Classification Of Plants

A.Thallophyta

Explanation:

Thallophyta are found mostly in water some in fresh, saline water soft and fibre like body due to absence of mechanical and conducting elements and presence of cellulose cell wall.

B. Bryophyta

Explanation:

Bryophytes lack vascular tissue system ,true roots, leaves, stems.

Found on most places still they require water for transfer of sperms for fertilization hence called amphibians of plant kingdom.

C. Spore, Zygote

Explanation:

Pteridophytes have well developed vascular tissues and leaves,

stems, roots but these plants produce neither flowers nor seeds also called seed less vascular cryptograms. Sporophyll leaves have sporangia which produce spores. Formation and fusion of male and female gamete forms zygote this

further produces well differentiated multicellular sporophyte.

D. Gymnosperms

Explanation:

Spores are produced within sporangia present on sporophyll,

which are leaves which form compact structures called cones these are male and female. Few species of gymnosperms like pinus have both male and female on same tree but located far apart this can be called dioecious and few species of cycas where male and female are produced on different plant can be termed as

monoecious.

(A) The characteristics of subkingdom phanerogamae.

1. Phanerogams means visible gametes. Flowering or seed bearing plants, most developed plants with roots, stem, leaves.

2. These are divided into two main groups –

A)Gymnosperms –

1. Gymnos means naked and sperm means seed.

2. Seeds are naked therefore they do not bear true fruit.

3. Evergreen, perennial, woody found mainly on hills.

4. Some plants male and female cones (flowers) on same plant are called dioecious eg: pinus whereas in some on different plants called monoecious eg: cycas.

B) Angiosperms –

1. Angios means cover and sperm means seed.

2. Seeds are covered as true ovary is found. Pollen Grains and ovules are developed in specialized structures called flowers.

3. These are divided into two classes: dicotyledons and monocotyledons.

4. Dicotyledons are characterized by having two cotyledons in their seeds while the monocotyledons have only one.

Difference between monocots and dicots-

Monocots differ from dicots in various categories leaves, stem, roots ,flowers.

Ornamental flowers ferns –

● Ornamental flowers ferns belong to division pteridophytes.

● Being a pteridophyta it have differentiated stem, root, leaves and well developed vascular system.

● Leaves of Fern are large called microsporophyll.

● Ferns have wide variety of habitats mountains, dry deserts, water or open fields.

● Ferns are used in food, horticulture etc

● Fern includes pteris, adiantum, equistem, selaginella.

SPIROGYRA

A green-coloured algae commonly found in stagnant freshwater bodies is known as spirogyra. Mainly, spirogyra is slimy and has filament to touch in which the filaments are present in the cylindrical cells placed one above the Also there is a single large vacuole in each cell.

Characteristics of bryophytes -

1. This group of plants is also called amphibians of plant kingdom.

2. These plants are thalloid, multicellular, autotrophic.

3. Bryophytes grow in moist soil but requires water for transfer of male gametes to female.

4.They have leaf like, stem like ,root like modification.

MARCHANTIA

1. Found mostly on silty clay or moist soil.

2. Marchantia show differentiation in two layers upper assimilatory region and

lower storage.

3. Thallus features has tiny cup like structures called gemma cups used for asexual reproduction.

4. Antheridia and archegonia are born on special stalks antheridiophores and archegoniophores. These are separate thalli therefore plant is dioecious.

5. Asexual reproduction occurs by gemmae discoid clumps of cells.

FUNARIA

1. Plant is small erect, small & branched.

2. Differentiated into rhizoids, axis, leaves (simple ,small, spirally arranged)

3. Asexual method takes place to give rise to primary protonema, secondary protonema.

4. It consists of multicellular colourless branched rhizoids.

FERN

1. Fern belong to pteridophytes therefore they have vascular tissues well developed roots, stem, leaves.

2. Fern stem is often referred to as rhizomes.

3. Green, photosynthetic part of plant is technically megaphylly.

4. Fern species can be found many habitats as remote mountains, dry dessert Some species are lycopodium, selaginella, equisetum.

5. Fern are used as ornamentals, food etc.

SPIROGYRA

1. A green-colored algae commonly found in stagnant freshwater bodies is known as spirogyra. Mainly, spirogyra is slimy and has filament to touch in which the filaments are present in the cylindrical cells placed one above the Also there is a single large vacuole in each cell.

One can differentiate in monocot and dicot based on below observations-

Criteria used for classification of plants are-

● Presence or absence of organs in different plant division (Thallophytic, ,bryophyte, pteridophytes, gymnosperms, angiosperms) is the first criterion for classification of plants.

● Presence or absence of several conducting tissues for conduction of water and food, bryophytes do not possess whereas pteridophyta, gymnosperms, angiosperms possess.

● Development of seed as pteridophytes do not have seed whereas gymnosperms and angiosperms have seeds.

● Seeds are developed without seed coat in gymnosperms (naked)and or with seed coat in angiosperms(covered).

● The number of Seed coats in monocot is one cotyledon and dicot have two.