The question asks to identify a moss commonly used as packing material for the trans-shipment of living organisms. This requires knowledge of the specific properties and commercial applications of different types of mosses.
A) Sphagnum — Sphagnum moss has an excellent water-holding capacity (it can hold water many times its own weight) and also possesses antiseptic properties due to its acidic nature. These qualities make it an ideal packing material for the trans-shipment of living plant materials, keeping them moist and preventing fungal or bacterial growth during transit.
The question asks about the differentiation of the sporophyte in bryophytes. To answer this, we need to recall the life cycle and structural characteristics of bryophytes, specifically the sporophytic generation.
B) Foot, seta and capsule — This correctly describes the three differentiated parts of the sporophyte in bryophytes.
The question asks about the first stage of the gametophyte in mosses. Mosses exhibit a life cycle with alternation of generations, where both sporophyte and gametophyte stages are prominent. The gametophyte generation begins with a specific developmental stage after spore germination.
B) Protonema stage — This is the correct answer. The protonema is the filamentous, thread-like structure that develops directly from the germinating spore and represents the first stage of the gametophyte in mosses.
This question tests knowledge about the reproductive structures of bryophytes. It requires identifying the specific term for the female sex organ in this plant group.
Correct Option: A) Archegonium is the correct term for the female sex organ in bryophytes.
The question asks about the evolutionary significance of Pteridophytes, specifically what key characteristic they were the first terrestrial plants to possess. We need to recall the evolutionary timeline of plant groups and their defining features.
C) Vascular tissues – xylem and phloem. Pteridophytes are often referred to as the first true terrestrial plants because they developed a specialized vascular system (xylem for water transport and phloem for food transport). This innovation allowed them to grow taller and survive in drier conditions than their bryophyte ancestors, which lack true vascular tissues.
The question asks to identify the dominant phase in the life cycle of pteridophytes. This requires knowledge of the typical life cycle of pteridophytes and the characteristics of their sporophyte and gametophyte generations.
Correct Option: D) Sporophyte
In pteridophytes, the sporophyte is the dominant, independent, photosynthetic, and well-differentiated plant body. It is the phase that constitutes the main plant we observe.