Share Answer Bryophytes and pteridophytes both have alternation of generation. The gametophytic phase is dominant in bryophytes whereas in pteridophytes it is short lived. Sex organs are embedded is some members of bryophytes and pteridophytes. Sperms are flagellate and so water is required for fertilization. Sterile jacket is present around the sex organs for protection. Archegonium appeared for the first time in bryophytes in plant kingdom. <br /> It is a flask shaped structure. It has swollen basal portion called venter and upper elongated neck. The venter has egg cell and venter canal cell. There are 4-6 vertical rows of neck cells enclosing neck canal cells in bryophytes. The archegonia have short neck made of four rows of vertically elongated cells that encloses four neck canal cells in pteridophytes.

Share Answer Nostoc belongs to cyanophyceae. In this entire class sexual reproduction is completely absent. It reproduces by colony formation, hormogonia, akinetes, heterocysts and endospres. However genetic recombination has been observed. It may be probably through transformation or conjugation. <br /> The other three algae- Spirogyra, Ulothrix and Volvox belong to chlorophyceae. The members of this class show isogamous, anisogamous and oogamous type of sexual reproduction.

Share Answer Funaria is known as common moss or green moss. The plant body is foliose that consists of stem axis which bears many leaves and instead of roots, rhizoids are present. It is gametophytic (n) and independent. <br /> It bears antheridia and archegonia on the same plant but on different branches. <br /> After fertilization the zygote (2n) divides to form the sporophyte which consists of foot, seta and capsule. The basal foot is embedded in the apex of female branch. It absorbs nutrients and provides support for the sporophyte. Inside the capsule haploid spores are produced as a result of meiosis. Thus again the gametophytic phase starts. So the gametophytic phase is the dominant phase of the life cycle of Funaria.

Share Answer Pyrenoids are found in many bryophytes and algae. They are small, spherical bodies found in the cytoplasm of a plant cell. They are rich in proteins and are surrounded by a starch sheath.

Share Answer Gymnosperms show distinct alternation of generations. The sporophytic phase is dominant. The sporphyte is differentiated into root, stem and leaves. So the number of chromosomes in a leaf cell is diploid (2n), (2n = 16). Double fertilization is absent in gymnosperms. The endosperm develops before fertilization directly from the megaspore. So the number of chromosomes in endosperm will be 8(n = 8).

Share Answer Marchanlia is a liverwort in which the sex organs are borne on disc shaped 8-Iobed receptacles borne at the tip of vertical gametophores. Sperms are attracted to opened archegonia by proteins and K+ salts. Fertilization produces a parasitic sporophyte made of foot, seta and capsule. The capsule encloses sporocytes and elaters. These elaters show twisting movements due to spiral bands of thickenings and this leads to liberation and dispersal of spores. In Riccia elaters are absent and in Funaria peristome teeth help in spore dispersal.

Share Answer Bryophytes are land inhabiting or terrestrial plants. They complete their vegetative phase on land but water is necessary for their reproductive phase i.e. for completion of life cycle. So bryophytes are known as amphibians of plant kingdom. <br /> Thallophytes have a plant body that is not clearly differentiated into root, stem and leaves. They do not have vascular tissues and so are always aquatic. Pteridophytes are most primitive vascular plants. They have developed vascular tissues and so they were the first vascular plants on land. <br /> Tracheophyte includes all vascular plants pteridophytes, gymnosperms and angiosperms.

Share Answer Gymnosperms originated about 200 million years ago and were dominant species at that time. However most of the members have become extinct now and only few living forms are known today. There are around 900 living species of this group.

Share Answer Brown algae are the members of the class phaeophyceae. Their chromatopores are ellipsoidal or discoid. They contain chlorophyll a, chl c, P- and c- carotenes and xanthophyll pigments (e.g., lutein, flavoxanthin, violaxanthin). They also contain large amount of a brown pigment fucoxanthin which masks the green colour of chlorophyll pigment. This gives characteristic brown colour to these plants, hence the name brown algae. <br /> The non-motile resting spores of Chlamydomonas contain a red pigment called hematochrome. phycocyanin and phycoerythrin are water soluble pigments found in red and blue-green algae.

Share Answer The division Bryophyta includes three classes Hepaticopsida, Anthocerotopsida and Bryopsida. The members of Hepaticopsida and Anthocerotopsida have a thallose plant body which is dorsiventrally differentiated and dichotomously branched. On the ventral surface unicellular or multicellular rhizoids are present. The member of Bryopsida has a main plant body that has a leafy gametophore made up of an axis having spirally arranged leaves. <br /> The rhizoids are multicellular and branched e.g. Sphagnum, Funaria, Riccia, and Anthoceros. So only few members of bryophytes have leafy gametophytes. Gymnosperms have well developed plant body having root stem and leaves. They do not have rhizoids.