EXPERIMENT 2 Objective. Study of plant specimens and identification with reasons-Bacteria,

  EXPERIMENT 2

Objective. Study of plant specimens and identification with reasons-Bacteria,

Oscillatoria, Spirogyra,Rhizopus, Mushroom /bracket fungi, Yeast, Liver wort, Moss, Fern, Thuja, Pinus, one monocotyledon, one dicotyledon and Lichens.

REQUIREMENTS

Fresh or preserved plant specimens, record file, pencil, eraser, sharpner, ruler, a laboratory guide or practical

PROCEDURE

1 Come prepared in the class for the study of plant specimens.

2.Listen carefully the instructions imparted to you by the teacher and note down the important identifying features told to you.

3.Observe and study the specimens or slide.

4.Draw directly from the specimens or slide showing all the details by taking appropriate scale of magnification.

5.Draw only what is visible to you. Do not sketch the elaborate diagrams from the book. 

6.Take the help of practical guide book to check the correctness of the diagram and labelling its various parts.

7.Label the diagram symmetrically with straight parallel lines.

8.For complete specimens give classification on top of the diagram towards right side.

1. BACTERIA

Classification

Kingdom- Monera

Division- Schizophyta

Order- Eubacteriales

Type-Bacteria

Comments

1. Bacteria are microscopic, unicellular and prokaryotic organisms.

2 Bacteria have different shapes. These are Coccus(spherical), Bacillus (rod shaped), Spirillum (spiral-shaped), Vibrio (comma shaped) and Filamentous.

3.The bacterial cell have prokaryotic organisation i.e.,a distinct nucleus and membrane bound cell organelles are absent. 

4.The hereditary material is in the form of a single circular chromosome, formed of a DNA alone.

5. Some bacteria are pathogenic and cause disease in plants animals and man.

6. Bacteria reproduce by binary fission. Many bacteria also form endospores during unfavorable conditions.

Diagnostic Features

1. Microscopic and unicellular.

2. True nucleus absent.

3. Membrane bound organelles are absent.

4. Hereditary material is in the form of circular DNA.

2. OSCILLATORIA

Classification

Kingdom - Monera

Division Cyanophyta

Class-Cyanophyceae

Genus -Oscillatoria sp.

Comments

1. It occurs in stagnent water, ponds, pools, ditches etc. as bluish green scum on the surface of water.

2.It is a filamentous blue green alga.

3. The filaments of oscillatoria is unbranched and cylindrical. Each filament consists of a trichome made up of a row of cylindrical cells enveloped in a sheath of mucilage. The tip of trichome oscillate like pendulum.

4. Each cell of the filament has prokaryotic organisation. The cytoplasm of the cell is differentiated into a peripheral chromoplasm and a central centroplasm.

5. The chromoplasm contain pigmented thylakoid lamellae and reserve food in the form of cyanophycean granules.

6. The Centro plasm contains nuclear material in the form of circular naked DNA.

7. Reproduction occurs by means of hormogonia formed due to the formation of dead cells.

Diagnostic Features

1. Bluish green in colour.

2.Filaments unbranched and enveloped in a mucilage sheath.

3. Each cell is prokaryotic.

3. SPIROGYRA (Water silk or Pond scum)

Classification

Kingdom - Plantae 

Division- Chlorophyta

Class- Chlorophyceae

Genus- Spirogyra sp.

Comments

1. Spirogyra occurs in fresh water bodies such as ditches, ponds, lakes etc.It is commonly called water silk or pond scum because of slippery touch of its thread like filaments.

2. It is a multicellular, filamentous

alga covered by a green mucilagenous sheath.

3.Each filament consists of cylindrical

cells placed end to end.

4.The cell wall is two layered and is made up of cellulose and pectin.

5. Cytoplasm lies in the periphery of

cell, enclosing a vacuole in the centre.

6. One or more ribbon shaped spirally arranged chloroplasts are present in

the cytoplasm. Each chloroplast bears pyrenoids.

7. Single nucleus is suspended in the

centre of the vacuole by cytoplasmic

strands.

8. It reproduces asexually by fragmen- tation and sexually by conjugation.

Diagnostic Features

1. Unbranched, filamentous body with slimy touch.

2.Ribbon shaped, spiral chloroplast.

3. Nucleus suspended by cytoplasmic strands.

4. RHIZOPUS (Bread mould)

Classification

Kingdom-Fungi

Division-- Eumycophyta

Class - Zygomycetes

Genus-Rhizopus

Species-stolonifer

Comments 

1.It commonly grows on stale bread, decaying vegetables and fruits.

2. Its body is made up of interwoven mass of white cottony threads or hyphae, and is known as mycelium.

3. The hyphae of the mycelium are branched, unseptate and multinucleate (coenocytic hyphae).

4. The horizontally growing hyphae are called stoloniferous hyphae and those penetrating into the substratum are called rhizoidal hyphae. Vertically above rhizoids grow sporangiophores.

5.Each sporangiophore bears a globular sporangium at its tip. The sporangium contains black coloured spores,which give black colour to the mycelium in reproductive phase.

6. Asexual reproduction occurs by spores and sexual reproduction occurs by conjugation.

Diagnostic Features

1.Mycelium is unseptate and multinucleate (coenocytic).

2.Sporangiophores arise in the form of a tufts.

3.Presence of stoloniferous and rhizoidal hyphae.

5. AGARICUS (Mushroom)

Classification

Kingdom -----Fungi

Division-Eumycophyta

Class-Basidiomycetes

Genus Agaricus

Species-compestris

Comments

1.It is a saprophytic fungus that grows in humus rich soils, piles of straw and rotting wooden logs.

2.It has septate mycelium under the substratum. The mycelium produces white or cream coloured umbrella shaped fruit bodies or basidiocarps above the substratum.

3.A basidiocarp consists of a stalk like stipe and a cap like pileus.

4.Pileus is circular, umbrella like and bear a number of vertical plate like structures called gills.

5.The gills bear club shaped basidia on either sides. The basidiospores are placed on the basidia.

Diagnostic Features

1. The fruit body is umbrella shaped.

2. Gills are present on the lower side of the pileus.

6. SACCHAROMYCES (Yeast)

Classification

Kingdom- Fungi

Division- Eumycophyta

Class— Ascomycetes

Genus Saccharomyces sp.

Comments

1.It is commonly found growing in sugary medium such as fruit surfaces, nector, cane juice etc.

2.It is a unicellular but may form a pseudomycelium by repeated buddfor

3.Yeast cell is oval or elliptical in shape with a distinct cell wall made up of chitinous material.

4.The cytoplasm has a large central vacuole with a nucleus on its side. Dark strands over vacuole from the nucleus.

5. Volutin granules and glycogen droplets are present as reserve food in the cytoplasm.

6.Asexual reproduction takes place by budding and sexual reproduction occurs by the formation of ascospores.

Diagnostic Features

1.Unicellular.

2.Presence of nuclear vacuole.

3. Reproduction by budding.

7. RICCIA (Liverwort)

Classification

Kingdom-Plantae

Division-Bryophyta

Class-Hepaticeae

Genus-Riccia sp.

Comments

1. It grows on damp and humid places and commonly found in hilly areas.

2.The plant body is a dorsiventrally flattered and dichotomously branched thallus. It may form a rosette due to repeated dichotomous branching of thallus.

3.The thallus has a midrib on dorsal surface and apical notch with growing point at the apex.

4.Scales and rhizoids are present on the ventral surface. Scales protect the growing apex and retain moisture.

5.Rhizoids are unicellular, colourless and tubular. They help in anchorage and absorption.

6.The thallus represents haploid gametophytic stage. It bears both sex organs-antheridia (male sex organ) and

archegonia (female sex organs).

7. Sporophyte is represented by a capsule, embedded in the thallus. It produces haploid spores.

Diagnostic Features

1. Plant body is a thallus with repeated dichotomous branching.

2. Sex organs and sporophyte embedded in the thallus.

8. MARCHANTIA (Liverwort)

Classification

Kingdom-Plantae

Division-Bryophyta

Class-Hepaticae

Genus-Marchantia sp.

Comments

1.It commonly grows on moist, shady and damp places on hills.

2.The thallus is dorsiventrally flattened and dichotomously branched with notched apex.

3.The thallus bears a median longitudinal groove on dorsal surface and a corresponding ridge on the ventral side.

4.Cup shaped bodies called gemma cups are present on the median groove on dorsal surface of the thallus. The gemma cups contain gemma for vegetative propagation.

5.Multicellular purple coloured scales and unicellular rhizoids are present on the ventral surface of the thallus.

6.Antheridia and archegonia are present on special erect gametophores called antheridiophores and archegoniophores respectively born on separate thallai

7.Sporophyte is produced on the archegoniophore after fertilization. It is differentiated into foot, seta and capsule

Diagnostic Features

1. Plant body is a dorsiventrally flattered and dichotomously branched thallus.

2.Presence of gemma cups.

3.Sex organs are produced on antheridiophores and archegoniophores.

9. FUNARIA HYGROMETRICA (Moss)

Classification

Kingdom Plantae

Division- Bryophyta

Class - Musci

Genus - Funaria

Species -hygrometrica

Comments

1.It commonly grows on moist, shady and damp soils, walls of houses, creoices of rocks.

2.The plant body is gametophyte. It is green, erect and is differentiated into rhizoids, axis (stem) and leaves.

3.Rhizoids are multicellular and branched with oblique septa. 

4.Main axis is erect and bears spirally arranged leaves. Each leaf is sessile with a distinct midrib,

5. The main axis bears antheridia at its apex and is called male shoot. A lateral branch called female shoot bears archegonia at its tip.

6.After fertilization a partially dependent sporophyte develops on the female shoot.

7.The sporophyte is differentiated into foot,seta and capsule. The capsule encloses spore sac that contains spores.

8. The spores germinate into filamentous protonema.

Diagnostic Features

1. Gametophyte is represented by a filamentous protonema and adult leafy gametophyte.

2. Rhizoids branched and obliquely septate.

3. Sporophyte is a partial parasite upon the gametophyte.

10. DRYOPTERIS (Male Fern)

Classification

Kingdom- Plantae

Division- Pteridophyta

Class -Filicinae

Genus -Dryopteris sp.

Comments

1. Dryopteris commonly called male fern, is a perennial land plant. It grows in cool, shady and moist places.

2. The plant body is sporophyte and is differentiated into root, stem (underground rhizome) and pinnately compound leaves (fronds).

3. The young leaves have circinate ptyxis and are covered with hair called ramenta.

4.The mature leaves bear kidney shaped sori. Such leaves are called sporophylls. The sori bear sporangia that contains spores.

5. The spores are haploid which give rise to heart shaped membranous gametophyte called prothallus.

6. The prothallus is monoceious i.e., bears both antheridia and archegonia.

Diagnostic Features

1. Stem is a rhizome.

2. Young leaves have circinate ptyxis and bear ramenta.

3. Leaves pinnate with furcate venation.

11. PINUS ROXBURGHII (Chir)

Classification

Kingdom - Plantae

Division- Spermatophyta

Class Gymnospermae

Genus Pinus

Species - roxburghii

-

Comments

1. It grows in temperate and sub-tropical regions on the slopes of hills.

2. The plant body is sporophyte. It is a evergreen tall tree differentiated into root, stem and leaves.

3. Root have tap root system and often associated with mycorrhizae.

4.Stem is covered with bark and bears two types of branches long shoots and dwarf shoots. The long shoots bear scale leaves and grow indefinitely by apical bud, whereas dwarf branches bear scale leaves

and foliage leaves (called needles) and are of limited growth.

5. The leaves are of two types:

(i) Scale leaves are thin, membranous non- photosynthetic and protective in function.

(i) Foliage leaves are long, acicular, green and photosynthetic in function. Dwarf shoot with its leaves is called spur shoot.

6. Pinus tree is monoecious and bears both male and female cones in spring season.

7.Male cones are borne in clusters on long branches. Each male cone is ovoid, brown in colour, narrow at the base and broad at the apex. A number of membranous microsporophylls are arranged spirally around its axis. Each microsporophyll bear two microsporangia, bearing winged microspores or pollen grains.

8.Female cones are borne singly on the long shoots. Each female cone is cone shaped and bears large and woody megasporophylls. Each megasporophyll bears two ovules on its dorsal surface. The ovules mature into winged seeds.

Diagnostic Features

1. Evergreen, woody, perennial tree.

2.Presence of long shoots and dwarf shoots.

3.Reproductive organs are cones.

4.Seeds are naked.

DICOTYLEDONOUS PLANT

12. BRASSICA CAMPESTRIS (Mustard)

Classification

Kingdom - Plantae

Division -Spermatophyta

Class -Angiospermae

Sub-class -Dicotyledonae

Genus -Brassica

Species -campestris

Comments

1.It is a cultivated annual herb.

2.It has a tap root system.

3.The stem is soft green with distinct nodes and internodes.

4.The leaves are alternate, sessile, simple with lobed margin and reticulate venation.

5.It bears yellow colour flowers for reproduction. Each flower is bisexual and bimerous with cruciform corolla.

6.The fruit is an elongated capsule like with a false septum (replum) called siliqua.

7.The seeds are enclosed within the fruit.

8.The seed contains an embryo with two cotyledons.

Diagnostic Features

1.Tap root system.

2.Leaves with reticulate venation.

3.Bimerous flowers.

4.Seeds are enclosed in fruits.

5. Embryo with two cotyledons.

MONOCOTYLEDONOUS PLANT

13. SPHODELOUS TENEUFOLIUS (Piazi)

Classification

Kingdom - Plantae

Division -Spermatophyta

Class -Angiospermae

Sub-class -Dicotyledonae

Genus -Asphodelus

Species -teneufolius.

Comments

1.It is an annual herbaceous weed found growing along with crops.

2. It bears adventitious root system.

3.The stem is reduced and lies under the soil.

4.Leaves are borne in cluster. Each leaf is cylindrical,hollow and has parallel venation.

5.Floral axis grows out of the soil and bears trimerousflowers.

6.The seeds are produced within the fruits.

7.The seed enclosed an embryo with only one cotyledon.

Diagnostic Features

1. Adventitious root system.

2. Leaves with parallel venation.

3.Flowers trimerous.

4.Seeds enclosed in fruits.

5. Embryo with one cotyledon.

14. LICHENS (A Symbiotic Association)

1. Lichens are composite organisms representing a symbiotic association between a fungus and an alga.

2.Lichens grow on lands, rocks, tree trunks and walls of houses, like dry vegetation.

3.The thallus of a lichen resembles neither alga nor fungus.

4.In a lichen, thallus the algal individual called phycobiont belongs to chlorophyceae or myxophyceae, and the

fungal individual called mycobiont belongs to ascomycetes or Basidiomycetes.

5.Lichens occur in three forms:

(i) Crustose lichens are thin, membranous, found attached to the substratum in the form of a crust.

(ii) Foliose lichens have flat, lobed and leaf like thallus.

(iii) Fruticose lichens have branched and small bushy thallus attached to the substratum by means of a disc.

6.Lichens reproduce vegetatively by fragmentation, asexually by soredia and isidia and sexually by forming

sex organs like those formed in Ascomycetes (sac fungi).

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