Plant Kingdom | Biology for Class 9 PDF Download

Characteristics : Plantae includes multicellular, eukaryote organisms with cellulosic with cell wall.

A mature plant cell commonly possess a single large central vacuole.

Plastids are found in all plants. Some plastids posses photosynthesis pigment. They are called chloroplasts.

Plants are autotrophic in nature because they are able to perform photosynthesis with the help of chlorophyll present in chloroplasts.

Reserve food is starch.

 Bases of Classification

On the basis of differentiation of plant body.

On the basis of conducting tissue.

On the basis of ability to bear seeds and seed are enclosed within fruits.

Following plant groups are included in kingdom-Plantae

1. Thallophyta

Main plant body is gametophyte.

Plant body is not differentiated into root, stem and leaves, called thallus.

These are found in marine, fresh water and moist land.

They have not mechanical and conducting tissue.

Asexual reproduction generally take place by spores.

Sex organs are simple single-celled, (the male sex organs are called as antheridia and female sex organ called oogonia) and their is no embryo formation after fertilization. 

Examples : 

Green algae - Spirogyra, Ulothrix, Cladophora, Chara, Ulva, Chlorella

Brown algae - Laminaria, Fucus, Sargassum.

Red Algae - Polysiphonia

2. Bryophyta

Bryophytes are also known as amphibians of plant kingdom.

These are the simplest and the most primitive land plant.

They have flat plant body which differentiate in to stem and leaf like structure.

Main plant body is gametophyte which attach to substratum by means of rhizoids.

Sex organs are multicellular and jacketed. Male sex organs are called antheridia while female sex organs are called archegonia.

Examples :
Liver wort - Riccia and Marchantia
Horn wort - Anthoceros
Moss - Funaria

3. Pteridophyta -

Main plant body is sporophyte which is differentiated into root, stem and leaves.

Vascular tissues, xylem and phloem, appear for the first time in pteridophyta.

They produces spores inside sporangia.

Gametophyte is a small but independent stage in life cycle.

Sex Organs are multicellular and jecketed like those of bryophytes male antheridia, female archegonia.

Male gametes need water for fertilization.

Seeds are absent.

Examples :

Club moss - Selaginella, Lycopodium
Horse tails - Equisetum
 |Ferns - Marsilea, Azolla, Adiantum,
Dryopteris, Pteris and Pteridium. 

Spermatophyta (Gk. sperma seed, phyton plant)

Characteristics : Main plant body is a sporophyte which is differentiated into stem, leaves and roots.
Vascular tissues are well-developed throughout the plant body.
Sporangia occur over modified leaves called sporophylls. Sporophylls are aggregated to form cones or flowers.
Male and female gametophytes are distinct. They are small and dependent on the sporophyte for their nutrition.
Male gametophytes or pollen grains reach near the female sex organs through an external agency of wind, water or animals. The process is called pollination. Fertilization occurs with the help of a pollen tube. An external water is not required.
After fertilization plants produce seeds which contains embryo along with stored food. On germination each seed forms a new plant.
Spermatophyta or phanerogams are classified into two groups (Gymnosperm, Angiosperm) on the basis of naked or enclosed seeds. 

4. Gymnosperm : 
Gymno- naked and sperm - seeds.
 Plants are evergreen, woody and perennial. They are trees and shrubs.
 Sporophylls are aggregated to form cones. There are separate male and female cones.
They bear naked seed. The seeds are not enclosed inside fruits. Instead they lie exposed over the megasporophylls.
Xylem lack vessels and phloem lack companion cells in Gymnosperm.

Examples :

Cycadae - Cycas
 Coniferae - Pinus (Pines), Cedrus (deodar),Ginkgo.

5. Angiosperm -
Angio- covered and sperm - seed.
Characteristics : Plants are deciduous or evergreen, annual
biennial or perennial herbs, shrubs or trees.
These are called flowering plant. Sporophylls are aggregated to form flowers. Flowers may be unisexual or bisexual.
Pollination occurs by wind, water and animals.
The plants of this group produce seeds inside an organ called ovary, which is modified in to fruit.
Endosperm is a new food storing structure which is generally triploid and is formed by fusion of three nuclei (triple fusion).
Embryo is present in the seed and bear leafy or fleshy structures called cotyledons (seed leaves)
Cotyledons represent a bit of pre-designed plant in the seed. 

In angiosperms, a seed may have one or two cotyledons. On the basis of cotyledon number, angiosperms have been divided into two classes, dicotyledoneae and monocotyledoneae.
Class Dicotyledoneae :

It is a class of angiosperms in which seeds possess tow cotyledons. The plants of this class are commonly called dicots or dicotyledonous plants. Some other characters are reticulate venation, tap root system, pentamerous or tetramerous flowers. eg. Gram, Pea, Mustard, Ipomoea.
Class Monocotyledoneae :

The members of class monocotyledoneae of angiosperms are characterised by the occurrence of a single cotyledon in their seeds. They are commonly called monocots or monocotyledonous plants. Other characters of monocots are parallel venation, fibrous root system, trimerous flowers. eg. Lily, Coconut, Wheat, Maize, Grass, Bamboo, Paphiopedilum.