CBSE Class 9 Science - Diversity in Living Organisms (Important Differences)

Diversity in Living Organisms

Evolutionary Tree
credits: wikipedia

Important Differences

Five classes of vertebrates are Pisces, Amphibia, Reptilia, Aves and Mammalia

	Pisces	Amphibia	Reptilia	Aves	Mammalia
Habitat	Aquatic	Both land and water	Some terrestrial, others aquatic	Terrestrial (aerial)	Usually terrestrial, few aquatic.
Skin	Covered with scales/plates	Smooth skin with mucus glands and lacking scales	Waterproof skin with scales	Mostly covered with feathers	Covered with hair and contains sweat and oil glands.
Body Temperature Control	Cold blooded	Cold blooded	Cold blooded	Warm blooded	Warm blooded
No. of heart chambers	2	3	3 (except crocodiles)	4	4
Respiration	Gills	Gills, lungs or skin	Lungs	Lungs	Lungs
Mode of Reproduction	Oviparous (egg laying)	Oviparous	Oviparous	Oviparous	Viviparous
Locomotion	Tail and fins	Limbs	Limbs	Wings	Limbs
Examples	Rohu, shark, sea-horse, sting ray	Frog, Toad salamander,	Crocodile, snake, turtle, lizard	Pigeon, ostrich, hen, duck	Human, whale, bat, lion

Five Kingdoms

Kingdom	Monera	Protista	Fungi	Plantae	Animalia
Cell Complexity	Prokaryotic	Eukaryotic	Eukaryotic	Eukaryotic	Eukaryotic
Body Design	Unicellular	Unicellular	Multicellular	Multicellular	Multicellular
Mode of Nutrition	Heterotroph or Autotroph	Heterotroph or Autotroph	Saprophytes	Autotroph	Heterotroph
Ecological Role	Decomposer	Consumer	Decomposer	Producer	Consumer
Other Characteristics	Locomotion by flagella	Pesuopads, intracellular movement	Cell wall made of chitin	Tissue Differentiation, seeds bearing etc.	Tissue Differentiation, Mostly mobile...
Examples	bacteria, blue-green algae	Amoeba, Paramecium,  Diatoms	Mushroom, Yeast	Ferns, green plants	Sponges, Fishes, Birds, Humans

Primitive vs Advanced Organisms

Primitive Organisms	Advanced Organisms
1. Simple body organisation.	1. Complex body organization.
2. Ancient body changes haven't changed much	2. Recent body design.
3. Considered at first ladder on evolutionary scale.	3. Considered at successive ladders on evolutionary scale.

Thallophytes vs Pteridophytes

Num.	Thallophytes	Pteridophytes
1.	Plant body is not well differentiated.	Plant body is differentiated into root, stems and leaves.
2.	No vascular system present for conduction of water and food substances.	Simpler vascular system present for conduction of water and substances.
3.	Mostly aquatic (algae)	Mostly land plants
4.	Spirogyra, Chara etc.	Ferns, Marsilea etc.

Pteridophytes vs Phanerograms

Num.	Pteridophytes	Phanerograms
1.	Have inconspicuous reproductive organs.	Well differentiated reproductive parts.
2.	Produce naked embryos called spores.	Produce seeds.
3.	Simple Vascular System	Highly differentiated vascular system
4.	Examples: Marsilea, Adiantum etc.	Examples: Pine, Cycas, Deodar, Sunflower, Maize etc.

Gymnosperms vs Angiosperms

Num.	Gymnosperms	Angiosperms
1.	Naked seed i.e. seeds not enclosed within fruit.	Seeds are enclosed with fruit walls (coltyledons).
2.	Flowers are represented as unisexual cones which produce spores.	Microspores are anthers while megaspores are ovules.
3.	Ovules not located in ovary	Ovules present inside ovary.
4.	Examples: Pines, Cycas, Deodar etc.	Examples: Sunflower, Maize, Wheat, Pea, bean etc.

Monocots vs Dicots

-	Monocots	Dicots
Cotyledons	One Cotyledon	Two Cotyledons
Veins in leaves	Usually Parallel	Generally netlike
Flower Parts	In general multiple of three	In fours or five
Arrangement of primary vascularbundles in stem	Scattered	In a ring

Poriferans vs Coelentrates

Num.	Poriferan Animals	Coelentrate Animals
1.	Cellular level organization.	Tissue level organization.
2.	Mostly marine and non-motile.	Aquatic either soliary life or colonial life.
3.	Examples: Spongilla, Euplectelia etc.	Examples: Hydra, sea anemones, corals etc.

Nematoda vs Annelids

Num.	Nematoda	Annelida
1.	Tissues but no real organs.	True organs packaged in body structure.
2.	Body Cavity is not true coelom (pseudocoelom)	True body Cavity
3.	Body is cylindrical	Body is segmented.
4.	e.g. Ascaris, Wucharia	e.g. Leeches, Earthworms, Nereis

Annelids vs Arthopods

Num.	Annelids	Arthropods
1.	True body cavity called coelem	Blood filled body cavity called haemocoel.
2.	Lateral appendages for locomotion.	Jointed legs for locomotion
3.	Closed circulatory system	Open circulatory System.
4.	Body is soft, there is no hard skeleton	Hard Exoskeleton made up of chitin
5.	Body is segmented both externally and internally (septa)	e.g. Body is externally divided but not internally by septa.
6.	e.g. Leech, earthworms etc.	e.g. Insects, spiders, prawns etc.