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State Board · Class 11 · Biology

Lesson 3: Kingdom Plantae

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Kingdom Plantae and Thallophyta

Link to Std 9–10

This is the detailed stage of the plant classification of Std 9–10 (algae, bryophytes, pteridophytes, naked- and covered-seed plants).

From daily life

A green film on a damp wall in the rains and flowering shrubs in a garden are both plants, yet one group has no root, stem or leaf and the other has flowers and seeds.

Simple definition

Phanerogamae are seed plants with visible reproductive parts; Cryptogamae reproduce by spores, no flowers or seeds (concealed sex organs). Thallophyta (algae) have a thalloid body not differentiated into root, stem and leaves.

Classification chart of Kingdom PlantaeKingdom PlantaeCryptogamae (no seeds)Phanerogamae (seeds)Thallophyta(algae)BryophytaPteridophytaGymnospermaeAngiospermaeDicot | MonocotNon-vascular:Thallophyta, BryophytaVascular: Pteridophyta onwards

In the figure : Chart: Cryptogamae → Thallophyta, Bryophyta, Pteridophyta; Phanerogamae → Gymnospermae, Angiospermae.

Rule 1 : Classification of the plant kingdom — Basis: seeds, vascular tissue, body differentiation. Cryptogamae: Thallophyta, Bryophyta (non-vascular), Pteridophyta (vascular). Phanerogamae: Gymnospermae, Angiospermae.

  • Easy : Phaneros = visible; kryptos = hidden.
  • Medium : Which cryptogams are vascular? Pteridophyta.
  • Exam-type (CET) : Why is a fern vascular but not a phanerogam? It produces no seeds.

Rule 2 : Features of Thallophyta — Mostly aquatic (fresh/marine); thalloid body; unicellular (Chlorella, Chlamydomonas) to filamentous (Spirogyra, Chara); Sargassum over 60 m. Starch reserve; pyrenoids on chloroplast; vegetative, asexual and sexual reproduction. Pigments decide the classes.

  • Easy : Chlorella is protein-rich and used as food by space travellers.
  • Medium : Chlamydomonas is microscopic and Sargassum huge, both algae: thalloid body, chloroplast, aquatic.
  • Exam-type (CET) : Algae show alternation of generations: dominant haploid, reduced diploid phase.
Remember

Cryptogamae = spores; Phanerogamae = seeds. Thallophyta lack root, stem and leaf.

Common mistake and CET trap

‘Fern is a phanerogam’ is wrong. Trap: ‘Bryophytes have vascular tissue’ is wrong.

Shortcut

Memory clue : "T-B-P: Thallo → Bryo → Pterido (simple → complex)".

Spot the difference

GroupBodyVascular tissue
ThallophytaThallusAbsent
BryophytaThalloid/leafy, rhizoidsAbsent
PteridophytaRoot, stem, leafPresent

Practice questions

Easy
  1. 1What does cryptogamae mean?
  2. 2Two groups of phanerogamae?
  3. 3What is the body of Thallophyta like?
Medium
  1. 4Give one example each of unicellular, filamentous and large algae.
  2. 5Why are Chlamydomonas and Sargassum in one group?
  3. 6Why is fern not a phanerogam?
Challenging
  1. 7Where is a pyrenoid and what does it do?
  2. 8Name non-vascular and vascular cryptogams.
Show answers (try them yourself first)
  1. 1Plants with hidden sex organs and no seeds.
  2. 2Gymnospermae, Angiospermae.
  3. 3Thalloid; not differentiated into root, stem, leaf.
  4. 4Chlorella; Spirogyra; Sargassum.
  5. 5Both have a thallus, chloroplast and aquatic life; both are algae.
  6. 6It has no seeds or flowers; reproduces by spores.
  7. 7On the chloroplast; stores starch.
  8. 8Non-vascular: Thallophyta, Bryophyta; vascular: Pteridophyta.

Green and brown algae

From daily life

The green scum on a pond is green algae; the long dark-brown ribbons washed ashore at the beach are brown algae (kelp).

Simple definition

Chlorophyceae: mostly fresh water, chloroplast with Chl a, b, true starch, cellulose wall. Phaeophyceae: mostly marine, Chl a, c and fucoxanthin, reserve mannitol and laminarin, body of holdfast-stipe-frond.

Chlamydomonas, Spirogyra and LaminariaChlamydomonasCup-shaped chloroplast + pyrenoid, 2 flagellaSpirogyraFilamentous; spiral chloroplastLaminaria (brown)frondstipeholdfastGreen: Chl a, b; true starch; cellulose wallBrown: Chl a, c + fucoxanthin; mannitol, laminarinWall: cellulose + fucans + algin

In the figure : From left: Chlamydomonas (unicellular), Spirogyra (filamentous), Laminaria (holdfast, stipe, frond).

Rule 1 : Chlorophyceae (green algae) — Body unicellular, colonial or filamentous; chloroplast shapes: discoid, cup, reticulate, ribbon, spiral. Examples: Chlamydomonas, Spirogyra, Chara, Volvox, Ulothrix.

  • Easy : Spirogyra has a spiral ribbon-shaped chloroplast.
  • Medium : Chlamydomonas has a cup-shaped chloroplast + pyrenoid and two flagella.
  • Exam-type (CET) : Chara shows oogonium (eggs) and antheridium (sperms) as sex organs.

Rule 2 : Phaeophyceae (brown algae) — Body: holdfast (anchor), stipe (stalk), frond (leaf-like photosynthetic part). Wall: cellulose + fucans + algin. Examples: Laminaria, Sargassum, Fucus, Ectocarpus. Used as food and for hydrocolloids; kelps can reach 100 m.

  • Easy : Frond photosynthesises; holdfast grips the rock.
  • Medium : Fucoxanthin gives the brown colour.
  • Exam-type (CET) : Brown algae store mannitol and laminarin (not true starch).
Remember

Green = Chl a,b + starch; brown = Chl a,c + fucoxanthin + mannitol/laminarin.

Common mistake and CET trap

Brown algae are mostly marine, not fresh water. Trap: ‘Chlorophyceae have Chl d’ is wrong.

Shortcut

Memory clue : "Green = true Starch; Brown = Mannitol + laminarin".

Spot the difference

PointChlorophyceaePhaeophyceae
PigmentsChl a, bChl a, c, fucoxanthin
Reserve foodTrue starchMannitol, laminarin
ExampleSpirogyra, CharaLaminaria, Fucus

Practice questions

Easy
  1. 1Pigments of green algae?
  2. 2Body parts of brown algae?
  3. 3Chloroplast shape in Spirogyra?
Medium
  1. 4Cell wall of Phaeophyceae?
  2. 5Two examples of brown algae and one use.
  3. 6Two differences between green and brown algae.
Challenging
  1. 7Why is a holdfast needed?
  2. 8Which sex organs are seen in Chara?
Show answers (try them yourself first)
  1. 1Chlorophyll a and b.
  2. 2Holdfast, stipe, frond.
  3. 3Spiral, ribbon-like.
  4. 4Cellulose, fucans, algin.
  5. 5Laminaria, Sargassum; food/hydrocolloids.
  6. 6Pigments (a,b vs a,c + fucoxanthin); reserve food (starch vs mannitol/laminarin).
  7. 7To anchor the alga to rock against waves in the sea.
  8. 8Oogonium and antheridium.

Red algae and comparison of algal classes

From daily life

Agar-agar used in jellies and as a tissue-culture medium comes from red algae.

Simple definition

Rhodophyceae: marine and fresh water; Chl a, d and phycoerythrin; Floridean starch; wall of cellulose + pectin; thalloid body.

Comparison of green, brown and red algaeChlorophyceaeGreenChl a, bTrue starchCelluloseFresh waterPhaeophyceaeBrownChl a, c + fucoxanthinMannitol, laminarinCellulose + alginMarineRhodophyceaeRedChl a, d + phycoerythrinFloridean starchCellulose + pectinMarine + freshColourPigmentsReserve foodCell wallHabitatRed algae yield agar-agar (tissue-culture medium)

In the figure : Differences among the three algal classes: colour, pigments, reserve food, wall, habitat.

Rule 1 : Features of Rhodophyceae — Red colour due to phycoerythrin; occur even in deep sea. Examples: Chondrus, Batrachospermum, Porphyra, Gelidium, Gracilaria, Polysiphonia. Agar-agar comes from Gelidium and Gracilaria.

  • Easy : Red alga gets its colour from? Phycoerythrin.
  • Medium : Solidifying agent in tissue-culture medium: agar-agar.
  • Exam-type (CET) : Floridean starch is found in which algae? Red.

Rule 2 : Comparing the three classes — Accessory pigments of algae: xanthophyll, fucoxanthin, phycoerythrin, phycobilin. Classes are separated by pigments, then by reserve food and wall.

  • Easy : Cellulose + pectin = red; cellulose + algin = brown; cellulose = green.
  • Medium : Chl d occurs in which algae? Red (Rhodophyceae).
  • Exam-type (CET) : ‘Laminarin’ is reserve food of which algae? Brown.
Remember

Red = Chl a,d + phycoerythrin; agar-agar; Floridean starch.

Common mistake and CET trap

Do not mix colour and pigment. Trap: ‘fucoxanthin = red alga’ is wrong (brown).

Shortcut

Memory clue : "R = Red + eRythrin (phycoerythrin)".

Spot the difference

ClassPigmentsReserve foodWall
ChlorophyceaeChl a, bStarchCellulose
PhaeophyceaeChl a, c, fucoxanthinMannitol, laminarinCellulose, algin
RhodophyceaeChl a, d, phycoerythrinFloridean starchCellulose, pectin

Practice questions

Easy
  1. 1Agar-agar comes from which algae?
  2. 2Pigment of red algae?
  3. 3In which algae is Floridean starch?
Medium
  1. 4Name the three algal classes.
  2. 5Two examples of red algae.
  3. 6Wall difference between brown and red algae?
Challenging
  1. 7Complete: reserve food and wall of Chlorophyceae.
  2. 8Two economic importances of algae.
Show answers (try them yourself first)
  1. 1Red algae (Gelidium, Gracilaria).
  2. 2Phycoerythrin (with Chl a, d).
  3. 3Rhodophyceae.
  4. 4Chlorophyceae, Phaeophyceae, Rhodophyceae.
  5. 5Porphyra, Gelidium (any).
  6. 6Brown: cellulose + algin; red: cellulose + pectin.
  7. 7Starch; cellulose.
  8. 8Food (Chlorella, kelp); agar-agar; hydrocolloids.

Bryophyta

From daily life

A velvety green layer appears on rocks and bricks in the rains; mosses bind soil and help make soil from rock.

Simple definition

Bryophyta (bryon = moss) are mostly terrestrial but need water for fertilisation – the ‘amphibians of the plant kingdom’; thalloid or leafy body; root-like rhizoids; no vascular tissue.

Funaria (moss): gametophyte and sporophyteCapsule (spores)setafootleaf-like phylloidcauloid (main axis)rhizoidsSporophyte(2n; short-lived, dependent)Gametophyte(n; dominant, independent)Funaria (moss)

In the figure : Funaria: rhizoids at the base, leaf-like phylloids and main axis, seta and capsule (sporophyte) on top.

Rule 1 : Two groups of bryophytes — Liverworts (Hepaticeae): flat thallus, unicellular rhizoids; e.g. Riccia, Marchantia; hornworts (Anthoceros). Mosses (Musci): erect body, multicellular rhizoids; gametophyte = protonema + leafy stage; e.g. Funaria, Polytrichum, Sphagnum.

  • Easy : Riccia and Marchantia = liverworts; Funaria = moss.
  • Medium : Rhizoids unicellular or multicellular? Liverworts: unicellular; mosses: multicellular.
  • Exam-type (CET) : Protonema is the juvenile gametophyte; buds on it make the leafy stage.

Rule 2 : Life cycle and economic importance — Gametophyte (n) is dominant, photosynthetic, independent; sporophyte (2n) is short-lived, partly/wholly dependent on it. Uses: Sphagnum gives peat (fuel), moss as water-holding packing, soil binding, rock decomposition.

  • Easy : The Funaria capsule makes spores = sporophyte.
  • Medium : Sphagnum = peat; packing for live material.
  • Exam-type (CET) : ‘Why called amphibians?’ They need water for fertilisation.
Remember

Bryophyta: gametophyte dominant; sporophyte dependent; no vascular tissue; about 960 genera, 25,000 species.

Common mistake and CET trap

‘Dominant sporophyte’ belongs to Pteridophyta, not Bryophyta. Trap: calling rhizoids ‘true roots’ is wrong.

Shortcut

Memory clue : "Bryo = Boss gametophyte (Gametophyte is the Boss)".

Spot the difference

PointLiverwortsMosses
BodyFlat thallusErect, leafy
RhizoidsUnicellularMulticellular
ExampleRiccia, MarchantiaFunaria, Sphagnum

Practice questions

Easy
  1. 1Why are bryophytes ‘amphibians of plants’?
  2. 2Function of rhizoids?
  3. 3Name one liverwort and one moss.
Medium
  1. 4What is protonema?
  2. 5Which phase dominates in bryophytes?
  3. 6Two uses of Sphagnum.
Challenging
  1. 7How do mosses prevent soil erosion?
  2. 8A capsule belongs to which generation?
Show answers (try them yourself first)
  1. 1They are terrestrial but need water for fertilisation.
  2. 2Absorb water and minerals; anchor the thallus.
  3. 3Marchantia; Funaria.
  4. 4The filamentous, branched juvenile gametophyte of moss.
  5. 5Gametophyte (n).
  6. 6Peat (fuel); packing material.
  7. 7Dense mats bind the soil.
  8. 8Sporophyte (2n).

Pteridophyta

From daily life

A garden fern has no flowers or fruits but brown dots under its leaves – clusters of spores.

Simple definition

Pteridophyta (pteron = feather) are the first vascular land plants with true roots, stem and leaves, the only vascular cryptogams. The sporophyte (2n) is dominant.

Parts of a fernrhizomeadventitious rootssori (spore clusters)pinnate leaves (macrophylls)Dominant vascular sporophyte(tracheids + sieve cells)

In the figure : Nephrolepis (fern): rhizome, adventitious roots, pinnate leaves and sori.

Rule 1 : Structure — Primary root short-lived, replaced by adventitious roots. Leaves small microphylls (Selaginella) or large macrophylls (Nephrolepis). Xylem has only tracheids and phloem only sieve cells; no cambium, hence no secondary growth.

  • Easy : Fern leaves: pinnate macrophylls.
  • Medium : Why doesn't a pteridophyte thicken? It has no cambium.
  • Exam-type (CET) : Equisetum has scale leaves; Lycopodium has simple sessile leaves.

Rule 2 : Classes and examples — Psilopsida (Psilotum), Lycopsida (Selaginella, Lycopodium), Sphenopsida (Equisetum), Pteropsida (Dryopteris, Pteris, Adiantum). Habitats: Azolla, Marsilea aquatic; Equisetum xerophytic; Lycopodium epiphytic. Uses: medicine, soil binders, ornamentals.

  • Easy : Aquatic pteridophyte: Azolla or Marsilea.
  • Medium : Xerophytic pteridophyte: Equisetum.
  • Exam-type (CET) : Late Paleozoic = Age of Pteridophytes.
Remember

Pteridophyta = true root, stem, leaf; vascular; no seeds; about 400 genera, 11,000 species.

Common mistake and CET trap

‘Pteridophytes show secondary growth’ is wrong. Trap: ‘xylem has vessels’ is wrong (only tracheids).

Shortcut

Memory clue : "Pterido = Pinnate = feather-like".

Spot the difference

PointBryophytaPteridophyta
Dominant phaseGametophyteSporophyte
Vascular tissueAbsentPresent
True rootsNo (rhizoids)Present

Practice questions

Easy
  1. 1What does pteron mean?
  2. 2Dominant phase of pteridophytes?
  3. 3An example of a fern.
Medium
  1. 4One example each of microphyll and macrophyll.
  2. 5Why no secondary growth in pteridophytes?
  3. 6One example from each of four classes.
Challenging
  1. 7Why are pteridophytes called vascular cryptogams?
  2. 8Two differences between Bryophyta and Pteridophyta.
Show answers (try them yourself first)
  1. 1Feather.
  2. 2Sporophyte (2n).
  3. 3Nephrolepis / Adiantum.
  4. 4Selaginella; Nephrolepis.
  5. 5Cambium is absent.
  6. 6Psilotum, Selaginella, Equisetum, Pteris.
  7. 7No seeds but have vascular tissue.
  8. 8Dominant phase: gametophyte vs sporophyte; vascular tissue: absent vs present.

Gymnospermae and Angiospermae

From daily life

A pine cone and a mango fruit: in one the seed is exposed, in the other it is inside the fruit – the main difference between these groups.

Simple definition

Gymnospermae (gymnos = naked) have naked seeds, mostly evergreen trees/shrubs. Angiospermae (angios = vessel) are the most advanced flowering plants; seeds are enclosed within the fruit (ovary). Two classes: Dicotyledonae and Monocotyledonae.

Gymnosperm and angiosperm; dicot and monocotGymnospermae (naked seeds)Angiospermae (enclosed seeds)Cone; seeds exposedFruit (ovary) encloses seedDicot: tap root, reticulate veins, 2 cotyledonsMonocot: adventitious roots, parallel veins, 1 cotyledonDicot leafMonocot leaf

In the figure : Top: gymnosperm cone and angiosperm fruit; below: main differences of dicot and monocot.

Rule 1 : Gymnospermae — About 70 genera, 1000 species (India 16 genera, 53 species). Sporophyte; tap roots; Cycas coralloid roots with blue-green algae, Pinus roots with mycorrhizae. Dimorphic leaves: green foliage and brown scale leaves. Tracheids and sieve cells; cambium gives secondary growth. E.g. Cycas, Pinus, Ginkgo.

  • Easy : Ginkgo biloba = living fossil.
  • Medium : Tallest gymnosperm: Sequoia sempervirens (about 366 ft); smallest: Zamia pygmaea (about 25 cm).
  • Exam-type (CET) : Cycas coralloid roots live with? Blue-green algae (cyanobacteria).

Rule 2 : Angiosperms: dicot and monocot — Sporophyte dominant; gametophyte small and hidden. Stamens (microsporophylls) and carpels (megasporophylls) + calyx, corolla = flower. Dicot: 2 cotyledons, tap root, reticulate veins, 4–5-merous flowers, open bundles, cambium → secondary growth (sunflower, China rose). Monocot: 1 cotyledon, adventitious roots, parallel veins, trimerous flowers, closed bundles, no secondary growth (maize, jowar).

  • Easy : Grass leaf with parallel veins = monocot.
  • Medium : Why doesn't maize girth increase? No cambium.
  • Exam-type (CET) : Smallest angiosperm: Wolffia (1 mm); Eucalyptus over 100 m.
Remember

Gymnosperm = naked seed; angiosperm = seed in fruit. Monocot = 1 cotyledon; dicot = 2.

Common mistake and CET trap

‘Gymnosperms bear fruits’ is wrong. Trap: the angiosperm hallmark is double fertilisation; vessels in wood is also an angiosperm feature.

Shortcut

Memory clue : "Dicot = Duo cotyledons + Deep tap root; Monocot = Mop-like fibrous roots".

Spot the difference

PointDicotMonocot
Cotyledon21
RootTapAdventitious
Leaf venationReticulateParallel
Secondary growthPresentAbsent

Practice questions

Easy
  1. 1What does gymnos mean?
  2. 2An example of a gymnosperm.
  3. 3Where are seeds in angiosperms?
Medium
  1. 4Tallest gymnosperm?
  2. 5Which is a ‘living fossil’?
  3. 6Three differences between dicot and monocot.
Challenging
  1. 7Symbiosis in roots of Cycas and Pinus?
  2. 8Why do dicots show secondary growth but monocots do not?
Show answers (try them yourself first)
  1. 1Naked.
  2. 2Cycas / Pinus.
  3. 3Inside the fruit (ovary).
  4. 4Sequoia sempervirens.
  5. 5Ginkgo biloba.
  6. 6Cotyledons 2/1; root tap/adventitious; veins reticulate/parallel.
  7. 7Cycas: blue-green algae; Pinus: mycorrhizae.
  8. 8Dicots have cambium between xylem and phloem; monocots do not.

Alternation of generations and life-cycle patterns

From daily life

Grandparents, parents, us – generations change; in plants two different kinds of generation (n and 2n) alternate.

Simple definition

Alternation of generations: the diploid (2n) sporophyte forms haploid (n) spores by meiosis → they grow into gametophytes → gametes fuse → 2n zygote → sporophyte.

Three types of life cycleHaplonticDiplonticHaplo-diplonticn organism(dominant)Zygote (2n)only 2n cellfertilisationmeiosis → n sporese.g. some algae, fungi2n organism(dominant)Gametes (n)single cells onlymeiosisfertilisation → zygote (2n)e.g. animalsSporophyte 2nmulticellularGametophyte nmulticellularmeiosisgametesmitosis in both phasese.g. land plants,many algaeBryophyta: gametophyte dominant | Pteridophyta: sporophyte dominant

In the figure : Three life-cycle types: haplontic, diplontic and haplo-diplontic; n = haploid, 2n = diploid.

Rule 1 : Alternation of generations — Sporophyte (2n) → meiosis → spores (n) → mitosis → gametophyte (n) → gametes (n) → fertilisation → zygote (2n) → mitosis → sporophyte. Distinct alternation in bryophytes and pteridophytes; in gymnosperms and angiosperms the gametophyte is reduced and inside the sporophyte.

  • Easy : Spores are formed by which division? Meiosis.
  • Medium : Dominant: gametophyte in Bryophyta; sporophyte in Pteridophyta.
  • Exam-type (CET) : Gametes (n) form by mitosis in the gametophyte.

Rule 2 : Three life-cycle types — Haplontic: only the zygote is 2n and it undergoes meiosis; e.g. some algae, fungi. Diplontic: dominant 2n organism, gametes by meiosis; e.g. animals. Haplo-diplontic: both multicellular n and 2n phases, mitosis in both; e.g. land plants, many algae.

  • Easy : Only zygote 2n = haplontic.
  • Medium : Human life cycle = diplontic.
  • Exam-type (CET) : A fern's life cycle = haplo-diplontic.
Remember

2n = sporophyte; n = gametophyte; meiosis gives spores; fertilisation gives zygote.

Common mistake and CET trap

‘Gametes by meiosis’ is right for animals (diplontic); in plants gametes form by mitosis in the gametophyte. Trap: assuming sporophyte is dominant in all plants – wrong (Bryophyta).

Shortcut

Memory clue : "Haplo = Half (n) body; Diplo = Double (2n) body; both = Haplo-diplo".

Spot the difference

TypeDominant phaseOnly 2n / both?Example
Haplonticn organismZygote only 2nSome algae, fungi
Diplontic2n organismOnly gametes nAnimals
Haplo-diplonticBothBoth multicellularBryo/Pterido

Practice questions

Easy
  1. 1Chromosome number in sporophyte and gametophyte?
  2. 2Which division forms spores?
  3. 3Dominant generation in bryophytes?
Medium
  1. 4Which is the only 2n cell in a haplontic cycle?
  2. 5An example of diplontic.
  3. 6What is the gametophyte like in angiosperms?
Challenging
  1. 7Dominant generation of pteridophytes and its feature.
  2. 8Distinguish the three life cycles.
Show answers (try them yourself first)
  1. 1Sporophyte = 2n; gametophyte = n.
  2. 2Meiosis.
  3. 3Gametophyte.
  4. 4Zygote.
  5. 5Animals (human).
  6. 6Highly reduced, haploid, concealed in the sporophyte.
  7. 7Sporophyte; independent, vascular, with root, stem, leaves.
  8. 8Haplontic: organism n; diplontic: organism 2n; haplo-diplontic: both n and 2n multicellular phases.

Quick revision of the whole lesson

ConceptKey fact
ClassificationCryptogamae (Thallo-, Bryo-, Pteridophyta) / Phanerogamae (Gymno-, Angiospermae)
Green algaeChl a,b; starch; cellulose
Brown algaeChl a,c + fucoxanthin; mannitol; holdfast-stipe-frond
Red algaeChl a,d + phycoerythrin; Floridean starch; agar-agar
BryophytaGametophyte dominant; rhizoids; Funaria
PteridophytaSporophyte dominant; vascular; no secondary growth
Gymno / AngioNaked seed / seed in fruit; dicot 2, monocot 1 cotyledon
Life cyclesHaplontic, diplontic, haplo-diplontic

🎯 Most important points for the exam

  • Cryptogamae and phanerogamae and their subgroups.
  • Comparison of the three algal classes (pigments, reserve food, wall).
  • Bryophyta vs Pteridophyta: dominant phase, vascular tissue.
  • Gymnosperm vs angiosperm, and dicot vs monocot.
  • Alternation of generations and the three life cycles.
  • Numbers: Bryophyta 960/25,000; Pteridophyta 400/11,000; gymnosperms 70/1000.
Study mantra

Understand the concept → draw the figure → memorise the key points → solve questions yourself.