1- Phylogeny-Evolutionary history of organism.
2- Zoospores-Motile spores with flagella.
3-Gametophyte-Haploid stage of plant, producing gametes.
4-Sporophyte-Diploid stage of plants producing spores.
5-Archegonium-Female reproductive structure.
6-Antheridium-Male reproductive structure.
7-Megasporangium-The structure which bears megaspores.
8-Sporophyll-Leaf bearing sporangia producing spores.
- | Numerical taxonomy | - | based on several features compared collectively by computer. | ||
- | Cytotaxonomy | - | based on cytological features. | ||
- | Chemotaxonomy | - | based on chemical constituent. | ||
Algae– | |||||
- | Group of chlorophyllous, simple, thalloid plants. | ||||
- | Largely aquatic, grow on soil, stone, wood etc or symbiotic. | ||||
- | Unicellular to large filamentous. |
Economically useful as-
a) Large photo synthesiser, release 02 .
b)Food for aquatic animals, humans.
c)Produce Algin (Brown algae), carrageen (red algae), agar (gelidium, gracilaria)
- Chlorella, Spirullina- in space travel as protein rich food.
Chlorophyceae | Phaeophyceae | Rhodophyceae |
- Green algae chlorophyll a&b dominant. | -Brown algae. - Xanthophyl, Fucoxanthin dominant others are chl. a, c cartenoid. - Simple branched filamentous to profusely branched large body. - Gelatinous coating on cell wall. - Stored food Mannitoland Laminarin.Reproduction - Vegetative by fragmentation Asexual By biflagellate (lateral) zoospores. Sexual by gametes(Iso, Aniso and Oogamy). - eg. Laminaria,Sargassum. | - phycoerythrin (dominant) and others chlorophyll a and d. - Marine on surface or in great depths, multi cellular. - Stored food – Floridean starch. -Red algae - Reproduction Vegetative by fragmentation Asexual by non motile spores Sexual by oogamy. - eg. Gracilaria, Gelidium |
Bryophytes ( Amphibians of plant Kingdom) –
Group of autotrophic plants with thallus having true roots, stem and leaves with multi cellular sex organs.
Occurs on damp, humid and shaded soil.
Root like rhizoids present.
-Main plant body gametophyte bears Antheridia and Archegonia. Biflagellate antherozoids produced from Antheridium and reach through water to egg in Archegonium.
-Zygote forms sporophyte which produces haploid spores to give rise to new plants.
Types of Bryophytes
Liverworts | Mosses |
1.Thallus dorsiventrally flattened (Liver shaped), leafy members with leaf like appendages. 2. Asexual reproduction by fragmentation , gemmae formation. 3.Sexual reproduction - antheridia and archegonia produced. 4. Antherozoids fuse with egg to form zygote which give rise to Sporophyte. 5. Sporophyte - with foot, seta & capsule. 6. Spores give rise to new plant (gametophyte). eg. Riccia, Marchantia etc. Marchantia | - Thallus : Two stages (gametophyte) – (a) Thread like Protonema (b)erect Leafy stage. 1. Reproduction :Vegetative by Fragmentation of protonema & Sexual by antherozoids &egg. 2. Zygote forms Sporophyte with foot, seta &capsule. Funaria |
Pteridophyte: | |||
- | Group of first terrestrial plants having vascular tissue viz. Xylem & Phloem. | ||
- | True stem, root & leaf. | ||
- | Found on damp, shady places. Sporophyte makes main plant body. | ||
- | Sporophylls of Sporophyte bear sporangia (sori) onventral side producing haploid spores. | ||
- | spores give rise to Prothallus which is leafy & autotrophic. | ||
- | Prothallus bears sex organs – male – Antheridium and female- Archegonium. | ||
- | Fertilisation leads into zygote formation which produces diploid Sporophyte. | ||
Heterospory and Seed habit: | |||
- | Two types of spores Microspore and Megaspore are produced in some members viz. Selaginella, Salvinia. | ||
- | called Heterospory. | ||
- | Heterospory is considered as begining of seed habit in terrestrial plants. | ||
eg. Pteris, Dryopteris etc. | |||
GYMNOSPERMS | |||
- | Medium sized trees and shrubs. | ||
- | Main plant body Sporophyte | ||
- | In some members roots may have fungal association called Mycorrhiza. | ||
-bilus. | |||
- | Microspore i.e. pollens reaches to ovules.Pollen tubes help to transfer male gametes up to egg of archegonia present in female gametophyte of ovule. | ||
Zygote develops in an embryo inside seed | |||
- | e.g. Cycas, Pinus ,Cedrusetc. | ||
ANGIOSPERMS | |||
Large no. of plants in varied habitats, small microscopic plants (Wolfia) to large trees | |||
- | Group of plants having covered seeds in fruits. | ||
- | Produce flowers having reproductive organs. | ||
- | Most evolved plants. |
-Androecium is male part and one unit is stamen.
-Gynoecium is female part and one unit is carpel and has ovules.
-Ovule bears embryo sac.
-Embryo sac is seven celled and has Egg
01 – haploid. Synergids
02 – haploid. Antipodals
03 - haploid. Secondary nucleus
04 – diploid.
-Reproduction by vegetative and sexual methods.
-In sexual reproduction pollens shed off and reach to stigma of Gynoecium by pollination.
-Pollen germinates to form pollen tube with two male gametes and one tube nucleus.
-One gamete fuses with egg (Syngamy) and other with secondary nucleus to form PEN (primary endosperm nucleus). The whole process is called Double fertilization.
-Zygote forms embryo and PEN forms Endosperm in ovule which changes into seed inside fruit.
-Ovary wall changes into Pericarp (fruit wall).
-Alternation of generation occurs.
Plant life cycle and alternation of Generation –
-Alternate stages of haploid (n) and Diploid (2n) phase in life cycle of plants.
- Three Patterns -
Haplontic | Diplontic | Haplodiplontic |
- Dominating phase haploid (n). -only zygote diploid (2n). -Haploid spores form the main plant bodyeg. Algae viz. Ulothrix,Spirogyra etc. | -Dominating phase diploid (2n). -Haploid phase only in single cell or few celled gametophyte. -Zygote forms embryo which forms Sporophyte (main plant body). eg. Gymnosperms& Angiosperms | -Intermediate i.e.haploid & diploid stages equal. -Gametophyte & Sporophyte stages both may be free living.eg. Bryophytes & Pteridophyte. |
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