Question

Offset is one internode long runner, and every node bears a phylloclade rosette of leaves and a tuft of roots. It is found in aquatic plants like
A.Hydrilla
B. Pistia
C. Eichhornia
D. Both B and C

Answer 1

Hint: A part of a branch or stem through which a plant can replicate asexually and produce a new daughter plant is called an offset. Plants use offset as a type of vegetative reproduction. These are clones of plants and are genetically the same as them. These are developed by the plant’s main stem’s mitotic division.

Complete Step-by-step answer:

Offsets are a vegetative portion of a plant. They are produced by mitosis as this division takes place in somatic cells. Offsets are daughter plants that are genetically like the parent and are generated by sexual reproduction.
Offsets are one internode long, dense, small runners which bear a cluster of leaves in a rosette type at the water or ground level and adventitious roots under water or ground level that arise from all nodes, e.g., Eichhornia crassipes, Pistia (water lettuce), etc.  
The function of offset is to disseminate plant species by propagating toward a new niche. Offsets form once the meristem area of plants, like homologous structures or axillary buds, differentiate into a new plant with the capacity to become self-sustaining. This is common in species that develop underground storage organs, like corms, bulbs, and tubers. Lilies and tulips are examples.

Therefore the correct answer is Option D.

Note: Aquatic plants are plants that have adapted to living water environments (freshwater or saltwater). They are also called macrophytes or hydrophytes to differentiate them from algae and other microphytes. A macrophyte is a plant that grows in or close to the water and is either submerged, emergent or floating.