Wednesday 30 December 2015

ANNELIDA PHYLUM

*habitat-they live in fresh water, marine water or moist soil. some are free living some are parasite.
*segmentation-metameric segmentation is found. the ring like grooves  are called annuli,each segment is called metameres. the first segment is called peristomium, and d the last segment is called prostomium.
*symmetry-bilateral
*germ layers- triploblastic
*level of organization-organ system level
*setae and parapodia-setae are often  present in annelida, in  Nereis  parapodia is found. leaches are its exception.
*body wall- body is covered by cuticle.
*body cavity-schizocoelic coelom
*skeleton- hydrostatic skeleton
*digestive tract is complete.
*respiratory organ-cutaneous respiration , branchial respiration(respiration through gills)
*blood vascular system- it is usually closed type.presence of erythrocruorin.
*excretory system- it consists of nephridia.
*nervous system-it consist of nerve ring, nerve cord , ganglia
*receptors- tactile receptor,gustatoreceptors are usually found.
*sexes- both unisexual and bisexual.
*development- it is mostly direct.
*annelida is classified on the basis of presence and absence of setae-
polychaeta-they have well developed parapodia with numerous setae. e.g.- Nereis
oligochaeta-the body has simple and few setae. e.g.-Pheretima
hirudinea-there are no parapodia or setae. e.g.- leaches

*e.g. of annelida-Nereis,Aphrodite, Sabella, Arenicola,Pheretima, Lumbricus, Tubifex, Hirudinaria etc


PHERETIMA




LEECH





NEREIS

ASCHELMINTHES / NEMATHELMINTHES PHYLUM (NEMATODA)

*commonly called as round worm
*habitat-most of them are parasite on plant and animals. some are free living in fresh water, marine water or soil.
*body form- body of round worm is cylindrical and elongated. it is called round worm because cross section of this is round. their is no segmentation found.
*symmetry-they show bilateral symmetry.
*germ layers-triploblastic
*level of organization- organ system level
*body wall-it consists of cutical, syncytial epidermis and muscle layer.
*body cavity- pseuducoelomates
*digestive tract is complete
*skeletal, respiratory and circulatory system are absent.
*excretory system- it consists of gland cell or intracellular canal or both.
*nervous system-it consists of circumpharyngeal ring
*sexes-they are unisexual generally. fertilization is internal.
*development-it may be direct or indirect.
*some common name and their scientific name of aschelminthes-
Ascaris- round worm
Ancylostoma-hook worm
Wuchereria- filaria worm
Dracunculus-guinea worm















PLATYHELMINTHES PHYLUM

*they have dorso-ventrally flat body, hence they are called flat worms.
*habitat-they are mostly parasite and few are free-living
*body form-flat body without segmentation
*symmetry-bilateral symmetry.
*germ layer-triploblastic
*level of organization-organ system level of oraganization
*body wall-it is soft and ciliated
*body cavity-they do not  contain coelom,thus they are acoelomate. parenchyma tissue are present in cavity which help intransporting food material
*digestive tract-incomplete digestive tract.
*skeletal,respiratory and circulatory systems are absent
*excretory system- by flame cell
*nervous system-it is ladder like structure and consists of brain and two main longitudinal nerve
*reproductive system-these animals are generally hermaphrodite. the fertilization is always internal. asexual repriduction is by transverse binary fission.
*development- indirect.
*regeneration-well marked in Planaria.
*classification on the basis of mode of life-
*turbellaria-Dugesia
*termatoda-Fasciola
*cestoda-Taenia
*scientific name with their common names of some platyhelminthes-
Dugesia- planaria
Schistosoma- the blood fluke
Fasciola- the liver fluke
Taenia solium-tape worm
LIVER FLUKE



PLANARIA




TAPE WORM

CTENOPHORA PHYLUM- THE COMB JELLIES

*habitat-all are marine
*habits-they are carnivorous and feed on plankton
*body form-they may be rounder, conical, oval or flattened
*symmetry-biradial i.e.-radial+bilateral
*germ layers-diploblastic
*level of organization-tissue level
*appendages-tentacles may or may not be present
*body wall-outer epidermis,inner-gastrodermis and middle-mesogloea. mesoglea is different from coelentrates.
*special adhesive cells are present on epidermis of tentacles called colloblast.
*locomotion-by cilia
*body cavity-they are acoelomates
*digestive tract-it consists of mouth, pharynax or stomodaeum, stomach or infundibulum;anal canal and two anal pores. digestive system is complete. both intra and extracellular digestion occurs.
*skeletal,circulatory, respiratory and excretory system are absent.
*reproduction-by sexual mean
*ctenophora is classified into two classes-
tentaculata-they have tentacles. e.g.-Ctenoplana
nuda-they do not have tentacles. e.g.-Beroe

BEROE



COELENTERATA PHYLUM (CNIDARIA)

*habitat-all are aquatic and mostly marine.they are solitary or colonial.
*body form- many coelenterates like obelia is a trimorphic colony having three kind of individuals.
    polyps:-nutritive zooids
    blastostyles:-budding zooids.
    medusae:-sexualzooids.
*symmetry- radial
*germ layer-diploblastic
*level of organization-tissue level
*body wall- it consists of two layers of cell epidermis and gastrodermis, and the gelatinous layer                              between them is mesoglea.the epidermis consists of many different cell:-
                     epitheliomuscular cell
                     cnidoblast
                     interstitial cell
                     nerve cell
                     sensory cell
*digestive tract-incomplete tract , the body cavity has only one opening
*digestion- both intra and extra cellular digestion
*respiration and excretion- diffusion by body surface.
*nervous system-premitive form of nervous system is found.
*skeleton-in some coelentrates calcareous exoskeleton or endoskeleton is found.
*reproduction-both sexual and asexual reproduction is found.
*development-the cleavage is holoblastic, and both direct and indirect development is found.
*cnidaria are divided into three classes on the basis of dominance of polypoid and medusoid phase.
   1. hydrozoa- polyp and medusae are found
   2. schyphozoa-they are represanted by medusae
   3. anthrozoa- they are represented by polyp form.

*some scientific and common names of coelentrates-
Obelia- sea fur
Physalia-portuguese man of war
Porpita Velella-by the wind sailor
Aurelia- jelly fish
Gorgonia-sea fan
Metridium-sea anemone
Alcyonium-dead man's finger
Tubipora- organ pipecoral
Astraea-star coral
Pennatula-sea pen















Tuesday 29 December 2015

PORIFERA PHYLUM


SPONGES

*habitat- all sponges are aquatic, mostly marine, rarely fresh water, solitary or colonial. alla re sessile, attached to the substratum.
*body form- they are vase like, cylinderical, cup shaped, spherical, or disc like. their body is porous,the inhalent pore is called ostia and the exhalent pore is called osculum.
*symmetry.-they are asymmetrical.
*germ layer-diploblastic animal.
                     sponges are first multicellular diploblastic animal.
*level of organisation-cellular level
*body wall-consist of three layers:-
                     choanoderm (=gastrel layer)
                     mesohyl layer (middle layer)
                     pinacodern(outer layer)
*canal system-three types of canal system are-
                       asconoid canal system- simplest canal system. e.g.-leucosolenia
                       syconoid canal system- it is more complex than asconoid system.e.g.- sycon
                       leuconoid canal system- it is the most complex canal system.e.g.- spongilla
*digestion- interacellular digestion
*respiration- diffusion of gases through plasma membrane.
*excretion-removal of waste is also by diffusion with the help of plasma membrane.
*reproduction- both sexual and asexual(budding and gemmule) reproduction occur.
*development- development is indirect and includes a free swimming larva, the amphiblastula or                                  parenchymula.

*sponges are also called by their common names, some are mentioned here-
Sycon- scypha
Euplectella-the venus' flower basket
Spongia-bath sponge
Spongilla-fresh water sponge
Hyalonema-the glass rope sponge
Leucosolenia- orange pipe sponge



SPONGILLA

NOTOCHORD

notochord is mesodermally derived rod-liked structure formed on the dorsal side during embryonic development in some animals. animals with notochord are called chordates and animals without notochord is called non-chordates. e.g.-porifera to echinodermata.

SEGMENTATION



* in some animal the body part are divided into many similar segments, as like in earthworm . it has metameric segmentation.

COELOM (BODY CAVITY)

* the body cavity , which is lined by mesoderm is called coelom.
*presence or absence of coelom is very important in classification..

*coelomates- animal posses coelom is called coelomates.e.g- annelida, mollusca, arthropoda, echinodermata, hemichordata and chordates
.
*pseudocoelomates- the body cavity is not lined by mesodern and it is found in scattered form, such body cavity is called pseudocoelom and the animal possessing them is called pseuducoelomates. e.g.-aschelminthes

*acoelomates-the animal in which the body cavity is absent is called acoelomates. e.g.- platyhelminthes.

DIPLOBLASTIC AND TRIPLOBLASTIC

*diploblastic- animals in which the cells are arranged in two embryonic layers, an external ectoderm and internal endoderm are called diploblastic.e.g.-coelentreta.

*an undifferentiated layer mesoglea is present in between ectoderm and endoderm.

*triploblastic-those animal in which the developing embryo has a third germinal layer, mesoderm is called triploblastic.e.g.- platyhelminthes to chordates



SYMMETRY OF BODY OF ORGANISM

asymmetrical- sponges are asymmetrical.i.e. any plane that passes through the center does not divide them into equal halves.

radial symmetry- the plane passing through the central axis of the body divides the organism into two identical halves, it is called radial symmetry.coelentrata,ctenophora and echinodermata have this kind of body plan.

bilateral symmetry-the body can be divided into identical left and right halves in only plane, exhibit bilateral symmetry.

RADIAL SYMMETRY



BILATERAL SYMMETRY

LEVEL OF ORGANISATION OF CELL IN BODY

* all members of animalia are multicellular and they exibit different level of organisation.
*cellular level-in sponges the cell are arranged in loose aggeregation.
   tissue level- in coelentrata the cell arrangement are more complex. here, the cell performing the                             same function are arranged into tissue.
   organ level-in platyhelminthes the tissue are grouped together  to form organs. each organ                                       specialised for a particular function.
   organ system level-in animals like annelida,arthropods,mollusca,echinodermata and                                               chordates,organ are associated to form funtion system. each system concern with a                              specific physiological function.this is called organ system level.
*in organ system level, the organism are classified on various basis like open and close circulatory system, complete and incomplete digestive system etc.



Monday 28 December 2015

ALTERNATION OF GENERATION IN PLANTS

Different plant group complete their life cycle in different patterns, e.g.- angiosperm complete their life cycle in two phases- a diploid sporophyte  plant body and the other haploid gametophyte, the two follow each other rigidly. this phenomenon is called alternation of generation.
   
     Life cycle of other plant group can be of following patterns-
1. Haplontic- there is a single vegetative individual or somatic phase. it is haplod and it is often called gametophyte. the haploid plant body may be unicellular, colonial or multicellular.

2. Diplontic- there is a single somatic  phase or vegetative individual. it is diploid  and is often called sporophyte though it produces gametes in its body or sex organ.

3.this type of life history involves the  sequential recurrence of two well developed somatic phase or vegetative individuals, gametophyte and sporophyte. the sporophyte. the sporophyte possess  diploid chromosome number(2n). meiosis takes place in it at the time of formation of  meiospors. the haploid meiospores germinate to produce haploid gametophyte. the gametophyte produces gametes.fusion of gametes produces zygote which develops in sporophyte. this is called alternation of generation.

Tuesday 15 December 2015

ANGIOSPERMS

* the sporophylls are aggeregate to form flowers, angiosperm are also called flowering plant.
*the pollen grain and ovule develops in specialised structure called flower.
*the seeds are enclosed by fruits.
*it has wide range of habitat, except sea because only two species are found there ZOSTERA and THALASSIA
*they range in size from tiny ,almost microscopic WOLFIA to tall tree of EUCALYPTUS
* pollination is through several agencies but most prominent is by insects.
*pollen reach stigmatic surface found at the tip of the carpell.
*female gametophyte develops upto 8 nucleate stage.
*archegonia are absent . instead there is one oosphere surrounded by two synergids that attracts and bring the pollen grains.
*there is double fertilization. one produces embryo,or new sporophyte, the other forms primary endosperm cell.
*endosperm is formed through triple fusion and generally triploid.
*fertilized ovules ripen into seeds. the seeds are covered by fruit. a fruit is technically a ripened ovary.
*xylem contains vessels.
*phloem possessses sieve tubes and companion cells.*secondry growth occurs in stem and root of some angiosperm, placed in group dicots.
*angiosperm are divided  into two sub-groups-
   1. dicotyledonous
   2. monocotyledonous


1. dicot-it is characterised by the presence of two cotyledons in seed,
                generally reticulate venation in leaves,
                concentric tissue in the stem with open vascular bundle arranged in a ring,
                penta or tetramerous flowers.
                e.g.- pea, rose, mulsard, eucalyptus etc

2. monocot- it is characterised by the presence of single cotyledons in seed.
                    generally parallel venetion in leaves
                    scattered closed vascular bundle in stem
                    trimerous flower
                    e.g.- banana, cereals, palms,grasses, bamboo etc.




GYMNOSPERMS

*gymnos means naked and sperma means seed, hence gymnosperm are those plants in which the ovules are not enclosed by any ovary wall.
* it includes medium size trees,tall trees and shrubs.
*SEQUOIA is the tallest tree among gymnosperm.
*it generally posses tap root
*PINUS root has association of fungus called mycorrhiza
*CYCUS root is coralloid and has association with cyanobacteria which helps in nitrogen fixation.
*stem are unbranched in CYCUS and branched in PINUS,CEDRUS.
*leaves may be simple or compound.
*in conifers , the needle like leaf reduce the surface area, their thick cuticle and sunken stomata also      help to reduce water loss.
*gymnosperms are heterosporous, they produce microspore and megaspores.
*spores are produced within sporangia that are borne on sporophylls, which are arranged spirally        along an axis to form lax or compact or strobili or cones. *the cone bearing microsporophylls and microsporangia are called male strobili.
* male strobili produces pollen grain
*the cone bearing megasporophylls and megasporangia are called female strobili.
* in PINUS , male and female cones develops on same tree.
*in CYCUS,male and female cones develops on different tree.
*megaspore mother cell(MMC) differentiate from one of the cell of nucellus, nucellus is protected by ovule, the ovule clustered to form female cone. this MMC develops 4 megasporangium one of which develops into multicellular female gametophyte bear two or more archegonia or female sex organ.
* male and female gametophyte do not have free living existance, they remain wthin sporangia.
*after fertilization zygote develops into an embryo and the ovules into seeds, seeds are not covered.

CYCAS


PINUS




GINKGO

Monday 14 December 2015

PTERIDOPHYTS

*they are the first  terrestrial plant to posses vascular tissue i.e. xylum and phloem.
*
they are soil binder.
*they are used as medicine.
*they are used as ornamental plants.
*they grow in cool, damp and shady places.
*the dominant phase of pteridophyte are sporophyte. in bryophytes it is gametophyte.
*plant body is differentiated into true root, stem and leaf.
*leaf may be microphylls (SELAGINELLA) or macrophylls (FERNS)
*the sporophyte bear sporangia that are subtended by leaf like appendages called sporophylls.
*in some cases sporophylls may form distinct compact structures called strobili or cones.(SELAGINELLA, EQUISETUM)
*sprangia produces spore and spore germinate into prothallus.these gametophyte required cool, damp shady place to grow.
*sexual reproduction by antheridia and archegonium.
*after fertilization zygote produce sporophyte,which is dominant phase.
*the plants which have similar spores are called homosporous.
*the plants which have dissimilar spores are called heterosporous.
*female gamete are larger than male gamete.
*zygote develops into young embryo, it is the precursor to seed habitat.
*pteridophytes are further divided into four classes:-
1.PSILOPSIDA- Psilotum
2.LYCOPSIDA- Selaginella, Lycopodium
3.SPHENOPSIDA- Equisetum4.PTEROPSIDA- Dryopteris,Pteris,Adiantum


SELAGINELLA



LYCOPODIUM

EQUISETUM



DRYOPTERIS

PTERIS

ADIANTUM



PSILOTUM


MOSSES


POLYTRICHUM


SPHAGNUM


FUNARIA

*the predominant phase of mosses is gametophyte, which consists of two stages-the protonema and the leafy stage.
*protonema directly developes from spore it is creeping,green,branched and filamentous stage.
*leafy stage develops from secondary protonema as a lateral bud.
*leafy stage bear sex organ.
*leafy stage have slender axes bearing spirally arranged leaf, attached to soil by multicellular and branched rhizoids.
*vegetative reproduction by fragmentation and budding in secondary protonema.
*sexual reproduction by antheridia and archegonia, after fertilization zygote develops into sporophyte
*sporophyte consists of foot seta and capsule.
*e.g.- Funaria, Polytrichum, Sphagnum

LIVERWORT

*the liverwort grow in moist habitat such as marshy ground,bar of trees etc
*the plant body of liverwort is thalloid.
*asexual reproduction by fragmentation of thalli or by formation of specialised structure called gemmae.
gemmae are green,multicellular, asexual bud which develop in small receptacles called gemma cups located on thalli.
*the gemmae become detached from parent body and germinate to new individual.
*in sexual reproduction male and female organ are produced on same or different thalli.
*the sporophyte are differentiated into foot, septa and capsule.
*after meiosis spore are produced within capsule.these spore germinate to form free living gametophyte.
*
e.g.- Marchantia

BRYOPHYTES

MOSSES

LIVERWORT
*bryophyta are called the amphibians of plants because they live on soil and reproduce in water.
*it includes mosses and liverwort.
*they play an important role in plant succession on bare rocks.
*plant body is different from algae, it is thallus like and prostrate or erect, and attached to the substratum by unicellular or multi-cellular  rhizoids.
*the main plant body of bryophytes are haploid, it produces gametes, hence it is called gametophytes.
*sex cell in bryophytes are multicellular.
*male sex organ is called antheridium, produces biflagellate antherozoids.
*female sex organ is called archegonium,which is flask-shaped , produces single egg.
*fusion of gametes take place in water and forms zygote.
*zygote does not undergo reduction division and forms multicellular body called sporophyte.
*sporophyte is not free living, it is attached to gametophyte for food.
*sporophyte undergo meiosis division and forms haploid spores,these germinate to produce gametophytes.
*some mosses are edible by some animals.
*some bryophytes are used as fuel.
*mosses along with lichen are the first organism to colonise on rock, they decompose rock and make it suitable for growth of higher plants.

RHODOPHYCEAE











*commonly called as red algae.
*r-phycoerythrin is the red pigment  present in this algae/
*they are marine habitat ant mainly found in warm places.
*some algae have complex body structure.
*they live on surface and depth of ocean too.
*food is stored as floridean starch.
*vegetative reproduction by fragmentation.
*asexual reproduction by non-motile spores.
*sexual reproduction by gametes, which is oogamous.
*e.g.- Polysiphonia, Porphyra, Gracilaria, Gelidium

PHAEOPHYCEAE


*these are called brown algae.
*they are marine habitat.
*they show great variation in size e.g. Ectocarpus are simple branched and filamentous, and Kelp profusely branched and approx 100 m long.
*it has chlorophyll a and c.
*it has other pigments like carotenoids and xanthophylls.
* food is stored as complex carbohydrate,laminarin or mannitol.
*vegetative cell has gelatinous coating of algin.
*the plant body is usually attached to the substratum by a holdfast, and has stalk, the stipe and leaf like photosynthetic organ-the frond.
*vegetative reproduction by fragmentation.
*asexual reproduction by biflagellated zoospores that are pear shaped and two unequal laterally attached flagella.
*sexual reproduction by gametes, they may be isogamous, anisogamous or oogamous.
*e.g.- Ectocarpus, Dictyota, Laminaria, Sargassum, Fucus etc



]