RBSE Class 11 Biology Notes Chapter 3 Plant Kingdom

These comprehensive RBSE Class 11 Biology Notes Chapter 3 Plant Kingdom will give a brief overview of all the concepts.

RBSE Class 11 Biology Chapter 3 Notes Plant Kingdom

→ The artificial system of classification is based on only superficial characters like habit, habitat, morphology etc.

→ “Carolus Linnaeus” regarded as “father of systematic botany” published artificial system based exclusively on floral characters.

→ Natural system of classification is based on the comparison of a large number of permanent characteristics that bring out natural affinities of organisms.

→ “Bentham and Hooker” described the natural system of classification in their book “Genera plantarum”.

 

→ “Phylogenetic system of Classification” is based upon the phylogeny (evolutionary history) of organisms.

→ Cyto taxonomy is based on cytological studies of the cell including the size, structure and number of chromosomes as well as behaviour of chromosomes during meiosis.

→ Chemotaxonomy is based on the proteins and serum analysis and on the chemical constituents of the organisms.

→ Numerical taxonomy involves quantitative assement of similarities and differences in order to make objective assessments.

→ The term ‘Algae’ was coined by Carolus Linnaeus which means ‘sea weeds’.

→ Algae are chlorophyll bearing, simple, thalloid, autotrophic and largely aquatic (both fresh water and marine organisms).

→ The sexual reproduction in algae may be isogamous, anisogamous or oogamous type.

→ The algae are divided into three main classes. Chlorophyceae, Phaephyceae and Rhodophyceae.

→ The plant body of some highly advanced algae can be divided into a root like holdfast, a tubular stipes and leaf like blades.

→ Brown algae contain a large amount of ‘fucoxanthin’ pigment which impart them brown colour.

→ Red algae is red in colour due to the presence of a red coloured pigment R-phycoerythrin.

→ The reserve food material of red algae is floridean starch.

→ The bryophytes are fundamentally terrestrial but they require presence of water for fertilisation so they are regarded as “the amphibians of plant kingdom”.

→ The sex organs in bryophytes are multicellular. The male sex organ is antheridium while female sex organ is called archegonium.

→ The gametophyte of mass occurs in two stages: a filamentous stage called protonema and a leafy stage.

→ In sporophytic plant body of pteridophytes, the leaf like appendages are called sporophylls contain sporangia.

→ In pteridophytes, heterospory and seed habit are considered the steps of evolution.

→ Evolutionarily, pteridophytes are the first terrestrial plants to possess vascular tissues-xylem and phloem.

→ Gymnosperms are called ‘naked seeded plants’ because the seeds are not enclosed inside a fruit.

→ The gymnosperms include world’s tallest tree: Sequoia sempervirens (the giant red wood) measuring about 125 metres in height and 30 metres in girth.

→ Plant belonging to division cycadophyta are commonly called cycads.

→ Because of the over exploitation, most of the cycad species are becoming endangered and, therefore, they have been referred as ‘reptiles of plant kingdom’ or ‘panda of vegetable kingdom’.

→ The Angiosperm are considered most highly evolved and advanced vascular plants.

→ In angiosperms, the seeds (ovules) are enclosed inside the fruits (hollow ovary).

→ The angiosperms are divided into two main classes: dicotyledons and monocotyledons. 

→ The reproductive organs of angiospermic plants are present in flower.

→ A flower may be either staminate (male) or pistilate (female) or bisexual (has both stamen and pistil).

→ Transfer of pollen grain from another to the stigma is called pollination.

→ If the pollen grains are transferred from the another of a flower to the stigma of either same flower (self pollination) or the stigma of other flower (cross pollination).

→ Double fertilisation is a unique feature to all angiosperm.

→ The endosperm provides nourishment to developing embryo.

→ After the double fertilisation, the ovules are ripened into seeds and the ovary develops into the fruit.

→ In haplontic life cycle, the haploid phase is dominant while in diplontic life cycle pattern, the diploid phase is dominant.

→ In haplo-diplontic life cycle pattern, two independent gametophytic and sporophytic phases alternate with each other.

→ Thallophyta: It does not show differentiation of stem leaves, and roots. Plant body is called thallus. Embryo stage is absent. Sex organs are non jacketed and basically unicellular.

→ Cormophytes: The plants with distinction of stem, leaves and roots.

→ Embryophyta: They include all plants that possess an embryo stage in life cycle, and jacketed sex organs.

→ Cryophytes: Dwelling in snow. Some algae colour this snow

• Red snow: Chlamydomotias nivalis, Ulothrix etc.,
• Purple brown snow: Ancylonema,
• Yellow snow: Chlamydomonas flavovirens.

→ Phycocolloid: It is mucopolysaccharide present in and over the wall of brown and red algae like alginic acid (brown algae), agar and carrageenin (red algae).

→ Bryophyta: These are non vascular embryophytes plants,

→ Bryology: Branch of science that deals with the study of bryophyta.

→ Sporogonium: Sporophytes of bryophytes which is parasitic over gametophytic plant body and is mainly meant for producing meiospores.

→ Hornwort: Anthoceros like bryophytes in which the liverworts—like thallus contains embedded sex organs while the sporogonium is aerial, elongated and cylindrical.

→ Elasters: Elongated structures which help in spores dispersal. They have spiral bands of thickening for xerochasy. Elasters are epispore appendages in horsetail.

→ Moss: Leafy bryophyte with radial symmetry, multicellular rhizoids, protonema stage, cluster of sex organs at branch tips.

→ Exoscopic: Embryo in which the apex is towards the tip of archegonium.

→ Endoscopic: Embryo in which the apex is towards the base of archegonium.

→ Sphagnol: Distillate from peat tar which can treat skin disease.

→ Cryptogams: Plants are without seeds e.g., algae, bryophytes and pteridophytes.

→ Phanerogams: Spermatophytes or seed plants like gymnosperms and angiosperms.

→ Tree fern: Fern with upright aerial stem e.g., Cyathaea.

→ Annuals: The plants which live for one season and complete their life cycle.

→ Anemophilous: When pollination takes place by winds.

→ Antheridium: 'Male sex organs of bryophytes and pteridophytes.

→ Archegonium: Female sex organs of bryophytes, pteridophytes and gymnosperms.

→ Carotenoids: A group of pigments comprising carotene and xanthophylls.

→ Carotene: The orange pigment made up of hydrocarbons.

→ Endosperm: The nutritive tissue that provide nourishment to developing embryo in angiosperms.

→ Facoxanthin: A xanthophyll pigment of brown algae.

→ Gametophyte: Gamete producing haploid phase of plant.

→ Sporophyte: Spore producing diploid phase of plant.

→ Monocots: Angiospermic plants with single cotyledon in their seeds.

→ Dicots: Angiospermic plants with two cotyledons in their seeds.

→ Hydrophytes: Plants found in aquatic habitats.

→ Heterospory: Existence of two types of spores i.e., microspores and megaspores.

→ Hypnospores: Under unfavourable conditions, protoplasm may develop thick wall to form hypnospore in some green algae. 

→ Orthotropous: Straight ovule found in gymnosperms and some angiosperms.

→ Perennial: The plants which grow for many seasons.

→ Pollination: Transfer of pollen grain to the stigma.

→ Polyembryony: Formation of many embryoes within single seed.

→ Pyrenoids: Starch storing proteinaceous bodies in some algae.

→ Rhizome: Underground unbranched stem in fern.

→ Siphonaceous: Multinuclear thallus but not divided into cells.