Chapter 1
Biodiversity
- Variety of life forms existing on Earth
- Maintains the ecological balance on earth
- Preventing species extinction is one way to preserve biodiversity
Characteristics of life:-
1. All living organisms grow:-
Growth is from inside the living organisms
2. Reproduction:-
Process by which living organisms produce new organisms similar to themselves.
Modes of reproduction:-
Asexual and sexual
It is not mendatory that all living organisms reproduces, however it is known that no non-living organism can reproduce.
3. Metabolism:-
Set of life sustaining chemical reactions taking place inside the body of a living organism.
Metabolism is a defining feature of all living organisms without exception, isolated metabolic reactions on vitro are not living things but living reactions.
4. Cellular organisation of the body
All living organisms are made up of cells.
5. Consciousness:-
Ability to sense the surroundings and response to them.
Thus living organisms are self replicating and response to them.
self regulating interactive system capable of responding to external stimuli.
Nomenclature and identification:-
Nomenclature:- Process of naming living organisms such that a particular organism is known by the same name all over the world.
Identification:-
Describing an organism correctly so that the organism can be named.
Nomenclature is possible only when identification is done.
Binomial Nomenclature:-
System of providing name with two components to a living organism.
This naming system was given by Carolus Linnaeus
Two components:-
Generic name and specific epithet.
Example :-
Mangifera indica (mango)
Solanum tuberosum (potato)
Panthers leo (the lion)
Musco domestica ( the house fly)
Homo sapiens (the humans)
Triticum aestivum (wheat)
Panthera tigris (the tiger)
Panthera pardus (the leopard)
Universal rules of Nomenclature:-
- Generally in Latin or Latinised
- Written in italics /underline.
- The first word represents genus while the second one denotes the specific epithet
- Genus starts with a capital letter, while species with a small letter.
Is it possible to give binomial name to all living organisms?
No it's not possible to study each and every living organism.
Solution will be classification
Classification of living organisms:-
Process of grouping things into categories based on some easily observable characters.
Characteristics:- Features/ quality belonging to particular organism.
Why do we need classification?
It is not possible to study about each existing living organism in detail.
Classifying organisms into groups make it easier to know about different life forms.
Classification help us to understand the evolution of all life forms to a large extent.
Scientific naming of organisms is based on classification.
What should be the basic of classification?
The more basic characteristics should be considered for classification.
Taxa :- scientific term for categories - into which organisms are grouped.
Taxa can indicate categories ta very different levels
Taxanomy
Classification of living organisms into different taxa based on characteristics.
Systematics:-
Branch of science which deal with systematic arrangement of organisms and relationship among them.
Taxanomic hierarchy:-
A part of overall taxanomic arrangement
Taxanomic categories together constitute taxanomic hierarchy.
Taxon (Taxa):-
Each taxanomic category represents a unit of classification termed as rank/taxa.
Group > category> rank/taxon.
Hierarchy classification:-
The more similarities , the more closely they are related.
Species :-
Basic unit of classification of organisms.
Group of closely resembling organisms which are capable of reproducing each other and produce offspring.
Example:- humans belong to species - sapiens
Mango belong to species - indica
Genus:-
Group of closely related species.
Species of one genus are more closely related to each other than to species in any other genus.
Example:
1 potato (Solanum tuberosum) and bringal (Solanum melongata) both belong to same genus I.e. Solanum.
2. Lion (Panthera leo) , Tiger (Panthera tigris) and leopard (Panthera pardus) all belong to same genus.ie. Panthera.
Family -
Group of related genera with still less number of similarities as compared to genus and species.
Genus in one family are more closely related to each other than to genus in any other family.
Example:-
Solanum, Petunia, Datura are three genus and belong to same family "solanaceae".
Panthera and Felia (cat) belongs to same family " Falidae"
Order:-
Group of related families which have few similar characters.
Families in one order are more closely related to each other that family in any other order.
Example:-
Convolvulaceae and solanaceae are two families belonging to same order I.e. polymoniales.
Felidae and canidae are two families belonging to same order I.e. carnivora.
Class :-
Group of related orders which have few similar characters.
Orders in one class are more closely related to each other than to orders in any other class.
Example:- Primata and Carnivora are two orders belonging to same class Mammalia.
Phylum:-
Groups of related classes of animals with some common features like
Presence of notochord
Dorsal , hollow neural system.
Example:- mammals along with fishes , reptiles, birds, amphibians belong to same phylum I.e chordata.
Division:-
Group of related classes of plants with some common features.
Example:- Dicotyledonae and monocotyledonae are two classes of plants belong to same division I.e. angiosperms.
Kingdom:-
Highest category of classification.
earlier there was two kingdom
Plantae- includes all plants from various division.
Animalia- includes all animals fro. Various phyla.
Taxanomical Aids:-
Collection of specimens of plants and animal species is essential and is the prime source of taxanomic studies.
Procedures and techniques to store and preserve the information as well as specimen is called taxanomical aids.
Some taxanomical aids:-
- Harbarium
- Museums
- Botanical garden
- Zoological park
- Key
Harbarium:- store house of collecting specimens that are dried , pressed and preserved on sheets.
Botanical garden:- Area where collection of living plants for references is taken place.
Museum:- collection of preserved plants and animal specimens for study and reference.
Zoological park:-
Area where wild animals are kept in protected environment under human care.
Key:-
Taxanomical aid used for identification of plants and animals based on similarities and dissimilarities.
Based on contrasting characters
- Pair of contrasting characters - couplet.
- Each statement in a key is called lead.
- Separate keys are required for each taxon.
Flora:-
- Contain account of habitat and distribution of plants of a given area.
Monographs:- contain information on any one taxon
Manuals:-
- Useful in providing information for identification of names of species found in an area.
Catalogues:-
- Useful in providing information of flora and fona of zoo
Thankyou....
More to know:-
Keys to identification of plants
Identification is the process of determination of exact position of an unknown specimen in the set plan of classification.
It also leads with the nomenclature of that specimen.
Plant identification is carried out with the help of duly identified herbaria, botanical gardens, taxonomic literatures, identification keys and a variety of other ways
A Herbarium:-
A Herbarium is a collection of well dried, pressed and properly preserved plants which are correctly identified, labelled and systematically arranged according to an approved system of classification.
The plants are mounted on a sheet of paper and the plants which are not suitable for pressing and mounting like succulents, fossil seeds, etc. Are either preserved in FAA (Formaldehyde acetic acid) or dried and stored in large containers
These preservations form a part of permanent record.
Herbaria are available for reference in taxonomical, comparative and morphological studies.
The unknown specimens are compared with the herbarium specimens and identified by the subject expert.
History :
Caesalpino was the first to preserve the plant materials studied by him and soon after this, importance of herbaria was realized.
With the progress in taxonomic field, simple drawings, photographs and written descriptions proved insufficient to provide morphological and development details about the plants, this making the herbarium specimens indispensable. Inspite of identification, herbaria serve many other purposes.
1. They provide scientific information on the plants to students or layman by exhibition, trainings etc.
2. They serve as a reference material for modern taxonomical research.
3. Herbaria are national plant wealth repositories.
Some important Herbaria are listed below:
National Herbaria :
1. Central national Herbaria, Kolkata
2. Herbaria of Forest Research Institute (FRI) Dehradun
3. Madras Herbarium, Coimbatore
4. Harbarium of national botanical research institute (NBRI) , Lucknow.
Harbaria of other Countries:
1. Royal Botanical Garden, Herbarium, Kew, Britain
2. Herbarium Nationale de Historie Laboratories de Phanerogamie, Paris, France.
3.British Museum of National history, London ,Britain.
4. Herbaria of Department of systematics and plant Geography of BIASL, Russia.
B.botanical gardens:-
A botanical garden is a place where living plants are grown, and maintained to keep the record of local and regional flora for biosystematic and research studies.
Botanical garden are of multiple significance with special reference to the comparative study of plants assited by Herbaria.
Thus botanical gardens provide materials for taxanomic studies, categorization, nomenclature and other investigations.
They also serve as acclamatization centres for various economic plants used for horticulture and agriculture etc.
History: History of botanical gardens is very old. In ancient times, plants were grown for the purpose of food and medicines.
The Romans , the Chinese and the Persians were very fond of gathering and growing plants for various purposes.
The first and the oldest botanical gardens were established in Pisa and Padua parts of the world.
Some important ones are listed below.
1. Royal Botanical Garden ,Kew, England,
2. Oxford Botanical Garden, England.
3. Royal Botanical Garden, Edinburg, Scottland
Botanical garden of India
1. Indian Botanical Garden, Kolkata
2. Iloyd Botanical Garden, Darjeeling
3. National Botanical Research Institute, Lucknow.
C. Taxonomic literature
Taxonomy has one of the oldest and most voluminous literature used by the scientists for identification of an unknown plant, solution of a nomenclature problem, or for a detailed taxonomic study of plants.
The ancient literature was in Latin which is now available in English, Russian, France, Spanish and German.
Following are some of the most important and valuable sources of taxonomic literatures.
1. Indexes:- These are the catalogues prepared to depict the synopsis or abstracts of work done in the subject.
The publications may include the list of plants with their botanical name or a brief summary of the paper.
New researches are regularly added in them. Some important ones are:
i. Grey Herbaria Index (1896) on vascular plants.
ii. Catalogue of the library of Royal Botanical Gardens London (1919).
iiii. Index Kewensis Plantarum Phanerograma(1893) includes generic and botanical names of the seed plants
iv. A dictionary of flowering plants in India. CSIR ,New Delhi.
V. The standard Cyclopedia of Horticulture (1939) by Bailey, L.H.
2. Floras and Manuals :
Floras are description of plants from a specified geographical regions.
The area may be a country or may be as small as a small mountain.
Like wise, the type of plants may also be restricted e.g., vascular plants, flowering plants or non-vascular plants etc, Flora may include identification keys.
some of the important floras are :-
(i) The Flora of British India By Sir J.D. Hooker
(ii) Genera Plantarum by Bentham and Hooker
(iii) Flora of Delhi by J.K. Maheshwari (1963) (iv) India Forest Records, FRI, Dehradun
(v) The Flora of the Presidency of Bombay by Cook, T (1901-08)
Manuals contain more exhaustive study on each taxon i.e. description, ecological data, identification keys, glossary of technical terms.
3. Monographs and Journals :
Monograph is a basic literature of taxanomy.
A monograph is a comprehensive study of a particular taxonomic group (genus or family) as gathered from all available ‘ sources throughout the world.
This information is reviewed, revaluated, analyzed and finally incorporated in the manuals.
A few are listed below :
Indian trees by Brandis, D. London
some Beautiful Indian Climbers and Shrubs by Bor and Raizada (1954)
Flowering plants of India, Nepal and Bhutan by Nailhani.
JOURNAL is a Published literature by a society, institute or university containing the latest advances in specific fields
A few are listed below:
(i) Indian forester by FRI Dehradun
(ii) Records of Botanical survey of India by B.S.I. Calcutta
(iii) Bulletin of Botanical survey of India by B.S.I., Calcutta
Dictionaries and Glossaries:-
A botanical dictionary may list and describe all the known genera of a plant group. A glossary is an alphabetical list of botanical terms with their interpretations.
(I) the wealth of India- a dictionary of Raw materials and Industrial Products by CSIR.
(ii) a glossary of Botanical Terms with their derivation and acent, London.
5.Taxonomic keys: these are described here in details.
TAXONOMIC KEYs_
Taxonomic keys are artificial analytical arrangements useful in identifying an unknown plant.
It is a more convenient method to identify a specimen than to shuffle through a large number of specimens in a herbarium untill a match is found.
Keys are prepared on the basis of the process of elimination by using easily detactable and reliable diagnostic characters.
So, the unknown plant to be identfied must be studied in details and all its diagnostic characters must be noted and listed in a proper sequence
. Keys provide preliminary identification which must be confirmed by using some athentic literature.
Two types of keys are used now a days : Single acess or sequential keys and multiaccess or multientry keys.
A. SINGLE ACCESS OR SEQUENTIAL KEYS
it is the most conventional and most acceptable type of keys and are also known as dichotomous key or diagnostic keys.
It consists of several Steps in a sequence and each step has a pair of contrasting choices or character.
Each pair of choice is called a couplet and each statement ofa couplet is called a lead at each step, one lead of a couplet will be accepted and the other rejected and with this one or more taxa are eliminated.
The first contrasting characters in each couplet are usually the best contrasting characters and are known as primary key characters and the others that follow the lead are called secondary key characters and the others that follow the lead are called secondary key characters.
There are two major types of dichotomous keys
Yoked or indented Keys
Bracketed or parallel keys.
These are explained by an example in which keys are prepared by using 5- couplets for the identification of six genera of family Ranunculaceae.
Yoked or Indented Sequential Keys :
This type of key is usually used in floras and manuals.
This is characterised by the placement of two lead of a couplet at a fixed distance from the margin.
The initial couplet is close to the margin and the subsequent one gradually move away from the margin. It is explained by the following example :
1. Fruit an achene
2. Calyx differentiated from Corolla
3. Petals with nectary at the base.............. Ranunculus
3. Petals without nectary at the base........... Adonis
2. Calyx not differentiated from Corolla
4. Plants WOOdY....
4.plants herbaceous.............. Anemone
. 1. Fruit a follicle
5. Spur present...... ....Delphinium
5. Spur absent.......... Caltha
6) Bracketed or Parallel Sequential Keys :
It is characterized by the placement of two leads of each couplet always together having the same distance from the margin.
- Fruit an achene (2)
Fruit follicle’ (5)
2. Calyx differentiated from
carolla (3) 2. Calyx not differentiated from corolla(4)
3. Petals with
nectary at the base .............. Ranunculus
3. Petals without nectary at the base .......... Adonis. ,
4. Plants woody.......clematis
4. Plants herbaceous......Anemone
5. Spur present.... Delphinium
5. Spur absent..... Caltha
Some important rules for the construction of sequential keys
1. Keys should be strictly dichotomous.
2. Contrasting characters should be used in two leads
3. To avoid confusion, initial letter of each lead in a couplet should be identical
4 Two successive couplets should not begin with same word.
5. Macroscopic and morphological characters should be used in keys.
MultiACCESS OR MULTIENTRY KEYS
These are also known as punched cards keys.
These keys are prepared by making use of specific cards which ' are punched at a definite place for a particular taxon and for a particular character.
Various cards are then piled up and common perforations (punchings) shows the taxon to which the new specimen belong. Depending upon the kinds of punching in the cards, keys are of two types :
(a) Body Punched Cards Keys :For the preparation of such keys, at first attributes are selected for the identification of all taxa.
Then equal number of cards are taken and one attribute at the top of one card is written.
All the taxa (for which key is prepared) should be printed in a vertical row on each card as shown in Fig. 4.1
Now take one card and to indicate the presence of the attribute (character) printed at the top, punch the card against the taxa.
Donot punch the taxa in which that attribute is absent e.g., For bisexual character punch all the six taxa but donot punch against Zea mays as it is not herbaceous, likewise punch the second card over the first and repeat this process untill only one hole remains visible
The name of the plant is now identified, i.e. against which the hole is visible
Edge Punched Cards :
In the preparation of edge punch cards, taxa is written at the top and attributes are listed in vertical rows on each card and hence card is punched against the attribute.
Finally the punched attributes shown by the particular taxa are cut and connected with edge and thus unknown plant is identified.
chapter 2
Biological classification
Classification of living organisms
Classifying living organisms into groups based on certain set of characteristics.
Characteristics:-
Features /quanlity belonging to a particular organism
Aristotle 's attempt to classify living organisms:-
Aristotle classified animals based on habitats:-
- Land (terrestrial)
- Water (aquatic)
- Air(aerial)
Plants on based of size:-
- Herb
- Shrubs
- Trees
2-kingdom classification:-
Carl Linnaeus introduced a two kingdom classification
- Plantae
- Animalia
Basis of two kingdom classification
Plantae:-
- Immobile
- Mostly prepare their own food.
Animalia:-
- Mobile (have some means of classification)
- Intake food.
Limitations of two kingdom classification:-
- No distinction between
- Eukaryotes and prokaryotes
- Unicellular and multicellular
- Photosynthetic and non photosynthetic
- Many organisms did not belong to any of the two kingdoms bacteria, fungi, viruses.
Whittaker's classification of life forms:-
- Robert Whittaker's basis of classification
- Cell structure
- Body organisation
- Mode and source of nutrition.
- All living organisms were broadly classified into 5 groups as kingdom.
5- Kingdom classification:-
Monera, Protists, Fungi, Plantae, Animalia.
Monera - Characteristics
- Oldest life forms
- Prokaryotes
- - No defined cell organelle or nucleus.
- Unicellular
- - made up of one cell.
Some are autotrophic, while some are heterotrophic.
Autotrophic :-
- prepare their own food
- Photosynthetic autotrophs
Chemosynthetic autotrophs
Heterotrophic - depend on other for their food.
Monera:- Bacteria
- Appear in variety of shapes and sizes
- Inhibits soil, water, radioactive waste and deep portion of earth's crust, deep oceans, hot springs, snow desert.
- Live in plant/animal bodies.
- Symbiosis:- A relationship of mutual benefit between two organisms.
Bacteria: types:-
4 types based on shapes-
- Coccus - spherical
- Bacillus - cylindrical
- Vibrium - comma shaped
- Spirillium - spiral
Some bacteria:-
Archaebacteria , Eubacteria, Mycoplasmas, Cyanobacteria, E coli
Archaebacteria:-
- Oldest bacteria
- Rigid cell wall
- Habitat:-
- Extreme habitat
- - high salt concentration
- - high temperature
- -oxygen free marshy areas
Types:-
- high salt concentration - Halophiles
- - high temperature - Thermophiles
- -oxygen free marshy areas - Methanogens
- Ex:- Methanobacteria, Methanococcus, Methanothermis.
Nutrition:-
- some are heterotrophs, many as chemoautotrophs.
Eubacteria:-
- True bacteria
- Rigid cell wall
- Flagellum is present.
Habitat:-
- Can be found anywhere including human beings.
- Many occur in moist habitat.
Nutrition:-
Photosynthetic autotrophs:-
- Prepare their own food in presence of sunlight with chlorophyll.
- Cyanobacteria/ Blue green algae.
Chemosynthetic autotrophs:-
- prepare their own food with the help of chemicals( oxidizing nitrates,nitrites, ammonia)
- Help in recycling nutrients.
- Saprophytes:-
- Decomposers
- Feed on dead and decaying organisms / matter
Parasite:-
Live either in or on the host body and thrives nutrients from organism.
Cyanobacteria:-
- Blue green algae
- Cyano - Blue and hence termed as cyanobacteria.
- Perform photosynthesis.
- Responsible for enriching atmosphere with oxygen.
- Considered ancestors of all life forms on earth.
Heterotrophic Eubacteria:-
- Decomposers:-
- Bacillus, streptomyces, pseudomonas
- Curd from milk
- Antibiotics
- Nitrogen fixation
- - Rhizobium
Pathogens:-
- Disease causing bacteria
- Typhoid:- Salmonella. typhi
- Cholera :- Vibrio cholerae
- Tetanus:- Clostridium tetani
- Tuberculosis (TB) :- Mycobacterium tuberculosis
- Syphilis:- Trepanema pallium
E- coli :-
- Rod shaped bacteria.
- Found in lower intestine of worm - blooded organisms
- Most E- coli strains are harmless, but some can cause serious food poisoning in humans.
Mycoplasm:-
- Parasitic bacteria
- No cell wall
- Smallest living cells.
Habitat:- Human respiratory/urinogenital tract and blood smear
Diseases:-
- FIA (Feline infection Anemia)
- Mycoplasma pneumoniae :- Pneumonia
Monera Reproduction:-
Bacteria can reproduce by two modes-
Asexual mode
- Fission , -spore formation
Sexual mode
- DNA transfer
Overall significance:-
- Important decomposers
- Produce food and medicine
- Recycle nutrients
- Fertilize fields
Protista:- characteristics
- Eukaryotes
- Specific membrane bound cell organelles and distinct nuclei.
- Mostly unicellular
- Made up of one cell.
- Some are autotrophic while others are heterotrophic
Autotrophic - prepare their own food.
Heterotrophic:- Depend on others for their food.
- Prefer moist and aquatic habitat.
- Reproduce both sexually and asexually.
Protists:- link with other kingdom
Plant-like protists
- Algae
Animal like protists
- Protozoa
Fungus like protists
- Slime mould and water moulds.
Protists:-
Groups under protists:-
- Chrysophytes,
- Dianoflagellates,
- Euglenoids,
- Slime mould and protozoans
Chrysophytes:-
- Diatoms and golden algae.
- Plant like protists
- Structure:- contain chlorophyll, carotene and xenthophylls
- Rigid cell wall made up of pectin/cellulose/silica
Habitat:-
- Aquatic
- Can be freshwater/marine
- Float passively in water.
Nutrition:-
- mostly photosynthetic
- Diatoms main producers of food in oceans.
- Store food as oil
- Few are heterotrophic eating small bacteria
Reproduction:-
- Mostly asexual
Diatomaceous earth:-
- Accumulation of cell wall deposits of diatoms over several years form diatomaceous earth
Uses:-
- filteration of oils and syrups
- Polishing
- Tooth pastes
- Facial scrubs
- Pest control
- Grain storage in agriculture
2. Dianoflagellates:-
- Protista with flagella (mostly 2)
- Longitudinal flagella
- Transverse flagella
- Neither plants nor animal like protista
Structure:-
- Contain chlorophyll /carotene/several group of xanthophylls.
- Complex cell covering , cortex is present.
- Light sensitive organelle, eye spot is found in some of them.
- Example:- Erythropsidium :- smallest known eye.
Habitat:-
- aquatic
- Can be fresh water/marine.
Nutrition:-
- Photosynthetic + ingestion of prey
- Oodinium , Noctiluca
Reproduction:-
- mostly asexual by means of fusion.
- Sexual mode seen only in some of them
Red tide:-
- Algal bloom
- The coloration of sea into red due to rapid multiplication of red dinoflagellates, Gonyaulase is termed as red tide.
- Chemicals released during this process is extremely harmful for survival of other aquatic life.
Euglenoids:-
- Share characteristics of both plants and animals.
Structure:-
- No cell wall
- Flexible body due to protein rich layer called pellicle.
- 2 flagella present
- Chlorophyll is present (but acquired)
- Habitat:-
- Aquatic
- Mostly in stagnant fresh water
Nutrition:-
- Photosynthetic in presence of light.
- Heterotrophic in absence of light
Reproduction :-
- Mostly asexual
Slime moulds:-
- Saprophytic protists
- Fungus like Protists
Structure:-
- Made up of individual cells that forms an aggregate mass.
- Cell walls are retained even in the mass.
Habitat:-
- Soil , lawn, forest floors.
- Prefer moist decaying habitats.
- Extreme resistant, can survive under adverse conditions
Nutrition:-
- Heterotrophic (saprophytes)
- Feed on bacteria, yeast and fungi
- Amoeba like food ingestion.
Reproduction:-
- mostly asexual using spores.
Protozoa:-
- Animal like protists
- No cell wall
Habitat:- aquatic and moist habitat
Nutrition:-
- heterotrophic
- Can be parasitic or predators.
- Holozoic /animal like nutrition.
Reproduction:-
- Both asexually and sexually
- Protozoans :- groups
- Amoeboid protozoans
- Flagellated Protozoans
- Ciliated protozoans
- Sporozoans
Amoeboid Protozoans:-
- Resemble Amoeba in the presence of pseudopodia
- Some are predators with Amoeba like ingestion of prey.
- Pseudopodia:-
- False feet
- Temporary extension of cytoplasm.
- Helps in locomotion and feedin
- Some are parasites.
- Entamoeba histolytica causes Amebiasis.
Flagellated Protozoans:-
- Protozoans with flagella
- Can be free living or parasitic
- Trypanosoma gambiense - sleeping sickness
Ciliated protozoans:- protozoan with cilia
Cilia:-
- hair like structure arising from surface of a cell
- Multiple short cilia exist that help in locomotion and feeding
- Example:- Paramecium
Sporozoans:-
- Non motile protozoan
- Mostly parasitic
- Reproduce by spore formation
- Example:- Plasmodium causing malaria
Importance of Protists:-
- Source of food for many life forms
- Medical research
- Valuable to industry.
Fungi :- Characteristics
- Eukaryotes:-
- Specific membrane bound cell organelles and distinct nucleus
- Multicellular:-
- Made of multiple cells
- Exception:- yeast
- Heterotrophic:-
- Depend on other for their food
- Prefer moist and warm places to grow
- Found in air, water , soil , on animals and on plants.
- Immobile
- Cell wall present
Fungi structure:-
- Most fungi grow as hyphae.
- Hyphae:- long slender thread like structure
- Interconnected network of hyphae form mycelium
- Cell wall made up of chitin and polysaccharides.
Fungi :-nutrition
- Heterotrophic
- Some are saprophytes
- - feed on. Dead plants and decomposed matter
- Some can be parasites
- Depend on living plants / animals
- Can cause diseases
- Some exist in symbiotic relationship with other organisms.
Symbiosis:- an association between two or more species where one or both mutually benefitted.
Various symbiotic relationship:-
Obligate relationship :-
- Organisms completely depend on each other for survival.
- Example:- insects and flowers; lichen ( fungi + blue green algae)
Facultative relationship:-
- Organisms are not dependent on each other for survival.
- Example:- Buffalo and crow.
Ectosymbiosis:-
- One organisms live on the other.
- Example:- lice in hair.
Endosymbiosis:-
- One organism live inside the other.
- Example:- Bacteria in intestine .
Lichen:-
- Symbiotic relationship between fungi and blue green alga
- Algae:- performs photosynthetic, provides nutrients to fungi
- Fungi - protects algae and give shelter.
Fungi :- classification
Based on the reproductive structures and mode of spore formation, divided into four groups
- phycomycetes
- Ascomycetes
- Basidiomycetes
- Deuteromycetes.
1. Phycomycetes:-
Structure :-
- Mycelium is aseptate.
- Mycelium is coenocytic
- Septate:- Mycelium is divided into smaller uninucleate or multinucleate cells by cross walls.
- Aseptate:-No cross walls/ septum in mycelium
Reproduction:-
Asexual mode:-
- Motile zoospores
- Non motile aplanospores
- Produced endogenously in sporangium
Sexual mode:-
- Fusion of similar gametes (isogamy)
- Fusion of dissimilar gametes (anisogamy)
- Fusion produce zygospores
Phycomycetes example:-
- Rhizobium (bread mould)
- Mucor
- Albugo candida (mustard fungi)
Ascomycetes:-
- Sac fungi
- Structure:-
- Mycelium is septate
- Mycelium is branched
Reproduction:-
- Asexual mode:-
Asexual spore- conidia
- Conidia are produced exogenously by conidiophores
Sexual mode:-
Sexual spores :- Ascospores
- Ascospores are produced endogenously in asci present in fruiting bodies, ascocarps.
- Example:- yeast , Aspergillus, Penicillium, Neurospores.
Basidiomycetes:-
- Club fungi
- Inhibit soil , tree log and plants
- Structure:- mycelium is septate
- Mycelium is branched
Reproduction:-
Asexual mode:-
- No asexual spore formed.
- Fragmentation is common
Sexual mode:-
Sexual spores:- Basidiospores
- Basidiospores are produced endogenously on Basidium is fruiting bodies - Basidiocarps
- Example:- Agaricus ( Mushroom) ,
- Puccini's (rust fungus)
- Puff balls ,
- Bracket fungi
Deuteromycetes:-
- Imperfect fungi
- Mostly decomposers, some are parasites
Structure:- Mycelium is septate and branched.
Reproduction:-
Asexual mode:- Asexual spores - conidia
Sexual mode:- No sexual mode I'd reproduction
Example:- Trichoderma, Alternaria, Colletotrichum falcatum (red rot of sugarcane)
Some common fungi:-
Yeast :- unicellular through some turn multicellular by formation of hyphae.
- Do not need sunlight for growth
- Organic compounds are utilized for energy.
- Used in preparation of bread, beer, wine
- Found in soil, insects, fruits, skin, human toe skin.
Mushroom :-
- Spore bearing fruiting body
- Produced above ground / soil
- Consists of stem cap and spores on underside of cap
Moulds:-
- Multicellular
- Growth in forms of hyphae
- Several drugs are obtained from moulds
- Example:- Antibiotics penicillin
Importance of fungi:-
- Help in decomposition of organic wastes.
- Valuable in plastic industry
- Valuable in obtaining drugs like penicillin.
- Play a role in baking industries.
Fungi - Reproduction
Reproduction by spores:-
- Small particles ejected from reproductive organs which are capable of giving rise to new organisms
- Reproduction by mycelial fragmentation:-
- Mycelium seperates into pieces which inturn forms a new one.
By budding:-
- New organism develops and remains attached to parent organism, once grown get detached
Sexual reproduction:-
- Sexual reproduction often occurs in response to adverse environment conditions
- No male / female fungi
- Two mating types :-( + and -)
Homothallic :- when two mating types are present on same mycelium
Heterothallic:- when two compatible mating totes are present on different mycelium.
Haploid:- cell with a single complete set of chromosome.
Diploid:- cell with two complete sets of chromosomes
Fungi :- sexual cycle :
- Three step process.
- Plasmogamy :-
- Cytoplasm marriage
- Cytoplasm of two haploid cells fused
Two haploid nuclei in one cell - dukaryotic
Karyogamy:-
- Nucleus marriage
- two haploid nuclei fuse
1 diploid zygote formed - process called fertilization
Meiosis :- 4 haploid spores produce.
2 with "+" mating type
2 with "-" mating type.
Are viruses living or non living?
Non living :-
- No components of cell
- No cell membrane
- Inert
- No metabolism
- No reproduction on its own
Living:&
- Inert only outside a living
- Obligate parasites
- Parasite that cannot its life cycle without exploiting a suitable host.
Virus :- structure
- Virus is nucleoprotein
- Virus contain
- - protein
- - genetic material in the form of RNA/DNA
- Protein coat :- capsid ensures protection of nucleic acids.
- Capsid contains helical arrangement of capsomeres.
Plant virus :- single strand of RNA
Animal virus:- Double strand of RNA /DNA
Bacteriophage:- Double strand of DNA
Viral disease:- small pox , influenza, mumps, measles, AIDS, dwarfing in plants, mosaic formation in plants
Viroids:- "viroid means virus like.
- Smaller than virus
- Infectious agents like virus
- Composed of RNA
- NO protein coat.
Differenxe between virus and viroids:-
Virus :-
- Protein coat , capsid present
- Contain single /double stranded RNA/DNA
- smaller than bacteria
Viroids:-
- No protein coat
- Contain free RNA
- even smaller than virus.
Chapter 3 Plant kingdom
Plantae - characteristics
1. Eukaryotes:-
- Specific membrane bound cell organelles and distinct nucleus
2. Multicellular:-
- Made up of multiple cells
3. Autotrophic
- Prepare their own food
4. Immobile
5. Can be aquatic or land plants
6. Cell wall present
Classification system:-
Artificial
Natural
Phylogenetic
Artificial classification system:-
- Basis of classification:-
- External morphological characters
Advantages:-
- Closely related species could be classified
Limitations:-
- equal weightage to vegetative and sexual characteristics.
Natural classification system:-
Basis of classification:-
- External as well as internal characters.
Advantages:-
- Overshadowed limitations of artificial system
- Establishes relationship between organisms.
Limitations:-
- closely related organisms can differ in important properties.
Phylogenetic classification system:-
Basis of classification-
- Evolutionary relationships between organisms
- Similar and dissimilar features of organisms
- Depends on information from cytotaxonomy , chemotaxonomy and numerical taxonomy.
Advantage:-
- tell about evolutionary history of organisms.
Limitation:-
- Closely related organisms can differ in important properties.
Sources which help in classification:-
- Numerical taxonomy
- Cytotaxonomy
- Chemotaxonomy
Numerical taxonomy:-
- Mathematical method of classification based on observable characters.
- Number are assigned to each character.
Cytotaxonomy:-
- Classification using comparative studies of chromosomes
Chemotaxonomy:-
- Classification based on chemical composition of plants.
Bases of sub-classification of plantae:-
- Differentiation of plant body
- Ability to bear seeds
- Type of seeds (naked/covered)
Plantae :- classification
- Thallophyta
- Bryophyta
- Pteridophyta
- Phanerogams
- - Gymnosperms
- -Angiosperms
Thallophyta
- No body differentiation
- Prefer aquatic habitat
- Example:- free algae
- Hidden reproductive system
- Plants with hidden reproductive system are called cryptogammae.
Algae:- characteristics
- Autotrophic
- Habitat:- mostly aquatic (fresh water/ marine)
- Found in moist soil/ wood
- Can be unicellular /colonial/filamentous
- Example:- volvox (colonial)
- Chlamydomonas (unicellular)
- Ulothrix (filamentous)
- Spirogyra (filamentous)
- Ulva (sea lattuce)
- Cladophora (river weed) (branched filamentous)
Algae reproduction:-
- Asexual reproduction
- Sexual reproduction
Asexual reproduction:-
Fragmentation:- parents breaks into multiple pieces on maturity, each of which give rise to a new individual. Example:- Spirogyra.
Multiple fission:-
- Many new individuals are formed.
- Nucleus divide repeatedly .
- Takes place during unfavourable conditions.
- (Cyst formation takes place)
- Example:- chlamydomonas
Spore formation:-
- Production of asexual spores.
- Reproductive parts - zoosporangium
- Asexual spores- zoospores.
Algae :- sexual reproduction
- Fusion of two gametes
Types :-
Isogamous:-
- Both gametes are similar in size. Example:- Spirogyra and chlamydomonas.
Anisogamous:-
- Gametes are dissimilar in size.
- Example:- some species of chlamydomonas
- Oogamous::
- One gamete in large and non motile while other is small and motile. Example:- volvox.
Algae:- significance
- CO2 fixation on earth
- Increase in oxygen level in atmosphere.
- Important in oxygen level in atmosphere.
- Important source of food
- Some are rich source of protein (chloralla, spirullina)
- Preparation of ice creams and jellies
Photosynthetic pigments:-
Chlorophyll:-
- Colour green
- Predominant in leaves
Types:-
- chlorophyll a,b,c
- Carotenoids:-
- Colour range from yellow to red.
- Pre-dominant in flowers and fruits.
- Carotene- pure carbohydrates
- Xanthophyll - carotenoids with oxygen.
Chlorophyceae - characteristics:-
- Green algae
Autotrophic
Habitat:-
- Primarily freshwater
- Found in soil /tree/bark
- Can be unicellular/colonial/filamentous
Chlorophyceae-structure:-
- Rigid 2 layered cell wall.
- Outer wall - pectin
- Constituent the matrix in which cellular microfibrils are embedded.
- Inner wall- cellulose
- Main load bearing structure
- Chloroplast seen in different shapes in different species
- Chlorophyll a and b present
- Pyrenoid present
- Pyrenoids are storage bodies in chloroplasts which store proteins and starch.
Chlorophyceae - life cycle
- Isogamous /anisogamous /oogamous
- Diploid phase - short lived
- Haploid phase - Dominant
Phaeophyceae - characteristics:-
- Brown Algae
- Marine habitat
- Can be branched /filamentous
- Example:-Laminaria , Fucus, Dictyota
Phaeophyceae- structure:-
- Cell wall made up of cellulose.
- Outer covering of cell wall made of Algin
- Chlorplast seen in different shapes in different species.
- Chlorophyll a , c , carotenoids and xanthophylls present.
- Food is stored in the form of complex carbohydrates like laminaria.
Significant organelles:-
- Plastids
- Vacuoles
- Nucleus
Plant body:-
- Holdfast
- Stipe
- Frond
Phaeophyceae:- life cycle
- Involve succession of haploid and diploid phases.
Rhodophyceae- characteristics
- Red Algae
Habitat :-
aquatic
- - Fresh water/salty water
- - occurs both on surface as well as deep inside water.
- Cell wall made up of cellulose
- - chlorophyll a,d and phycoerythrin present
- Food is store in the form of floridean starch.
Rhodophyceae- life cycle:-
- Similar to brown Algae, except that they do not have flagellated gametes.
Bryophyta:- characteristics -
- Body differentiation exists:-
- Stem like,
- Leaf like structures.
- Plant amphibians
- Mostly found in moist hilly areas
- Specialized vascular tissues absent.
- Significant role in preventing soil erosion.
- Hidden reproductive structure.
- Plant body is called cryptogammae
- Example:- mosses , hornworts, liverworts
Bryophyta - structure:-
- Body differentiation exist.
- Erect with unicellular/multicellular rhizoids.
- No true roots/stems/leaves.
Bryophyta - reproduction
Asexual reproduction:-
- Fragmentation
- Spore formation
- Gammae:-
- - propagating structures in thallose liverworts.
- Green multicellular asexual buds.
Sexual reproduction:-
- Gametophyte
- - produce gametes
- Male gametes - Antherozoids
- Female gametes- egg
- Male sex organs- Antheridium
- Female sex organs- Archegonium.
- Source of food for other animals.
- Prevent soil erosion
- Rock decomposition
- Packing material
Liverworts - characteristics
- Prefer moist and shady habitat.
- Plant body is thalloid.
- -stem like structure
- - tiny leaf like structure
- Typed :- thallose liverworts
- Leafy liverworts
- Example:-
- Marchantia , Riccia , Porella, Anthoceros, Funaria.
Liverworts - Reproduction
Asexual reproduction:-
- Fragmentation of thalli
- Gammae formation
- Gammae :-
- Propagating structures in thallose liverworts
- Green multicellular asexual buds.
Sexual reproduction:-
- Fusion of gametes
- Male and female organs can be on same or different thalli
- Haploid gametophyte is dominant phase of life cycle.
Sporophytes:-
- Diploid stage
- Develop from zygote
- Begins to grow out on top of Archegonium on the female gametophyte plants.
- Consists of three structures
- -Foot :- Anchors to gametophyte
- - seta :- long erect stalk :- transfer water and nutrients from gametophytes
- Capsule:- spores are produced here.
Mosses :- characteristics
- Prefer moist and shady habitat.
- Plant body is simple
- -No seed / flowers
- - simple leaves cover the thin stems
- -root like structures - Rhizoids.
Mosses- uniqueness:-
- Like liverworts, gametophyte is the predominant stage of the life cycle of a moss
- Gametophyte consists of two stages.
- Protonema:-
- Develops from spores
- Green , creeping and branched
- leafy stage:-
- Develop from secondary protonema.
- Upright axis with spirally arranged leaves.
- Mosses :- examples:-
- Funaria, sphagnum, common hair cup moss
Mosses:- reproduction
Asexual reproduction:-
- Fragmentation:- stem / leaf from the moss accidentally broken off can regenerate to form a new plant.
- Budding :- New individual is formed as an outgrowth of parent.
- Daughter seperates away and parent continue to exist.
Sexual reproduction:-
- Resemble leafy liverworts
- Male and female sex organ at apex of shoot.
- Sporophytes in mosses is more elaborate than that in liverworts.
Pteridophytes:-
- Body differentiation exists:-
- True roots , true stems , true leaves
- Specialized vascular tissues present.
- Hidden reproductive system
- -Cryptogammae , - reproduce by spores
- Example:- pteris(fern) marsilea, Selaginella, equisetum
Habitat:-
- first terriestrial plants
- Found in cool, damp , shadty place and some in sandy soil conditions
- Ornamental plants
- Medicinal purpose
- As soil binders
Pteridophyta- structure
- Main plant body- sporophyte
- True root , true stem, true leaves.
- Sporophytes bear sporangia subtended by leaf like appendages called sporophylls.
- Strobili present in some pteridophytes.
- Come like distinct compact structure formed by sporophyll.
Reproduction:-
Asexual reproduction :-
- By spores
- By fragmentation
Sexual reproduction:-
- Sporophyte is main plant body.
Gametophyte:-
- Small, multicellular, mostly photosynthetic thallus.
- Termed as prothallus
Sporophyte:-
- Multicellular, well differentiated, dominant phase
Pteridophyte plant types:-
Homosporous :-
- Sporangia produce similar gametes . Example:- ferns
- Heterospores:-
- Sporangia produce two types of spores
- -megasporea - microspore (example:- Selaginella, salvinia.
Pteridophytes - classification
- Psilopsida
- Sphenosida
- Lycopsida
- Pteropsida
Phanerogams:-
- Body differentiation exists:-
- Roots, stem, leaves
- Specialized vascular tissues present
- Specialized reproductive tissues present
- Seeds are produced.
Phanerogams classification:-
Basis of classification :-
- Types of seeds produced
- Classified into two categories:-
- Gymnosperms, Angiosperms
Gymnosperms:-
- Phanerogams with naked seeds
- Fruitless plants
- Plants are perennial, evergreen and woody
- Needle shaped leaves
- Termed as ' soft wood'
- Example :- Pines , Deodar, Cycads, Red wood tree (tallest )
Gymnosperms :- structure:-
- Main plant body - sporophyte
- Stem- branched (Pine)
- Unbranched (cycus)
Leaves -
- Simple /compound
- Well adapted to withstand extreme conditions
Roots :-
- Generally tap roots
- Coralloid roots
- Mycorrhiza
- Coralloid roots:-
- Short branched irregular roots
- Symbiotic association with cyanobacteria
- Cycas.
Mycorrhiza:-
- Symbiotic association with fungus
- Example:- pinus
Gymnosperm reproduction:-
Heterosporous:-
- Sporangia produces two types of spores
- - microspore and megaspores
- Sporangia are spirally arranged to form compact structure called strobili/cone
- -male strobili and - female strobili
- Male and female gametophyte donor have an independent free living existence
- Male /female cones can be present on same /different trees.
Economic importance:-
- Control soil erosion in forest
- Economic uses:- soap , nail polish, perfume ,food, lumber
Angiosperm:-
- Phanerogams with enclosed seeds
- Bear fruits
- Flowering plants
- Broad leaves
- Termed as "hard wood"
Uses :-
- provide us oxygen to breathe
- Primary source of food for animals.
Economic uses:-
- Lumber , fibers for clothes, medicines
Angiosperms - classification
Basis of classification
- Number of cotyledons inside the enclosed seed.
Cotyledons:-
- Structure or a pre designed plant inside the seed.
- Termed as seed leaves
- Classic into two categories:-
- Dicots and Monocots
- Angiosperms with two cotyledons
- Broad leaves
- Vascular bundles in ring
- Floral parts in multiple of 4 and 5
- Example:- rose, lotus, beans
Monocots:-
- Angiosperms with one cotyledons
- Narrow leaves
- Vascular bundles scattered
- Floral parts in multiple of 3.
Angiosperms - flower structures.
- Stalk :- axis that hold the flowers
- Thalamus :- swollen upper portion of stalk
- Petals:- coloured parts of a flower.
- Attract insects.
- Sepals:- ensure protection
- Stamens:-
- Male reproductive organs
- Male gametes - pollen grains
- carpels :-
- Female reproductive organs.
- Female gametes- ovum /egg
Male reproductive structure:-
Female reproductive structure:-
- Stigma:- sticky surface that receive pollen grains during pollination
- Style :- slender part that join stigma to ovary
- Ovary:- basal swollen part of pistil that contain ovules and eggs.
How does sexual reproduction occur in plants?
- Following steps together complete sexual reproduction in plants:-
- Pollination
- Fertilization
- Seed formation
- Germination
Pollination:-
- Transfer of pollen grains from anther to stigma
- - self pollination
- - cross pollination
- This transfer of pollen grains occur with the help of pollinating agents like wind,water, insects, birds etc.
Fertilization:-
- Unique feature of angiosperms
- Double fertilization
- Fusion of pollen grains and egg
- Zygote is formed
- Fusion of pollen and polar nuclei (sec.nucleus)
- PEN is formed
PEN:-
- Primary endosperm nucleus
- Triploid
- Develops into endosperm
- Provide nourishment to embryo.
Seed formation:-
- Zygote divide repeatedly to form embryo
- Ovule develops a thick coat and forms seed.
- Ovary ripen to form fruit
Germination:-
- Development of seeding from a seed.
Plant life cycle:-
- Haplontic (algae)
- Diplontic (phanerogams)
- Haplo-diplontic(bryophytes and pteridophytes)
Haplontic:-
- Dominant phase - gametophyte
- Sporophytic generation is represented only by zygote.
- Meiosis in zygote results in formation of spores(n)
- Example:- algae like volvox
- Spirogyra and some species of chlamydomonas
Diplontic :-
- Dominant phase - sporophyte
- Gametophyte generation is represented only by gametes. Example:- phanerogams (Gymnosperm and Angiosperms)
Haplo-diplontic :-
- One phase dominant and other intermediate .
- Example :-
- In bryophytes
- Dominant phase- gametophyte (n)
- Intermediate - sporophyte (2n)
- In pteridophytes
- Dominant phase - Sporophyte (2n)
- Intermediate -gametophyte (n)
