Tuesday, 18 March 2014

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;-








No comments:

Post a Comment