Ch 02: Plant Kingdom | Exam Fusion Prep

Eukaryotic

Cell Type

Multicellular

Organisation

Sessile

Movement

Autotrophs

Nutrition Mode

🌱 Key Features of Plants

Eukaryotic, Multicellular and Sessile living beings
Photosynthetic Autotrophs
Cellulosic cell wall and Plastids are present

⚡ Quick Recall

Three distinctive features of plants are: Sessile (fixed/no movement) + Cellulosic cell wall + Plastids. All three are absent in animals.

🔢 Subkingdom — Big Picture

1. Cryptogams (Seeds Absent)

Inconspicuous (hidden) reproductive organs
Reproduction by spores
Thallophyta — undifferentiated body (Algae)
Bryophyta — no vascular tissue, root-like structures
Pteridophyta — vascular tissues present, true root/stem/leaves

2. Phanerogams (Seeds Present)

External reproductive organs (cone or flower)
Gymnosperm — Naked seeds
Angiosperm — Seeds covered by ovary
Monocot & Dicot (based on cotyledon)

⚠ Exam Trap

Cryptogam = seeds absent | Phanerogam = seeds present. Gymnosperm = naked seeds (no ovary). Angiosperm = seeds covered by ovary/fruit.

🔀 Plant Kingdom — Classification Overview

Group	Seeds	Vascular Tissue	True Root/Stem/Leaf	Dominant Gen.	Examples
Thallophyta (Algae)	Absent	Absent	Absent	Gametophyte	Spirogyra, Chlamydomonas, Sargassum
Bryophyta	Absent	Absent	Absent (root-like rhizoids)	Gametophyte	Marchantia, Funaria, Sphagnum
Pteridophyta	Absent	Present	Present	Sporophyte	Ferns, Selaginella, Equisetum, Pteris
Gymnosperm	Present (Naked)	Present	Present	Sporophyte	Cycas, Pinus, Ginkgo, Gnetum
Angiosperm	Present (Covered)	Present	Present	Sporophyte	Wheat, Rose, Mango, Corn

⚡ Quick Recall

Thallophyta + Bryophyta = Gametophyte dominant. Pteridophyta + Gymnosperm + Angiosperm = Sporophyte dominant.

🌊 Thallophyta / Algae — Key Features

Thallus-like body; thick cell wall in green algae (Outer: Pectin + Inner: Cellulose)
Mostly aquatic
Vascular and mechanical tissues are absent
Gametophyte generation is dominant
In most green algae: starch bodies called Pyrenoids present in chloroplast
Marine algae like Laminaria attach to rocks via Holdfast

💰 Economic Importance of Algae

Product / Role	Source / Detail
CO₂ Fixation	Major contributor in aquatic systems
Producer in aquatic food chain	Primary producers
Food	Porphyra, Sargassum
Algin	From Brown algae
Carrageenan	From Red algae
Agar	Gelidium and Gracilaria
Protein / Space food	Chlorella and Spirulina

⚠ Exam Trap

Algin → Brown algae | Carrageenan → Red algae | Agar → Gelidium & Gracilaria (Red). Both algin and carrageenan are hydrocolloids.

📊 Types of Algae — Comparison

Feature	Chlorophyceae (Green)	Phaeophyceae (Brown)	Rhodophyceae (Red)
Common Name	Green Algae	Brown Algae (usually marine)	Red Algae (usually marine)
Pigments	Chlorophyll-a, b	Chlorophyll-a, c; Fucoxanthin	Chlorophyll-a, d; Phycoerythrin
Stored Food	Starch	Mannitol, Laminarin	Floridean Starch
Examples	Chlamydomonas, Volvox, Spirogyra (filamentous freshwater)	Fucus, Ectocarpus, Sargassum, Laminaria	Polysiphonia, Porphyra, Gracilaria

⚡ Quick Recall

The distinctive pigment of brown algae is Fucoxanthin. The distinctive pigment of red algae is Phycoerythrin. Spirogyra = freshwater filamentous green algae.

🍃 Bryophyta — Key Features

Amphibians

of Plant Kingdom

Oogamous

Sexual Reproduction Type

Gametophyte

Dominant Generation

Present in wet and moist habitats
True root, stem and leaves are absent
Rhizoids present (root-like structures)
Vascular tissues absent
Gametophytic generation dominant; sporophytic generation dependent on gametophyte
Known as "Amphibians of Plant Kingdom"
Sexual Reproduction is Oogamous type

⚠ Exam Trap

Bryophyta are known as the “Amphibians of the Plant Kingdom,” a fact frequently tested directly in MCQs. Vascular tissue is absent in Bryophyta but present in Pteridophyta.

📋 Types of Bryophyta

1. Liverworts

Body: Thalloid
Examples: Marchantia, Riccia
Marchantia: Archegoniophore, Gemma cup, Thallus, Rhizoid

2. Mosses / Hornworts

Body: Leafy
Spores produced in capsule; Protonema formed from spores
Examples: Funaria, Polytrichum, Sphagnum
Funaria = Cord Moss
Sphagnum = Bog Moss

⚡ Quick Recall

Marchantia → Liverwort | Funaria/Sphagnum → Mosses. Sphagnum = Bog moss, also called peat moss; it was used as fuel.

🌿 Pteridophyta — Key Features

Botanical Snakes

of Plant Kingdom (Completely Terrestrial)

Sporophyte

Dominant Generation

Present in damp and shady places
Body differentiated in Root, Stem and Leaves (true organs present)
Vascular tissues (Xylem and Phloem) are present
Water is necessary for sexual reproduction
Main plant body is sporophytic
Male gametes formed in Antheridium
Examples: Ferns — Selaginella, Pteris, Equisetum, Psilotum

⚠ Exam Trap

Equisetum is the only living representative of Sphenopsida. This fact is frequently tested directly in MCQs.

⚡ Quick Recall

Pteridophyta were the first land plants with vascular tissue. Vascular tissue is absent in Bryophyta but appears in Pteridophyta. Seeds are still absent.

🌲 Gymnosperm

Naked seeded plants (Gymno = naked, Sperma = seed)
Ovary, fruit and true flower — Absent
Main plant body — Sporophytic
Root, stem and needle-like leaves present
Reproductive organ: Unisexual cone
Endosperm is Haploid
Companion cells of phloem and xylem vessels — Absent
Evergreen and woody trees/shrubs
Examples: Cycas, Pinus, Ginkgo, Gnetum

⚠ Exam Trap

In gymnosperms, fruit is absent because the ovary is absent, and the endosperm is haploid. In angiosperms, the endosperm is triploid (3n).

🌸 Angiosperm

Plants with well-developed flowers and covered seeds
Fruit (Ovary) present — contains seeds (ovules)
Double Fertilisation present
Triple Fusion present
Triploid (3n) Endosperm present
Further divided into: Monocot & Dicot

⚡ Quick Recall

Distinctive features of angiosperms are: Double fertilisation + Triple fusion + Triploid endosperm. All three occur only in angiosperms.

🔍 Gymnosperm vs Angiosperm — Quick Compare

Feature	Gymnosperm	Angiosperm
Seeds	Naked (no ovary)	Covered (inside ovary/fruit)
Flower	Absent	Present
Fruit	Absent	Present
Endosperm	Haploid (n)	Triploid (3n)
Double Fertilisation	Absent	Present
Companion Cells	Absent	Present
Leaves	Needle-like	Broad
Examples	Cycas, Pinus, Ginkgo	Wheat, Rose, Mango

🌾 Monocot vs Dicot — Complete Comparison

Feature	Monocot Plant	Dicot Plant
Cotyledon	One (1)	Two (2)
Root	Adventitious / Fibrous roots	Tap roots
Stem (Vascular bundles)	Scattered	Arranged in ring
Leaves	Isobilateral — Parallel venation	Dorsiventral — Reticulate (network) venation
Flower (Floral whorls)	Multiples of 3	Multiples of 4 or 5
Examples	Corn, Wheat, Pearl millet (Bajra)	Rose, Chickpea (Chana), Tomato

⚠ Exam Trap

In monocots, floral whorls occur in multiples of 3 (3, 6, 9...). In dicots, they occur in multiples of 4 or 5. Venation: Monocot = Parallel | Dicot = Reticulate (network). This distinction is frequently tested.

⚡ Quick Recall — Memory Trick

Monocot = 1 cotyledon, 3× flowers, Parallel venation, Fibrous roots | Dicot = 2 cotyledon, 4/5× flowers, Reticulate venation, Tap root

Wheat/Corn/Rice = Monocot (important crops!) | Rose/Tomato/Mustard = Dicot

🌾 Monocot Examples

Corn (Maize)
Wheat
Pearl Millet (Bajra)
Rice, Bamboo, Sugarcane
Banana, Onion

🌹 Dicot Examples

Rose
Chickpea (Chana)
Tomato
Mustard, Pea, Bean
Mango, Apple, Potato

🌿 Chapter 02 — Plant Kingdom