Diversity in Living Organisms

The antherozoid of Lycopodium is pear shaped with two flagella at the anterior end. The biflagellate antherozoids of Lycopodium resemble more to the antherozoids of Bryophytes, rather than those of vascular plants.

Gametophytes have sessile jacketed multicellular sex organs. The male is antheridium and female is archegonium. Antheridia form biflagellated (Selaginella, Lycopodium) or multiflagellated (Dryopteris) male gametes. Antheridium producing about 32 anthropoids. Each anthropoid is large antinuclear coiled and multi flagellate.

• Mosses are small flowerless plants that typically grow in dense green clumps or mats, often in damp or shady locations.
  
• Lichens are multicellular, eukaryotic but they have symbiosis as their mode of nutrition where algal component provides nutrition and fungal component helps in mineral absorption and protection.
• Lichens contain unicellular cyanobacteria if the algal component contains cyanobacteria but all cells are not unicellular as fungal myceliae are multicellular.
• So the correct answer is 'A composite organism made up of a fungus, that grows symbiotically with an algae or a cyanobacterium.'

Contractile vacuoles are membrane-bound organelles that pump excess water out of the protozoan. When the freshwater protozoan is placed in a marine environment it loses water due to exosmosis as salt concentration is high outside. The contractile vacuole disappears to prevent the loss of water from the organism because in the presence of contractile vacuoles the cell will be dehydrated. 

Glisson's capsule is the characteristic feature of 'mammals'.

Pteris (a fern) and Cycas (a gymnosperm) both produce multiciliated antherozoids.

Funaria (a moss) produces a protonema stage in its life cycle, whereas Marchantia (a liverwort) does not.

In moss, when the mature capsule begins to dry up, the thin walled cells of the annulus break and the operculum is thrown away. Dropping off the operculum is assisted by the outward hygroscopic movement of the underlying peristomial teeth. Due to this movement, slits between the inner thin walled peristomial teeth become wider and spores escape gradually through these slits. In a wet atmosphere, the wet peristomial teeth bend inwards and thus closing the slits and prevent the escape of spores. The seta of the mature sporophyte also exhibits hygroscopic movements. In dry weather, by loosing water, it twists and bents, thus helping in dispersal of spores. The sporogonium of Funaria is photosynthetic, hence semi-parasitic on gametophore. It differentiates into foot, seta and capsule. The foot embedded in the female receptacle and absorbs inorganic nutrients.

In Funaria, the androcyte mother cells divide diagonally and each forms two androcytes. The latter differentiate into biflagellate antherozoids. 

Rhizoids are branched, slender and multicellular. They are stout, brown, almost cable like and form the main anchoring strands. The rhizoids are colourless in the young stage, but become red or brown at maturity. The rhizoidal branches have oblique cross walls and grow down into soil. They help in anchorage and absorption.

The archegonium of Funaria typically possesses a long neck containing a series of neck canal cells, usually numbering between 6 and 10.

Funaria is anchored by multicellular, branched rhizoids that feature oblique septa.

Funaria spores contain chloroplasts, which allow them to begin photosynthesis immediately upon germination.

In Funaria, spore has small irregular mitochondria, numerous chloroplasts with poorly developed lamellae, small sparsely present dictyosomes and ER in the form of highly convoluted tubules near the plasma membrane.

Funaria possesses a juvenile filamentous autotrophic stage during life cycle, called as protonema. Moss plant (Funaria) develops on protonema as buds, while Marchantia is a liverwort in which distinct protonemal stage is absent.