Chapter_1_Living_World__Unit_2.13.pptx

Growth Reproduction Metabolism
Mountains & sand mounds do grow by deposition but
living things grow from inside.
STILL
Growth cannot be taken as defining property of life.
Reproduction is the characteristic property of organisms,
however organisms who do not reproduce like mules,
worker bees, infertile human couples do exist hence even
Reproduction also cannot be the defining characteristic
of life
Sum total of all reactions occurring in the body of an
organism is called as metabolism.
feature of life form.
Non-living objects do not metabolize hence
METABOLISM & CELLULAR ORGANIZATION is the
defining feature of life form.
Consciousness (Irritability/Responsiveness) is also the
defining property of a living organism.

Homeostasis
Expression of Energy
Adaptation
Are also some of the important properties of life

2.13 Five kingdom system of classification
 Robert W. Whittaker has classified the living organisms into
5 kingdoms namely;
 The criteria includes cell organisation, body organisation,
mode of nutrition and life style.
Monera Protista Fungi Plantae Animalia
Chapter 2. Systematics of Living organisms

Nostoc (cyanobacteria)

 The Kingdom Monera includes microscopic and prokaryotic organisms
possessing a primitive type of nucleus called nucleoid.
 They also posses plasmids (extra-chromosomal, autonomously, self-replicating
minichromosomes)
 The mode of nutrition is either autotrophic or heterotrophic. The autotrophs
are either Photoautotrophs (Cyanobacteria) or Chemoautotrophs (Thiobacillus).
Kingdom : Monera
 Reproduction is asexual, either by fission or budding. Sexual reproduction
is absent.
 They do not possess membrane bound cell organelles.
 Monerans are either unicellular (Eubacteria) or filaments (Cyanobacteria --Nostoc).

 Cell wall is made up of peptidoglycans (murein – polymer of sugar &
aminoacids).
Kingdom : Monera
 On the basis of evolution bacteria are classified into
Archaebacteria Eubacteria
Extremophiles
Halophiles Thermophiles
 Found in extreme environments
hence called
Found in salty
lakes
Found in hot
water springs
Eg. Methanogens

Kingdom : Monera
Autotrophs Heterotrophs
Chlorobium
Chromatium
Chemosynthetic
Sulphur bacteria
Photosynthetic
Eubacteria/Truebacteria
 Cell wall made up of peptidoglycans, they are of two types
 Mostly multicellular, fresh water forms, covered by
mucilagenous sheath.
 Photosynthetic pigments are found, heterocysts for N2 fixation
(Azotobacter)
Decomposers
Anaerobes Pathogens
Lactobacilli
Streptomyces – antibiotic
production
Causing TB,
Cholera, Typhoid

Kingdom : Protista

They are unicellular, eukaryotic organisms with a well
organized nucleus.
Reproduction is both by asexual and sexual methods.
There are following types of protists;
Kingdom : Protista
Plant like Protists Dinoflagellates
Fungi like Protists
Animal like Protists
Euglenoids
Nutrition is both autotrophic and heterotrophic. Heterotrophic
nutrition is parasitic or saprophytic.
They possess membrane bound cell organelles like
mitochondria, endoplasmic reticulum, Golgi complex etc.

Kingdom : Protista
They are termed as chrysophytes, commonly termed as phyto-
planktons, microscopic & mostly photosynthetic (major producers).
Body wall of Diatoms is made
up of two soap box like fitting
(silica).
Chrysophytes -- Plant like Protist -- Diatoms
Diatomaceous earth is the
shells left behind for many
years, (granular in nature). It is
used in polishing & filtration.

Kingdom : Protista
Golden algae (Desmids) are also included, they show
planktonic existence.
Chrysophytes -- Plant like Protist -- Diatoms

Kingdom : Protista
Plant like protists -- Dinoflagellates
They are aquatic (mostly marine), photosynthetic with wide range
of pigments (yellow, green, brown, blue, red ).
Cell wall made up of
cellulosic stiff plates. They
have a pair of flagella
Gonyaulax is responsible for
red tide. It makes even sea
appear red fatal for marine life.

Kingdom : Protista
Protozoans Animal like Protist -- Amoeba
They are termed as protozoans, lack cell
wall, heterotrophs (predators/parasites), believed
to be primitive animal forms.
Amoeboid protozoan have pseudopodia as locomotory organs.
Entamoeba is endoparasite (amoebic dysentry).
Paramoecium is ciliated
protozoan, gullet (cavity) open
on cell surface. Plasmodium
is a sporozoan protozoa
(malaria).
Trypanosoma is flagellated protozoan
(sleeping sickness). Trypanosoma
Plasmodium Paramoecium

Kingdom : Protista
Protozoans Animal like Protist -- Amoeba
They form four major groups namely;
Amoeboid protozoans – psuedopodia, few
like Entamoeba are parasitic
Flagellated protozoans – free living/parasitic
eg. Trypanosoma
Ciliated protozoans – they have a cavity (gullet) which opens
outside, coordinated movement of rows of cilia causes water
laden food to be steered in the gullet.
Sporozoans – have an infectious spore like stagein life cycle,
plasmodium is most notorius.

Kingdom : Protista
Fungi like Protists – Slime moulds
Commonly form the group
Myxomycetes, saprophytic,
cell aggregates form a large
cell mass called plasmodium
(not a malarial parasite).
Spores produced by
plasmodium are very tough &
survive harsh conditions.

Kingdom : Protista
Euglenoids
They lack cell wall but are covered by
Pellicle (tough proteinaceous cover).
They are biflagellate, one short, other
long,
In the absence of light they are
heterotrophs but have pigments similar
to higher plants.

Kingdom : Fungi
They are eukaryotic heterotrophs (mostly saprophytic, few parasitic or
predators, extra cellular digestion), unicellular or multi-cellular
organisms found in warm & humid places.
Unicellular forms have a
protoplast with many nuclei.
(Rhizopus, Saccharomyces (yeast)).
Multicellular forms are made
up of hyphae (long thread like
structures).
Multicellular forms are made
up of hyphae (long thread like
structures). Body is filamentous
forms mycelium.

Reproduction is vegetative, asexual (fragmentation/fission/budding) &
sexual.
Some fungi are symbiotic (Lichens, Mycorrhizza with roots of higher plants)
Kingdom : Fungi
Hyphae may be septate/aseptate,
uninucleate/multinucleate
Aseptate, multinucleate hyphae are
called coenocytic hyphae.
The cell wall is made of chitin
(polysaccharide) or fungal cellulose.

Kingdom : Fungi
Penicillium (Penicillium notatum) produces antibiotic, harmful fungi
causes diseases in plants & animals eg. Puccinia.
They are classified on the basis of structure, mode of spore
formation & fruiting bodies into
Ascomycetes Basidiomycetes
Phycomycetes Dueteromycetes
Mushrooms are consumed as food, bakery, breweries.
Uses
Classification

Algal fungi, coenocytic
Eg. Mucor, Rhizopus, Albugo (mustard parasite)
Kingdom : Fungi
Phycomycetes
Ascomycetes
Sac fungi, multicellular, Hyphae branched
and septate, Decomposers/parasites or
coprophilous (grow on dung)
Morels & Truffles (delicacies), Neurospora
(genetic & biological assays)
Eg. Aspergillus, Penicillium, Claviceps,
Saccharomyces
Mucor Rhizopus
Aspergillus Penicillium
Saccharomyces Neurospora

Basidiomycetes Dueteromycetes
Club fungi, branched septate hyphae, Imperfect fungi, Reproduce only
asexually
Alternaria
Agaricus (Mushrooms)
Kingdom : Fungi
Puccinia (rusts)
Ganoderma (Bracket fungus)
Ustilago (smuts)
Collectotrichum

Kingdom : Plantae
This kingdom is dominated by autotrophs, but they do include
some semi-autotrophs, insectivorous plants also.
They are multicellular, eukaryotic, contain chlorophyll.
Cell wall is made up of cellulose. They exhibit alternation of
generations.
It is further divided in to
Cryptogamae/Cryptogams Phanerogamae/Phanerogams

Kingdom : Animalia
This kingdom is of heterotrophs, exhibit holozoic nutrition
This are multicellular, eukaryotic locomotory organisms.
This lack chlorophyll & cell wall, growth is determinate (definate
pattern).

2.14 Acellular organisms
Viruses
Named by Louis Pasteur (venom/poison), M. J. Beijernek called
them Virus after his observation of their migration in agar gel.
Being an infectious soluble agent, filtrate was thus called
contagium vivum fluidum.
Scientist Stanley demonstrated the inert
nature of virus outside host &
crystallization.
Historical Account
(not included in Whitaker’s five kingdom classification)
Composition
Viruses have a protein coat (capsid) around nucleic acid strand,
they lack their own cell machinery hence considered acellular.

Types of Viruses
As per genetic material they are of two types;
DNA viruses RNA Viruses
Capsid is made up of capsomeres, they are arranged in
polyhedral/helical forms.
Genetic material is single/double stranded RNA/double
stranded DNA.
Viruses infecting bacteria are termed as
bacteriophages/phages.
Disorders caused by viruses in plants/animals are;
Leaf curling / yellowing / mosaic formation
Small pox / Mumps / herpes to Common cold
Swine flu
AIDS

Viroids
Infectious RNA strands are called viroids.
Potato spindle tuber disease was found to
be caused by single stranded RNA without
Protein coat.
It is low molecular weight RNA, smaller than
viruses. (T. O. Diener).
Prions are abnormally folded
proteins which has caused
infectious neurological
diseases. (Eg. Mad cow disease in
cattle, Jacob’s disease in human).
Prions

Lichens
Lichens are a symbiotic association between algae & fungus.
Algal member is phycobiont, fungal component is called
mycobiont.
They are found in extreme environments but still are sensitive
to pollution. They play important role in soil formation (acid
production).

24.Lichens
Lichens are close associations of two different organisms of which one is an alga and the
other is a fungus.
The algal component of the lichen is called phycobiont or photobiont while the fungal
component is known as mycobiont.
On the basis of thallus organisation three types of lichen, viz.,crustose, foliose and
fruticose have been recognized.
Crutose lichens occur as crusts on the rock or bark of tree. Graphis, Leanora and
Haematomma are the examples of crustose lichens.
Foliose lichens are dorsoventrally flattened leafy lichens. They are attached to
substratum by rhizoid-like structures called rhizines. Parmelia, Collema and Peltigera are
the examples of foliose lichens.

25.Economic importance of lichens
Lichens such as Lecanra esculenta and umbilicaria esculenta are used as food.
Parmelia is used in the preparation of chocolates and pastries.
Lichens such as species of Cladonia, Evernia and Parmelia are used as fodder.
Usnic acid which is obtained from Usnea and Cladonia is widely used as an antibiotic
against Gram positive bacteria.
Some lichens like species of Lobaria and Citraria are useful in the treatment of
tuberculosis. Parmelia is useful in the treatment of epilepsy.
Species of Evernia and Ramalina are used in the preparation of soaps and other
cosmetics.
26.Viruses
Viruses are ultramicroscopic, acellular highly infectious microorganisms.
Viruses are obligate parasites.They can multiply only in host cells.
Viruses are classified according to their hosts. They have been classified into three
groups, viz., Bacteriophages, plant viruses and animal viruses.
27.Viroids
viroids are small, circular, single stranded RNAs without protein coats.
Viroids cause disease in plants such as Citrus exocortis, Chrysanthemum stunt,
cucumber bale fruit, etc.

Chapter_1_Living_World__Unit_2.13.pptx

Recommended

Recommended

More Related Content

Similar to Chapter_1_Living_World__Unit_2.13.pptx

Similar to Chapter_1_Living_World__Unit_2.13.pptx (20)

More from Rahul Badve

More from Rahul Badve (20)

Recently uploaded

Recently uploaded (20)

Chapter_1_Living_World__Unit_2.13.pptx