CSS Paper Botany 2010 MCQs

In the anatomy of a moss capsule, the columella is a central sterile column of tissue. Surrounding this columella is the spore sac, which contains the developing spores. This arrangement is characteristic of many mosses, where the spore sac forms a barrel-shaped or cylindrical layer around the central axis of the capsule.

The archegonia in Polytrichum are surrounded by specialized leaves known as perichaetial leaves. These archegonia are arranged in groups or clusters, typically containing 3 to 6 archegonia per cluster, accompanied by sterile hairs called paraphyses.

In many bryophytes, the sporocytes within the sporangium undergo meiosis to produce a tetrad of four haploid spores. This process is a fundamental aspect of the bryophyte life cycle, ensuring genetic diversity through the reduction division of the diploid sporophyte tissue into haploid reproductive units.

Funaria is a member of the division Bryophyta. Within this division, it is further classified under the class Bryopsida, the order Funariales, and the family Funariaceae. The question asks for the division level classification.

The capsule of Funaria is a complex structure differentiated into three distinct morphological regions: the apophysis (the sterile basal part), the theca (the central fertile part containing the spore sac), and the operculum (the lid-like apical part that covers the peristome). Each of these regions plays a specific role in the development, protection, and eventual release of the spores.

The protonema is the juvenile, filamentous stage that develops from the germinating spore. In most mosses, it is a transient, short-lived phase that eventually gives rise to the leafy gametophore, which represents the mature, dominant phase of the life cycle.

In the moss Funaria, the sporophyte is differentiated into three distinct parts: the foot, the seta, and the capsule. The foot is the basal, bulbous portion that remains embedded in the gametophyte tissue. It functions primarily as an anchoring organ and facilitates the absorption of water and nutrients from the parent gametophyte to support the developing sporophyte.

In bryophytes, the male sex organ is called the antheridium, which produces biflagellate male gametes known as antherozoids. The female sex organ is called the archegonium, which produces a single egg cell. These structures are multicellular and protected by a sterile jacket layer, which is a key adaptation for land plants.

In many mosses, the leaves surrounding the sex organs (archegonia or antheridia) are modified and collectively referred to as perichaetial leaves. The entire protective structure formed by these specialized leaves is known as the perichaetium. This structure provides mechanical protection and helps maintain a microenvironment suitable for fertilization.

The apophysis is the sterile, basal portion of the moss capsule, located just above the seta. It serves as a transition zone between the stalk and the spore-producing region of the sporangium, often containing stomata for gas exchange.