region is taken and sown. But internodes lack meristematic cells and they can not give rise to new plants. Nodes contain meristematic tissue capable of totipotency and hence are better suited for the vegetative propagation of sugarcane. Here, nodes are missing. Hence, the sown part of sugarcane will be unable to produce root primordials and will not propagate even while in contact with damp soil.

So the correct answer is option B.

Note: Vegetative propagation methods are the simplest as they involve a single parent. In addition to the ease, there is an added advantage that the genetic material of only one parent is inherited by the offspring plant. So vegetative propagation can also aid in the maintenance of consistent quality and flavor in plant products.