Maharashtra Board 11th Standard Biology Chapter 'Kingdom Plantae'

1. Kingdom Plantae
Biren Daftary

2. Introduction
• Multicellular, eukaryotic organisms with photosynthetic mode of
nutrition are included under kingdom plantae
• These are called as plants & are the main producers on land &
water
• With the help of chlorophyll they synthesize carbohydrates and
release oxygen in air
• Kingdom plantae divided into 2 sub kingdoms: Cryptogamae &
Phanerogamae

3. Cryptogamae (Kryptos: concealed; gamos: marriage)
• Spore producing plants which do not produce seeds & flowers
• Reproduce sexually by gametes but sex organs are hidden
• Include algae, bryophytes & pteridophytes
Phanerogamae (Phaneros: visible)
• Seed producing plants which have special reproductive structures
that are visible
• Commonly called as seed plants
• Include gymnosperms & angiosperms

4. 2.1 SALIENT FEATURES OF MAJOR PLANT
GROUPS (CRYPTOGAMAE)

5. 1. Division Algae
• Mostly aquatic, some terrestrial, some grow on other plants
• Free living & symbiotic
• Vegetative structure (thallus) varies in organization & size e.g.
1. Small, unicellular & microscopic (Chlorella, Chlamydomonas)
2. Multicellular and unbranched filamentous ( Spirogyra)
3. Branched filamentous (Chara)
4. Huge macroscopic (Sea weeds like Sargassum which measure 60m
in length)

7. • Algal cell wall made up of outer ‘pectin’ & inner ‘cellulose’ layer
• Various types of photosynthetic pigments are present
• Essential pigment: Chlorophyll-a (present in all types of algae)
• Accessory pigments: chlorophyll-b, chlorophyll-c, chlorophyll-d,
carotenes, xanthophylls & phycobilins (phycocyanins &
phycoerythrins)
• Reserve food material is starch ( laminarin – starch, mannitol or
floridean – starch)
• Vegetative reproduction occurs by ‘fragmentation’ & cell division

9. • Asexual reproduction by formation of motile or non motile spores
• Sexual reproduction is through formation & fusion of gametes
• Algae life cycle exhibit ‘alternation of generations’ (haploid &
diploid phase in life)
• Depending upon the photosynthetic pigment present, algae are
divided into 3 major groups:
a) Chlorophyceae (green algae)
b) Phaeophyceae (brown algae)
c) Rhodophyceae (red algae)

11. Chlorophyceae (Green algae)
• Main photosynthetic pigments are chlorophyll-a & chlorophyll-b
• Reserve food in the form of starch
• Cell wall mainly made up of cellulose
• Motile cells have 2-8 apical flagella & are found mostly in fresh
water & sometimes in marine & brackish water
• Examples: Chlamydomonas, Spirogyra, Chara

13. Phaecophyceae (Brown algae)
• Main photosynthetic pigments are chlorophyll-a, chlorophyll-c &
fucoxanthin
• Mannitol & laminarin are reserved starch food
• Cellulose & algin present in cell wall
• Motile spores are biflagellated with 2 unequal lateral flagella
• These algae commonly occur in marine water & brackish water &
some in fresh water
• Examples: Ectocarpus, Sargassum, Fucus (some used as food)

14. Sargassum

15. Rhodophyceae (Red algae)
• Main photosynthetic pigments are chlorophyll-a, chlorophyll-d &
phycoerythrin
• Reserve food material in the form of floridean starch
• Cell wall = pectin + cellulose + other carbohydrates
• Motile cells are absent, red algae are found in marine & brackish
water and rarely in fresh water
• Examples: Chondrus, Gelidium, Polysiphonia (Agar is obtained from
red algae)

16. Chondrus
Gelidium
Polysiphonia

17. 2. Division Bryophyta
• Mostly terrestrial plants depending on water for external
fertilization & completion of life cycle (amphibious plants)
• Include about 960 genera & 24000 species
• Grow in shady & moist places (moist walls, damp rocks, etc.)
• They show either thalloid or leafy plant body
• True roots are absent but ‘rhizoids’ are present. Rhizoids absorb
water & minerals & help in fixation of thallus to the substratum

18. • Vascular tissues are absent, however a conducting strand of a few
thick walled cells is present in mosses
• Bryophytes show ‘heteromorphic alternation of generation’
a) Gametophyte phase is green, dominant, independent & haploid
b) Sporophyte phase is non-green, recessive, dependent & diploid
• Vegetative reproduction is by special structures called ‘tubers’ &
‘gemmae’
• Asexual reproduction is by spore formation & sexual reproduction is
by formation & fusion of gametes
• Bryophytes are divided into 2 groups: liverworts & mosses

21. Liverworts
• Lower members of Bryophyta having prostrate plant body
• Found in moist & shady places
• Thallus is dorsiventral, prostrate & with unicellular rhizoids
• Some of them have stem like axis & leaf like appendages
• Vegetative reproduction is by fragmentation or formation of
gemmae ( each gemma develops into young plant on separation)
• Sexual reproduction is by formation of male & female sex organs on
same or different plants

22. • After fertilization, a sporophyte (diploid) is formed which contains
haploid spores produced by meiosis
• This haploid spores on germination produce haploid young plants
called as gametophytes
• Examples: Riccia, Marchantia

23. Riccia
Marchantia

24. Mosses
• Higher members of Bryophyta which have an erect plant body
• The gametophyte phase has 2 stages:
a) Protonema stage: (Juvenile gametophyte)
• Prostrate, green, branched and filamentous
• It bears many buds & leafy stage is produced from each bud
• Hence protonema helps in vegetative propagation
a) Leafy stage:
• It has an erect, slender main axis & a branch bearing spiral leaf like
structures.
• It is fixed in soil by multicellular rhizoids

25. • During sexual reproduction, antheridia & archegonia are produced
as sex organs in clusters at the tip of the main axis
• The clusters of sex organs are hidden by a whorl of leafy
appendages
• Zygote gives rise to a well developed sporophyte with foot, seta &
capsule
• Haploid spores formed by meiosis are released by dehiscence of
capsule
• Examples: Funaria, Polytrichum

27. Funaria

28. 3. Division Pteridophyta
• First vascular plants on land with true roots, stem & leaves
• This group has 400 genera & 10500 species
• Plants have pinnate leaves
• Pteridophytes are also called as ‘vascular cryptogams’ and are the
only cryptogams with vascular tissue
• They do not produce flowers, fruits & seeds

29. • Pteridophytes are terrestrial, small, annual or perennial & grow a
lot in moist & shady places e.g. Ferns
• Pteridophytes may be aquatic (Azolla), xerophytic (Equisetum) or
epiphytic (Lycopodium)
• They show ‘heteromorphic alternation of generation’. Sporophyte is
diploid, dominant, autotrophic, independent & is differentiated into
root, stem and leaves
• Primary root is short lived & is replaced by adventitious roots,
whereas the stem may be underground or aerial
• Leaves may be scaly (Equisetum), simple & sessile (Lycopodium) or
large & pinnately compound (Ferns)

30. • Xylem consists of only tracheids & phloem consists of only sieve
cells
• Secondary growth is not seen because of absence of cambium
• Sporophyte shows asexual reproduction by producing spores
• Gametophyte develops from the spores and is haploid, recessive
but independent & reproduces sexually to form a diploid
sporophyte
• Pteridophytes are of 2 types: heterosporous & homosporous
• Spores are produced I special multicellular structures called
‘sporangia’

32. Apogamy
• Development of sporophyte without fusion of male & female
gametes.
• Arises directly from gametophyte, hence the sporophyte is haploid
Apospory
• Development of the gametophyte from any cell of the sporophyte
other than spores
• Hence such a gametophyte is diploid

33. Fern: Alternation of generations

34. 2.1 SALIENT FEATURES OF MAJOR PLANT
GROUPS (PHANEROGAMAE)

35. Division: Gymnospermae
• Plants with naked seeds
• They are the simpler members of phanerogams without ovary
• Term ‘Gymnosperm’ first used by ‘Theophrastus’ in 300 B.C. in his
book “Enquiry into plants”
• 70 genera & 725 species ( In India there are 16 genera & 53 species)
• Most are evergreen perennial trees or shrubs
• These are vascular plants having xylem with tracheids & phloem
with sieve cells

36. • Non-flowering plants producing naked seeds (fruits are absent)
• Show heteromorphic alternation of generations
a) Sporophyte is diploid, dominant, autotrophic & independent
b) Gametophyte is haploid, recessive and dependent. Gametophyte
is very much reduced & exists inside the sporophyte
• Sporophyte is differentiated into roots, stem & leaves
• Well developed tap root system is present
• Coralloid roots are present in Cycas which show association with
blue-green algae (cyanobacteria)
• Pinus shows association with endophytic fungi called mycorrhizae

38. • Stem is mostly erect, aerial, solid & cylindrical
• In Cycas it is usually unbranched, while in conifers it is branched
• Leaves are dimorphic. Foliage leaves are green & simple, needle like
or pinnately compound. Scaly leaves are small, membranous &
brown
• Secondary growth present because of cambium
• Gymnosperms are heterosporous (microspores/megaspores)
• Spores - sporangium - leaf like sporophyll - cone or strobillus

40. • Pollination in gymnosperms is anemophilous (wind) & direct
(pollen grain received directly in pollen chamber of ovule)
• Fertilization is through a pollen tube, hence the process is also
called as siphonogamy
• Vegetative reproduction takes place with the help of bulbils
• Some gymnosperms are called as living fossils because it is found
more in fossilized form than living form
• Gymnosperms vary greatly in size
a) Sequoia sempervirens is tallest at 366 feet (coast redwood of
California)
b) Taxodium mucronatum has diameter of 125 feet
c) Zamia pygmaea is smallest gymnosperm of 25cm only

41. Pollen chamber

43. Ginkgo biloba fossil
Ginkgo biloba plant

44. Coast Redwood
Zamia pygmaea
Taxodium mucronatum

45. Division: Angiospermae
• Most advanced division which are the flowering plants
• Seed are enclosed within the ovary inside the fruit
• Highly evolved pants adapted primarily to terrestrial habitat
• Vary in size (Wolffia is smallest about 1mm & Eucalyptus above
100m)
• Plant body differentiated into root, stem & leaves
• It has flowers, fruits, seeds & vascular tissues are well developed
• Xylem shows vessels & phloem shows companion cells & sieve
tubes

46. • Angiosperms show ‘heteromorphic alternation of generations’
a) Sporophyte is diploid, dominant, autotrophic & independent
b) Gametophyte is recessive, haploid & dependent on sporophyte
• These plants are ‘heterosporous’
a) Microspores – Microsporangia – Microsporophylls (Stamens)
b) Megaspores – Megasporangia – Megasporophylls (Carpels)
• Essential whorls & accessory whorls form the flower
• Pollination is ‘indirect’ (Pollen grains fall on the stigma first)
• Angiosperms show double fertilization (1 male gamete fuses with
egg cell to form embryo, 2nd male gamete fuses with secondary
nucleus to form endosperm)

47. • Ovule changes to seed & ovary ripens to form fruit

48. Class: Dicotyledonae
• 2 cotyledons in embryo
• Stem is heavily branched with a tap root system
• Leaves show reticulate venation
• Flowers show tetra or pentamerous symmetry
• Secondary growth is found
• Vascular bundles of stem are conjoint, collateral & open
• Examples: Sunflower, China rose

49. Class: Monocotyledonae
• Single cotyledon in embryo
• Stem is less branched with an adventitious root system
• Leaves show parallel venation along with a sheath base
• Flowers are generally trimerous
• Vascular bundles are conjoint, collateral & closed
• Secondary growth is absent
• Examples: Maize & Jowar

51. Plant life cycles
• Includes 2 phases, sporophyte (2n) & gametophyte (n)
• Cells of sporophyte undego meiosis to form haploid cells
• Haploid cells undergo mitosis to form haploid gametophyte
• Gametophyte produces gamete which fertilizes with opposite
gamete to form diploid sporophyte
• This sporophytic & gametophytic generations occur alternately in
life cycle of plants & hence called as ‘alternation of generations’

52. • Distinct alternation of generations is observed in bryophytes &
Pteridophytes
• In gymnosperms & angiosperms, gametophyte is much reduced &
occurs inside the sporophyte
• In algae, life cycle is called as haplontic, diplontic or haplo-diplontic
depending