CHAPTER 2 GRADE 8TH

v Sub division of plants;

·       Difference b/w Flowering plants and Non-flowering plants

v Salient features of following non-flowering plants;

1)   Algae

·       Habitat

·       Life style

·       Structure

·       Mode of nutrition

·       Classification

·       Examples

·       Importance

v Fungi ;

·       Structure

Ø Hyphae

Ø Mycelium

·       Mode of nutrition

Ø Heterotrophs

Ø Parasites

Ø Saprotrophs

·       Examples

·       Importance

Ø Advantages

Ø Disadvantages

·       Mushrooms

v Mosses ;

·       Habitat

·       Life style

·       Root, stem & leaves

·       Vascular tissues

·       Examples

v Ferns ;-

·       Habitat

·       Roots, stem & leaves

·       Flowers, fruits, &seeds

·       Vascular tissues(xylem+phloem)

·       Examples

v Conifers;-

·       Habitat

·       Evergreen plants

·       Roots , stem ,

·       Leaves

·       Seed

·       Vascular tissues

·       Examples

v Salient features of Flowering plants;

·       Definition

·       Fruits & seeds

·       Classification

·       Types difference b/w MONOCOTS & DOCOTS

·       Importance

1.    Source of food

2.    Source of perfumes

3.    Source of wood

4.    Source of beauty

v Identification of plants with the help of key;-

·       Key

·       Plant key

o   Subdivision of plants;-

Plants are classified into following TWO major groups;-

1.    Flowering plants

2.    Non-flowering plants

·       Difference b/w flowering plants & non-flowering plants

Ø Flowering plants;-

These are vascular plants that produce flowers.

Examples;-

1.    Pea 

2.     Rose  

3.    Sarson

Ø Non-flowering plants;

They do not produce flowers.

Examples;

1.    Algae

2.    Fungi

3.    Mosses

4.    Ferns

5.    Conifers

o   Salient features of NON-FLOWERING plants;

·       Algae ;

They are the simplest group of plant kingdom.

Ø Habitat ;

They are found in fresh water & sea.

Ø Life style;

Algae either;

1.    Float in water

2.    Attached to stones

Ø Structure ;

1.    They are both UNICELLULAR & MULTICELLULAR.

2.    Some multicellular algae are in the form of filaments.

3.    Cells of algae contain NULEUS & other structures.

4.    They contain CHLOROPHYLL.

Ø Mode of nutrition;

Autotrophs;-

Due to presence of chlorophyll , they manufacture their own food through photosynthesis ,that is why they are called “AUTOTROPHS”.

Ø Classification;

On the basis of structural COLOUR & DIFEERENCES algae are classified as following;

1.    Green algae

2.    Brown algae

3.    Golden algae

4.    Red algae

Ø Examples;

1)   Chlamydomonas

2)   Spirogyra

Ø Importance;

They are source of OXYGEN & food for aquatic animals. In this way they have the basic position in FOOD CHAIN.

·       Fungi;

Ø Structure;

v Hyphae ;

Fungi are composed of numerous threads like structures called hyphae.

v Mycelium;

 Hyphae are in the form of groups called mycelium.

Ø Mode of nutrition;

1.    Heterotrophs; they lack chlorophyll, so they cannot manufacture their own food but get prepared food, hence are called heterotrophs. 

2.    Parasites; some are parasites & obtain their food from other living organisms.

3.    Saprotrophs; Majority of them are Saprotrophs i.e. they obtain their nutrition from decaying bodies of plants & animals.

Ø Examples ;

Rhizopus, mushrooms

Ø Importance;

v ADVANTAGES;

1.    Source of food; many fungi i.e. mushrooms are used as food, by man.

2.     Decomposition; fungi i.e. bacteria act as decomposers.

§  Decomposers;

“Organisms that decompose dead organic matter i.e. they convert complex compounds into simple ones are called decomposers.”

3.    Source of Antibiotics;

§  Penicillin is obtained from the FUNGUS  “penicillium”.

v DISADVANTAGES;

Fungi cause following diseases in plants, & human beings;

1.    In plants;

§  Rust

§  Smut

Diseases of WHEAT, MAIZE, RICE & SUGARCANE.

2.    In humans;

§  Athlete’s foot

§  Ringworm

·       Mushrooms;

~HABITAT;

During rainy season umbrella like mushrooms appear on dumps of debris and heaps of dung.

~There are various kinds of mushrooms.

~COMPOSITION;

They are rich in PROTEINS. Some  of them are fatal and poisonous & cause death.

·       Mosses ;

Ø Habitat;

They are found in cold, moist & shady places.

Ø Life style;

§  They live both in WATER & on LAND.

§  Early developmental stages are passes in water and rest of life as an adult stage live on land.

Ø Roots, stem, & leaves ; They lack root, stem & leaves BUT root, stem & leaf like structures are present.

Ø Vascular tissues;(xylem & phloem)

Vascular tissues are absent.

Ø Examples ;

§  Funeria

§  Polytricum

·       Ferns ;-

Ø Habitat ;-

They are adapted to live in cold, shady & humid places.

Ø Roots, stems, & leaves;

They have well developed roots, stems, & leaves.

Ø Flowers, fruits, & seeds;-

They do not produce flowers, fruits, & seeds.

Ø Vascular tissues;-

They are present.

1.    Xylem tissue for conduction of WATER.

2.    Phloem tissue for transpiration of food.

Ø Examples;-

§  Dryopteris

§  Adiantum

§  Pteris

·       Conifers:-

Ø Habitat ;-

They are found in colder & hilly areas i.e.

§  Muree

§  Kaghan

§  Swat

§  Gilgit

Ø Evergreen plants;-

They remain green throughout the year hence called evergreen plants.

Ø Roots, stem;-

They have prominent roots & stem.

Ø Leaves;-

The leaves are long, narrow, & needle like.

Ø Vascular tissues;-

Xylem & phloem are present in conifers.

Ø Examples;-

§  Deodar (cedar)

§  Pines (chir & chalgoza)

§  Thuja (moor pankh)

§  Saroo

§  Juniper (sanober)

·       Salient features of flowering plants;-

Ø Definition;-

“These are vascular plants & have flowers.

Ø Habitat ;-

These are found in plains.

Ø Fruits & seeds;-

They produce fruits & seeds.

Ø Classification ;-

They are classified into following groups;-

§  Herbs

§  Shrubs

§  Trees

Ø Types ;-

They are divided into following TWO groups on the basis of the NO. OF COTYLEDONS in the seed.

1.    Monocots or monocotyledons

2.    Dicots or dicotyledons

Ø Difference b/w MONOCOTS & DICOTS;-

MONOCOTS 1.Those plants which have one cotyledon in the seed. 2. Their leaves are long & have parallel veins. 3.examples;- Wheat, maize, rice, sugarcane, grass

DICOTS 1.Those plants which have two cotyledons in their seed. 2. Their leaves are usually broad, &have branched veins forming a network.  3.examples;- Pea, rose, sunflower, sarson, apple, mango, orange etc.

Ø Importance;-

1.    Source of food:

§  Cereals;-

Wheat, maize, rice, etc. are used as food.

§  Vegetables;-