Categories
Class 9 Science

Diversity in Living Organism:Animalia Class 9th Science Notes

ANIMALIA

Porifera

  • These are non-motile organisms with pores all over their body leading to canal system that helps in circulating water throughout the body to bring in food and oxygen.
  • These animals are covered with a hard outside layer or skeleton
  • They are commonly called sponges example- sycon, spongilla and euplectelia.

Coelenterata

  • The body of these animals have a cavity, and is made up of two layers of cells.
  • Some of these species live in colonies(corals) while others have solitary like span(hydra).

Platyhelminthes

  • The body of these animals are bilaterally symmetrical, and have three layers of cells and are thus called triploblastic.
  • The three layers of cells allow outside and inside body linings as well as some organs to be made.
  • There is no true coelom, in which well developed organs can be accommodated.
  • The body is flattened from top to bottom i.e dorsoventrally.
  • Examples are parasites like liver flukes or free-living animals like planarians.

Nematoda

  • The nematoda body is bilaterally symmetrical, triploblastic and cylindrical.
  • There are tissues but no organs and have a psuedo cavity
  • Examples of nematoda are worms causing elephantiasis i.e filarial worms and pinworms found in intestines.

Annelida

  • Annelida are bilaterally symmetrical, triploblastic and have a true body cavity, allowing organs to be packed in body structure.
  • Differentiation occurs in a segmental fashion with segments lined up one after the other from head to tail.
  • Earthworms and leeches are examples of annelida.

Arthropoda

  • This is the largest group of animals
  • They are bilaterally symmetrical, segmented, and have an open circulatory system and jointed legs.
  • The coelomic cavity is blood filled in arthropoda.
  • Examples of arthropoda are prawns, butterflies, scorpions and crabs.

Mollusca

  • They are bilaterally symmetrical, have reduced coelomic cavity and little segmentation
  • They have open circulatory system, kidney like organs for excretion and use foot for moving around
  • Example are snails and mussels.

Echinodermata

  • These are spiny skinned, free-living marine animals.
  • They are triploblastic, have a coelomic cavity and have peculiar water driven tube system that they use for moving around
  • They have hard calcium carbonate structures as skeleton.
  • Examples of echinodermata are starfish and sea urchins.

Protochordata

  • They are bilaterally symmetrical, triploblastic and have notochord.
  • Notochord is a long rod-like support structure that runs along the back of the animal separating the nervous tissue from the gut.
  • Protochords may not have a proper notochord present at all stages in their lives
  • Examples of protochords are balanoglossus, herdermania and amphioxus.
Balanoglossus
Balanoglossus

Vertebrata

  • These animals have a true vertebral column and internal skeleton, allowing a completely different distribution of muscle attachment points to be used for movement.
  • They are bilaterally symmetrical, triploblastic, coelomic, segmented, dorsal nerve chord, paired gill pouches.

(i) Pisces

  • These are fish.
  • Their skin is covered with scales, they obtain oxygen dissolved in water using gills, have a streamlined body and a muscular tail.
  • They are cold-blooded, have two chambered heart and lay eggs
  • Examples are tuna, rohu and angler fish.

(ii)Amphibia

  • They lack scales, have three-chambered heart and mucus glands in their skin .
  • They respire through gills or lungs and lay eggs.
  • Examples of amphibia are salamanders and hyla.

(iii)Reptilia

  • These animals are cold-blooded, have scales, lay eggs, have three chambered heart and respire through lungs
  • Crocodiles have four-chambered heart.
  • Turtles, lizard and chameleon are examples of reptiles.
Nile crocodile

(iv)Aves

  • They are warm-blooded, have four chambered heart, lay eggs and have an outside covering of feathers.
  • They have two forelimbs modified for flight and breathe through lungs
  • Examples are ostrich, crow, sparrow etc.

(v)Mammalia

  • Mammals are warm-blooded, have mammary glands for production of milk to nourish young ones.
  • Their skin have hair as well as sweat and oil glands
  • Platypus and echidna lay eggs.
  • Examples of mammals are human, whale, bat etc.

Diversity in Living Organisms NCERT Solutions

Diversity in Living Organisms:NCERT Notes Class 9th

Categories
Class 9 Science

Diversity in Living Organisms:NCERT Notes Class 9th

  • Classification is the Science of arranging organisms in series of groups and subgroups on the basis of their similarities and dissimilarities.
  • Aristotle classified organisms on the basis of their habitat means the place where they live, in water, in air and on land
  • We look for similarities among the organism which allows us to put them into different classes and then study them as a whole.
  • Characteristics are details of appearance or behaviour.
  • The characteristics that decide the broadest divisions among living organisms are independent of any other characteristic in their effects on the form and function of the organism
  • The characteristic in the next level would be independent on the previous one and would decide the variety in the next level.
  • Once a body design comes into existence, it will shape the effects of all subsequent design changes.
  • Characteristics that come into existence are likely to be more basic than characteristics that have come into existence later.
  • Some group of organisms have ancient body designs that have not changed very much and are referred to as primitive or lower organisms.
  • Some group of organisms have acquired their particular body design relatively recently and are referred to as advanced or lower organism.

HIERARCHY OF CLASSIFICATION

  • The kingdoms proposed by whittaker proposed has five kingdoms: Monera, protista, fungi, plantae and animalia.
  • Woese introduced modification by dividing monera into archaebacteria and eubacteria.
  • Classification is done by naming the sub-groups at various levels in the following scheme: kingdom, phylum, class, order, family, genus, species.
  • A species include all organisms that are similar enough to breed and perpetuate.

Further classification is done by naming the subgroups at Various levels as given:
Kingdom→Phyllum\Divison→Class→Order →Family→Genus→Species
•Kingdom Monera
•Kingdom Protista
•Kingdom Fungi
•Kingdom Plantae
•Kingdom Animalia

Monera

  • Organisms in monera kingdom do not have a defined nucleus, organelles or multicellular body design.
  • They may or may not have cell walls
  • The mode of nutrition in organisms of monera kingdom can be autotrophic as well as heterophic.
  • This group includes bacteria, blue-green algae or cyanobacteria, mycoplasma and anabaena.

 

 

Protista

  • Organisms of this group are unicellular, eukaryotic and some of them organisms use appendages, such as hair-like cilia or whip-like flagella for moving around.
  • Examples are unicellular algae, diatoms and protozoans

Fungi

  • Organisms in this group are heterotrophic, eukaryotic and use decaying organic material as food and are therefore called saprophytes.
  • Many of these organisms have the capacity to become multicellular organisms at a certain stages in their lives.
  • They have cell walls made of tough complex sugar called chitin.
  • Yeast, mushrooms, aspergillus, penicillium and agaricus.

  • Some fungal species live in symbiotic relationships, and these life-forms are called lichens.

Plantae

  • The organisms in this group are are multicellular, eukaryotes, autotrophs and use chlorophyll for photosynthesis
  • All plants are included in this group.

Animalia

  • These include all organisms which are multicellular eukaryotes, without cell walls, and are heterotrophs.

PLANTAE

Thallophyta

  • Plants in this group are predominantly aquatic and do not have well-differentiated body design fall in this group.
  • Plants in this are commonly are called algae.
  • Examples of thallophyta are spirogyra, ulothrix, cladophora and chara.

Bryophyta

  • Bryophytes are called the amphibians of the plants.
  • The plants in this group do not have special tissues for conduction of water and other substances from one part of the plant body to another.
  • Examples of bryophyta are moss and marchantia.
  • The plant body is commonly differentiated to form stem and leaf-like structures.

Moss Biodevirsity

Pteridophyta

  • The plant body is differentiated into roots, stem and leaves and has specialised tissue for the conduction of water and other substances from one part of the plant body to another.
  • Plants of pteridophyta are cryptogamae.
  • Cryptogamae are plants with hidden reproductive organs.
  • Phanerogams are plants with well differentiated reproductive tissues that ultimately make seeds.

Gymnosperms

  • The plants of this group bear naked seeds and are usually perennial, evergreen and woody
  • Pines such as deodar are example of gymnosperms

Deodar
Deodar

Angiosperms

  • The seeds of these plants develop inside an organ.
  • These are also called flowering plants.
  • Plant embryos in seeds have cotyledons i.e seed leaves.
  • Monocots are plants with seeds having one cotyledon.
  • Plants with seeds having two cotyledons are called dicots.

Appear the quiz on Biodiversity here

Read the second part of this lesson on Animal Kingdom notes for Class 9th science here

Categories
Class 9 Science

Animal Tissue Classification and Notes Class 9 NCERT

ANIMAL TISSUES

Epithelial tissue

  • The covering or protective tissue in animal body are epithelial tissue, covering most organs and cavities it forms a barrier to keep different body systems separate.
  • The skin, the lining of the mouth, the lining of blood vessels, lung alveoli and kidney tubules are made up of epithelial tissue.
  • Cells of epithelial tissue are tightly packed and form a continuous sheet having small amount of cementing material between them and almost no inter-cellular spaces.
  • All epithelium are separated from the underlying tissue by an extracellular fibrous basement membrane.

Epithelial tissue Classification

i) Squamous epithelial tissue 

  • Squamous epithelial tissue consists of a layer of thin flat cells.
  • It is present in the linings of blood vessels, lungs, mouth, oesophagus etc.
  • The skin has several layers of epithelial cells. This tissue is called Stratified squamous tissue.

ii) Columnar epithelial tissue :-

  • Columnar epithelial tissue consists of tall pillar like cells.
  • It is present in the walls of the intestine.
  • The columnar epithelial tissue in the respiratory tract has hair like projections called cilia.
  • This tissue is called Ciliated columnar epithelial tissue.

iii) Cuboidal epithelial tissue :-

  • Cuboidal epithelial tissue consists of cone shape cells having a basement membrane.
  • It forms the lining of kidney, tubules and ducts of salivary glands and provide mechanical support.

iv) Glandular epithelial tissue :-

  • Sometimes epithelial tissue folds inwards and forms a multicellular gland which secretes substances.
  • This tissue is called Glandular epithelial tissue.

NCERT Solutions Class 9 Science Tissues

Connective tissue

  • The cells of a connective tissue are loosely packed and embedded in inter cellular matrix, this matrix may be jelly like, fluid, dense or rigid.
  • Blood is a type of connective tissue.

i) Blood :-

  • Blood contains a fluid matrix called plasma which contains red blood cells (RBC), white blood cells (WBC) and platelets.
  • The blood transports gases, digested food, hormones, waste materials etc.

ii) Bone :-

  • Bone is a hard and strong tissue
  • It consists of cells which are embedded in a hard matrix containing calcium and phosphorus compounds.
  • Bone forms the framework of the body and supports the body and the main organs.

iii) Ligaments :-

  • Ligaments are flexible tissues which joins bones together and helps in movements.

Ligaments

iv) Tendons :-

  • Tendons are fibrous tissues which joins muscles to bones and helps in movements.

v) Areolar tissues :-

  • It fills the space between skin and muscles, inside the organs, around blood vessels etc.
  • It helps to repair the tissues.

vi) Adipose tissue :-

  • Adipose Tissue is found below the skin and between internal organs.
  • It contains fats and helps to store fats.

Muscular tissue

Muscular Tissue
Muscular Tissue
  • Muscular tissue contains elongated cells are called muscle fibres and is responsible for movement in our body.
  • Muscular tissue contains special proteins called contractile proteins which can contract and relax.
  • Muscles that move by our conscious will are called voluntary muscles for example muscles present in our limbs and are also called skeletal muscles .
  • Muscles which do not move under our will are called involuntary muscles.

i) Striated muscles :-

  • Striated muscles are voluntary muscles having light and dark striations.
  • The cells are long, cylindrical and are multinucleated.
  • They are also called skeletal muscles because they are attached to bones.
  • They help in voluntary movements of the body.

ii) Unstriated muscles ( Smooth muscles) :-

  • Unstriated muscles are involuntary muscles having no striations.
  • The cells are long and spindle shaped and are uninucleated.
  • They are present in alimentary canal, blood vessels, bronchi of lungs, iris of eye etc.
  • They help in involuntary movements.

iii) Cardiac muscles :-

  • Cardiac muscles  are involuntary muscles having faint striations.
  • The cells are long, cylindrical, branched and multinucleated.
  • They are present in the heart and helps in the contraction and relaxation of the heart.

Nervous Tissue

  • Nervous tissue is highly specialized for responding and transmitting stimulus very rapidly.
  • Nervous tissue have cells called neurons containing a cell body with a nucleus and cytoplasm
  • Each neuron has single long part called axon and many short branched part called dendrites.
  • The combination of functions of nerves and muscle tissue is fundamental to animals.

NCERT Solutions Class 9 Science Tissues

Click Here for Quiz on Tissue 

Read the First part of the lesson on Plant Tissue here 

Categories
Class 9 Science

Plant Tissues NCERT Notes for Class 9 Science

What is Tissue

  • Tissue is a group of cells that are similar in structure and/or work together to achieve a particular function.
  • Eg :- In human beings the cells of the muscular tissue contract and relax and help in movements.
  • In plants the cells of the vascular tissue conduct water and food from one part of the plant to the other

Differences between plant and animal tissue

  • Plants do not move from place to place. Most of the cells and tissues in plants provide mechanical support and strength.
  •  Since dead cells do not need maintenance and provide with mechanical support, thus the plant tissues are mainly composed of dead cells
  • The growth of plants takes place only in some regions. So plants have tissues called meristematic tissues which divide and help in growth and permanent tissues which do not divide
  • Animal tissues are composed of mainly living cells.
  • Animals grow uniformly thus there is no such demarcation of dividing and non-dividing regions in animals.
  •  Animals have organs having specialized functions. So the organs have specialized tissues

PLANT TISSUES

Meristematic tissue

  • The growth in plants is limited to specific regions thus the meristematic tissue is located at only these regions
  • The are three types of meristematic tissue apical, lateral and intercalary.
  • When meristematic cells produce new cells the two cells are similar, but as they grow they become differentiated as components of other tissues.
  • Apical meristem is present at the growing tips of stem and roots and increases the length of the stem and root.
  • Intercalary meristem is present at the base of the leaves or internodes on twigs
  • The girth of the stem or root increases due to lateral meristem.
  • Cells of meristematic tissue are very active hence have very dense cytoplasm, this cellulose walls, prominent nuclei and lack vacuoles.

Permanent tissue

  • The cells produced by meristematic tissue take a specific role and loose the ability to divide.
  • Differentiation is the process of taking up a permanent shape, size and function.

Simple permanent tissue

 

  • Parenchyma is a basic packing tissue, consisting of relatively unspecialised cells with thin cell walls.

    parenchyma
    Parenchyma
  • Parenchyma has live cells and are loosely packed.
  • It provides support to plants as well as store food.
  • It stores excretory products such as gums, raisins, tannins and crystals/
  • It may also contain chlorophyll and perform photosynthesis, in such situations it is called collenchyma.
  • In aquatic animals parenchyma contains large air cavities to help them float by giving buoyancy and is called aerenchyma.
  • The parenchyma of stems and roots stores nutrients and water.
  • Collenchyma is a permanent tissue responsible for flexibility in plants along with providing mechanical support and is present in leaf stalks below epidermis.
  • The cells of collenchyma are elongated, irregularly thickened at corners and have very less intercellular space.
  • Sclerenchyma is a permanent tissue which makes plant hard and stiff, and is made up of dead cells, that are long and narrow as the walls are thickened due to lignin.
  • Sclerenchyma is present at veins of leaves, hard covering of seeds and vascular bundles.
  • Coconut husk is made of sclerenchymatous tissue.
  • There are two types of sclerenchyma fibers and sclereids.
  • Sclerenchyma protects plants from the stress and strain of environmental factors like wind.
Epidermal cells
Epidermal cells
  • The outermost layer of cells is called epidermis and is usually made up of single layer of cells and the entire surface of the plant is covered by epidermis.
  • Epidermal cells on the aerial parts of the plant secrete a waxy, water resistant layer on outer surface to aid water loss, mechanical injury and invasion by parasitic fungi.
  • Due to the protective layer that epidermal cells play, they form a continuous layer without intercellular spaces in tissue, are relatively flat and their outer and side walls are thicker than inner wall
stomata
stomata
  • Stomata are pores present in epidermis of tissue enclosed by two kidney shaped cells called guard cells and are responsible for exchanging gases and transpiration.
  • In desert plants epidermal tissue secretes a waxy coating of cutin on its outer surface to prevent loss of water.
  • As plants grow older a strip of secondary meristem replaces the epidermal tissue of the stem and this forms the bark of the tree and cork.

Visit Here for Nitrogen Cycle Explained

cork
cork

Complex permanent tissue

  • Complex permanent tissues are made up of more than one type of cells coordinating to perform a common function
  • Xylem and phloem are a type of complex tissue.
  • They are both conducting tissues and constitute a vascular bundle, which is a feature of complex plants which made their survival possible in terrestrial environment.

Xylem :-

  • Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres.
  • The tracheids and vessels help to transport water and minerals from roots to all part of the plant.
  • Xylem parenchyma stores food and fibres help in support.
  • Xylem cells have thick walls and are dead.

Phloem :-

  • Phloem Consists of sieve tubes, companion cells, phloem parenchyma and phloem fibres.
  • The sieve tubes and companion cells transports food from leaves to all parts of the plant.
  • Phloem parenchyma stores food and fibres help in support
  • Unlike xylem in phloem, materials can move in both directions.

Appear a quiz on what you have read 

Visit here for the Second Part on Animal Tissue Here 

NCERT Solutions on Tissue