Angiosperms Pollination

Introduction: In this chapter, Angiosperms Pollination, we will discuss in detail. Theophrastus described on Date palm pollination. The role of insects in pollination was described by Kolreuter. Transfer of pollen to stigma is known as Pollination.

Image: Angiosperm pollination

Pollination:

• The transfer of microspore (pollen grain) anther to megasporophyll (stigma) means pollen grain transfer to female via external agents known as pollination. 
• Pollen grains are motionless themselves, which means they require external agents for transference.
• Pollination occurs by water, air, animals, and other gravity factors.
• Types of Pollination: Self and Cross-pollination.

Self Pollination: 

• Pollen grains transfer to genetically related flowers.
• Types of Self Pollination: autogamy and geitonogamy.

A) Autogamy: Pollination occurs in intersexual or anther and stigma are closest. Types of autogamy pollination: homogamy, cleistogamy, and bud.

Image: Homogamy A- Catharanthus, B- Mirabilis jalapa, C- Potato, D, and E- Sunflower

1. Homogamy pollination: This pollination occurs in the same flower. Anthers and stigma come together during maturity, in chasmogamous flowers. Examples: Potato, Mirabilis, etc.
2. Cleistogamy pollination: Anthers and stigma are closed in cleistogamous flowers. Anther dehisces in the closed flower. External agencies are not required for this pollination. Examples: Oxalis, Balsam, etc.
3. Bud pollination: In this pollination, before the opening of buds in the flower, anther and stigma are ripen. Examples: wheat and rice.

B) Geitonogamy: When pollen grains are transferred to another flower on the same plant, e.g., Corn, etc.

Advantage of Self Pollination:

• It protects the maintenance of parental characters.
• Plants do not need to produce a huge amount of pollen grains.
• Removes recessive characters.

Disadvantages of Self Pollination:

• Vitality decreases.
• Immunity decreases.
• Variability reduce.

Cross-Pollination: Transference of pollen grains from one flower to a different flower. For this pollination, external agencies are required. External agencies can be biotic and abiotic.

1. Anemophily: (Wind pollination) With the help of wind, pollen grains transfer to a pistil e.g., Palm, Maize, grasses, etc.

Anemophilous Flowers: 

• These flowers are small in size.
•  flowers do not contain color. 
• Non-essential parts are not present.
• Stamens are more in number.
• Pollen grains are light in weight.
• Pollen grains are dusty.
• Pollen grains are nonsticky.
• Pollen grain formed in huge numbers.
• Approx. 130 million pollen grains formed by Mercurialis annua.
• Stigma is feathery.
• Anemophily is nondirectional.

Image: Anemophily

2. Hydrophily: (Water pollination) With the help of water, pollen grains transfer to a pistil.

• Flowers are small in size.
• Flowers are inconspicuous.
• Nectar is not present.
• Odour is also absent.
• Pollen grains are light in weight.
• Hypohydrophily and epihydrophily are types of hydrophylly.
• Zostera occurs below the water surface i.e., hypohydrophily.
• Vallisneria occurs on the water surface i.e., epihydrophily.

Zostera: 

• It is Seagrass.
• Zostera does not contain exine. 
• Long stigma is present.
• Pollens contains ribbon like structure.
• Pollens are filamentous.
• Contain the same gravity.

Ceratophyllum:

• It is a submerged plant.
• Pollen's structure is rounded.
• pollens do not contain exine.
• Male and female flowers are present on the same plant.
• Stigma is sticky.

Vallisneria:

• Produce a huge number of male flowers.
• It contains two fertile stamens.
• The female flower consists long stalk.

Image: Hydrophily pollination (Vallisneria)

3. Zoophily: (Animal pollination) With the help of animals, pollen grains transfer to a pistil.

• Most birds, bats, and insects play important role in this pollination.
• Bees and butterflies perform pollination activities.

4. Entomophily: (Insect pollination) With the help of insects, pollen grains transfer to a pistil.

• Insects can be wasps, bees, and butterflies for pollination.
• Bees take nectar and pollen grains from flowers.

Entomophilous Flower:

• They are colored.
• Butterflies attract red flowers.
• Corolla, sepals, and bracts contain bright colors.
• Some flower emits an odor.
• The flower contains nectar.
• Some flowers contain edible pollens.
• Pollen grains are covered by pollenkitt.
• Heavy pollen grains are present in these flowers.
• pollination occurs directional.
• Sticky stigma is present.
• Stigma is found inserted.
• Anthers are usually inserted.

Coevolution of Flower and pollinator:

• When two species interact with each other and one species forms modification and the other species forms capacity to adaptability.
• This modification formed in the two species i.e., coevolution.
• Mutation and natural selection help in coevolution.
• Insect pollinated flowers are rich in nectar.

5. Ornithophily: (Birds pollination) With the help of birds, pollen grains transfer to a pistil.

• The birds having long beaks.
• Tropicals are sunbirds and hummingbirds.
• They are less as compared to others.
• Red silk cotton, Bottlebrush, Agave, etc. are pollinated by birds.
• Ornithoflowers: Contains highly nectar, flowers are highly bright-colored, the scent is not present and the shape of corolla is a funnel.

6. Chiropterophily: (Bat pollination) With the help of bats, pollen grains transfer to a pistil. Pollens are transferred a long distance by bats.

Chiropterophilous Flowers:

• They contain dull colors.
• Nectar is present in a high amount.
• Pollens are also in high amounts.
• The Flowers' size is large.

Advantages of Cross-pollination:

• Introduce variations by cross-pollination.
• Increment of adaptability.
• Diseases resistant varieties are formed.
• New varieties are formed.
• Defective characters are removed.
• Yield is also high by cross-pollination.

Disadvantages of Cross-pollination:

• A high amount of pollen grains are waste by this pollination.
• Undesirable characters are formed.
• Good characters can be spoiled.

Self-pollination	Cross-pollination
Transfer of pollen to the stigma of a similar flower.	Transfer of pollen to the stigma of a different flower.
This pollination can occur in closed flowers.	This pollination occurs in only open flowers.
External agencies are not required.	External agencies are necessary.
They produce pure lines.	They formed variations.
Yield can fall with time.	Yield not fall below average.
New varieties not produce.	New varieties are produced.

 Conclusion: Pollination means the transfer of pollens towards the female gametophyte.

This article contains Angiosperms Pollination with images and well explanation.

 

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Angiosperms Life cycle

Angiosperms Life cycle

 Introduction: In this chapter, Angiosperms Life cycle, we will discuss in detail. Angiosperms bear seeds inside fruits. Flowering plants are highly evolved. The first flowering plant was recorded in China and Canada. Most flowering plants are found on earth.

Image: Angiosperm

Characteristic features:

• Angiosperms are found in hills and plains also.
• Microsporophylls and megasporophylls are present.
• Filament and anther are components of microsporophyll.
• Stigma, Style, and ovary are components of megasporophyll.
• The female gametophyte is an embryo sac formed by meiosis.
• Mainly insects help in pollination.
• Eight nucleate state is formed by female gametophyte.
• Egg apparatus, antipodal cells, and two polar nuclei are present in the embryo sac.
• Double fertilization: one male gamete + egg cell→ zygote and second male gamete + diploid secondary nucleus→ Primary endosperm nucleus (3n).
• Triploid primary Endosperm→ form→ the triploid endosperm.
• Endosperm gives nourishment to the embryo.
• Seeds are found in fruit and fruit provide protection in dispersal.
• Xylem and phloems are present.

Image: life-cycle-angiosperm

Structure of Flower:

• The modified shoot is a flower.
• Flowers have different colors, sizes, shapes, and smells.
• A flower developed on a mature plant.
• The flower contains sepals, petals, carpels, and stamens.
• Stamens (androecium) and Carpel (Gynoecium).
• The Accessory organs are sepals and petals.

Image: Flower

See Also: Angiosperms Pollination

Diversity Living World

Stamen: Male organ

• It is the male organ of a flower.
• Stamen contains anther and filament.
• The filament is long and stalk structure in the stamen.
• Anther shows fertility and broader in size.
• When one anther lobe is present, known as monothecous and two-lobe is present, known as dithecous.
• Groove help to the separation of two anther lobes.

Image: Stamen

Structure of Anther:

• It is a fertile portion in the stamen.
•  It is a bilobed structure.
• Every lobe consists of microsporangia.
• Bisporangiate is monothecous stamen.
• Tetrasporangiate is dithecous.
• Four microsporangia parallel to each other.
• Archesporial cells have parietal cells and sporogenous cells.
• Consists of the endothecium, middle layer, and tapetum.

Microsporangium:

• The outer wall and sporogenous tissue are the part of microsporangium.
• The epidermis, endothecium, middle layer, and tapetum are layers of the microsporangial wall.
• Large cells are present in endothecium and tapetum.
• Endothecium consists of fibrous thickenings.
• When middle layers are corrupt then they help in the protection of microspore mother cells.
• Tapetal cells consist of protoplasmic contents.
• Functions of Tapetum: provide nourishment to microspore mother cell and pollen grain, Amoeboid tapetum help in the exine formation of pollen grains, Secretory tapetum increase thickness of exine.

Microsporogenesis: (Formation of microspores or pollen grain)

• Microsporogenesis: microspore mother cell ➡ develop callose ➡ break plasmodesmal connections ➡ mother cell separate ➡ meiosis occurs ➡ produce haploid tetrad ➡ microspores (pollen grains). 

Anther Dehiscence:

• Mature anther ➡ contains two cavities 
• By loss of water ➡ endothecium contract ➡ form concave shape ➡ anther lobe ruptures ➡ Line of dehiscence observed ➡ yellow powdery mass ➡ appears in case of Mustard.

Structure of Pollen Grain:

• Diameter approx. 30-50 μm.
• The starch is found in the cytoplasm.
• Sporoderm is the covering of pollen grain.
• The inner layer is Intine containing pecto-cellulose.
• Sporopollenin found in Exine.
• Strong acid, alkali, enzymes, and high temperature cannot affect the sporopollenin.
• Ektexine and Endexine are components of Exine.
• The foot layer, baculate layer, and tectum are further components of Ektexine.
• Tectum provides in the design of pollen surface.
• Pollenkit consists of yellow, viscous layer, lipid, and carotenoids.
• In dicots, pollen grains contain three germ pores.
• In monocots, pollen grains contain a single germ furrow.
• Pollen grain has the ability to retain germination ability.
• Potato, brinjal, chilly, legumes, etc. have in the month of viability.
• Wheat has less than an hour of viability.
• Liquid nitrogen is used to preserve the pollen grains.
• Pollen causes Asthma and bronchitis-like disorders.
• Pollen contains protein, carbohydrates, and fats, hence they intake in form of tablets and syrups.

Image: Pollen grain

See also: Biological Classification

Protista Protozoan Plasmodium

Microgametotogenesis:

• Male gametophyte start ➡ in the microsporangium➡ young pollen grain embedded➡ into the cytoplasm➡ vacuoles push pollen grain➡ towards the wall➡ protoplast divide mitotically➡ form generative and vegetative cell➡ callose separates the cell➡ generative cell divides➡ into two male gametes (nonmotile).
• Pollen tube carries male gametes.
• Pollen tube secretes hormones.
• Pollen tube takes food.

Image: Microgametogenesis

Female reproductive organ: Pistil

• The female organ is a gynoecium of a flower.
• It can contain monocarpellary, bicarpellary, tricarpellary and multicarpellary.
• When carpels are separate then gynoecium is apocarpous.
• If carpels are not separate means they are fused then gynoecium is syncarpous.
• The pistil consists stigma, style, and ovary.
• Stigma help as a landing purpose for pollens.
• The pistil contains swollen parts i.e ovary.
• In wheat and rice single ovule is present in the ovary.
• Watermelon contains many ovules in the ovary.

Image: Gynoecium

Structure of Ovule:

• Ovule develops into the seed after the fertilization process.
• It is attached to the placenta.
• Funiculus is the stalk of an ovule.
• Orthotropous, anatropous, circinotropous, hemitropous, amphitropous and campylotropous are different types of ovules.
• The mass of parenchymatous cells present in the ovule is called nucellus.
• Micropyle is a narrow pore and present at end of the ovule.
• Chalaza is the place of origin.

Megasporogenesis: development of ovule

• Mound of nucellus ➡ over placenta ➡ integument develop ➡  from base ➡ primary archesporial cell ➡ develop ➡ archesporial cell divides into ➡ primary parietal and primary sporogenous cellm➡ primary sporogenous cell works as ➡ megaspore mother cell➡  then meiosis occurs ➡ form 4 haploid megaspore ➡ megasporogenesis.
•  Only chalazal megaspore performs functions. 

Megagametogenesis: Development of female gametophyte

• Cell enlarges ➡ mitotic division occurs ➡ produce 2 nucleate embryo sac ➡ both nuclei shift ➡ towards ends ➡ divide ➡ 4 nucleate and 8 nucleate ➡ one nucleus in middle ➡ polar nuclei ➡ 3 nuclei at ends ➡ 3 celled apparatus ➡ at the micropylar end ➡ 3 antipodal cells ➡ at chalazal end.

Structure of Embryo sac

•  Oval-shaped structure.
• It consists of 3 micropylar,3 chalazal, and 1 central.
• It consists of eight nuclei.
• Three mitosis and one meiosis occur.
•  Egg apparatus present at micropylar end.
• Antipodal cells are present at the chalazal end.

Image: Embryo sac

Conclusion: Angiosperms are cosmopolitan. Firstly angiosperm fossils were founded in China. They contain mostly bisexual flowers.

This article contains Angiosperms Life cycle with images and well explanation.

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Bryophytes Pteridophytes

 Bryophytes Pteridophytes

  Introduction: In this chapter, Bryophytes Pteridophytes we will discuss in detail. Bryophytes - Bryon means moss, phyton means plant, and Pteridophytes - Pteris means fern, phyton means plant. Stem, leaves, and roots are not present in bryophytes. Instead of roots rhizoids occurs in bryophytes. Pteridophytes contains true stem, leaves, and roots. Pteridophytes are seedless and cryptogamic vascular plants.

Characteristic features of Bryophytes:

• Bryophytes are non vascular plants.
• They are small.
• They have haploid gametophyte.
• They are found in damp and shady areas.
• They grow during the rainy season.
• The maximum height of moss is 60 cm.
• Rhizoids are found.
• Roots are not present.
• Fragmentation, adventitious branches, tubers are helped in vegetative reproduction.
• Sex organs are jacketed.
• Antheridium is male and the female organ is the archegonium.
• Antheridia are rounded and Archegonia are flask-shaped.
• Antheridium is generally motile and Archegonium is non-motile.
• Water is required for male gamete.
• The cuticle is not present on the plant body.
• Mechanical tissue is also absent.
• Sporogonium is dependent on gametophyte.
• The alternation of generation is heteromorphic.

Terrestrial Amphibians:

• Bryophytes are known as terrestrial amphibians.
• Water is required for existence.
• Water is required for the swimming of male gametes.
• Water also protects from transpiration.

Types of Bryophytes: Hepaticopsida, Anthoceropsida, and Bryopsida.

A) Hepaticopsida: They are found in damp soil, trees, ground, and woods, The thallus is flattened, rhizoids are unicellular, parasitic sporogonium, and multicellular scales are present. Examples: Riccia, Sphaerocarpos, Marchantia, Pellia, etc.

 Marchantia - It is small approximately in length is 2-10 cm.

• Photosynthetic filaments are present.
• Smooth walled and tuberculate rhizoids are present.
• Fragmentation, regeneration, and gemmae help in vegetative reproduction.
• Gemmae are biscuit-shaped structures and are borne inside the gemma cups.
• Marchantia having gametophores.
• The Gametophore of the female is archegoniophore and the gametophore of the male is antheridiophore.
• Antheridiophore having eight lobed receptacle.
• Archegoniophore having nine rays receptacle.
• Archegonium having perigynium and a tubular neck.
• The zygote is formed by fertilization.
• Foot, seta, and capsule have parts of Sporogonium.

Marchantia

B) Bryopsida: They have radial symmetry, oblique septa, and branched filament. Sporangium contains columella, assimilatory tissue, and peristome. Examples: Funaria, Sphagnum, Polytrichum, etc.

Funaria - It is small approximately 3-5 cm in height.

• Plant show radial symmetry.
• Rhizoids are multicellular with oblique septa.
• The leaves have midrib.
• Lateral and extraaxillary branching is found.
• The epidermis of the Stem is a single layer.
• Stem and Leaves are gametophytic.
• Vegetative reproduction occurs through Fragmentation.
• The male receptacle contains antheridia and is knobbed.
• The female receptacle contains archegonia and paraphyses.
• Antheridium contains sperm mother cells.
• Archegonium contains a canal cell and a large egg.
• Sporogonium has a foot, curved seta, and asymmetrical capsule.
• The capsule contains nonphotosynthetic columella.
• Filamentous protonema stage is present.

Funaria

See Also: Diversity Living World

Biological Classification

Algae Rhodophyta Phaeophyta Chlorophyta

Economic Importance of Bryophytes: 

• Bryophytes help in the prevention of soil erosion.
• They help in the formation of soil.
• Sphagnum moss is used as a retention of water.
• Peat is used as fuel and manure also.
• Mosses are used as animal food.

PTERIDOPHYTES:

• They are found in shady areas and cool places.
• They are seedless plants.
• Vascular tissues are present.
• Approximately 13000 species are found.
• The plant is differentiated into Leaves, stem, and roots.
• Leaves may be macrophyllous and microphyllous.
• True vessels are absent in Xylem.
• Sieve tube and companion cells are absent in Phloem.
• Spores can be homosporous and heterosporous.
• Heterosporous having microspores and megaspores.
• The gametophyte is independent.
• Antheridia is male and Archegonia is a female sex organ.
• Sperm require water to reach the archegonia.
• Examples: Equisetum, Selaginella, Dryopteris, etc.

Pteridophytes

Economic Importance of Pteridophytes:

• Pteridophytes contain a food source eat by some tribals.
• They have the capability to bind the soil and prevent erosion.
• Also, use for cleaning and polishing metals.
• Azolla shows a symbiotic association.
• Dryopteris show medicinal properties.
• Ferns show the ornamental property.

Classes of Pteridophyta:

1. Psilopsida: 

• Rhizoids are present.
• Aerial stems are photosynthetic.
• Sporangia develop either axially or terminally.
• Cooksonia and Rhynia are primitive forms.

2. Lycopsida:

• The plant is differentiated into stem, leaves, and roots.
• Microphyllous leaves are present.
• A branch is dichotomous.
• Examples: Selaginella, Lycopodium, etc.

3. Sphenopsida:

• A jointed stem is present.
• Multiflagellate spermatozoids are present.
• Example: Equisetum

Selaginella

• Some species form brown balls during the dry season.
• When water is available it turns in green color.
• Leaves are microphyllous.
• Adventitious roots are present.
• Tubers, fragmentation, and bulbils for vegetative reproduction.
• A plant having microspore and megaspore.
• Microsporangia produce haploid microspores.
• Megasporangia produce haploid megaspores.
• Male gametophyte consists prothallial cell and antheridia.
• Female gametophyte consists of endosperm, marginal rhizoids.
• The structure of archegonium is flask-shaped.
• The diploid zygote is formed by fertilization.

Life-cycle-selaginella

Equisetum

• The plant is differentiated into leaves, root, and stem.
• Rhizome and aerial branches are two components of the stem.
• Aerial branches perform the photosynthesis process.
• The xylem contains xylem vessels.
• In arvense species brown aerial branch is fertile.

Fern

• Fern is found in temperate and humid tropics areas.
• It is a seedless plant.
• The plant is differentiated into Leaves, stem, and roots.
• Its maximum height is 20 m.
• It bears adventitious roots.
• It has large leaves called Fronds.
• Leaves can be simple, unipinnate, bipinnate, or tripinnate.
• Open furcate venation is found in the leaves.
• Sporophylls are present.
• Bulbils, rhizome, and adventitious buds help in vegetative reproduction.
• Prothallus having sex organs.
• The Male sex organ is antheridia.
• The Female sex organ is archegonia.
• Sperms are multiflagellate.

Life-cycle-Dryopteris

Conclusion: The plant body of bryophyte is gametophyte and the plant body of pteridophyte is the sporophyte. Pteridophyte contains Vascular tissues.

In this chapter, Bryophytes Pteridophytes above the information is completed in detail with images.

See Also: Protista Protozoan Plasmodium

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Algae Rhodophyta Phaeophyta Chlorophyta

Algae Rhodophyta Phaeophyta Chlorophyta

 INTRODUCTION: In this chapter Algae Rhodophyta Phaeophyta Chlorophyta will discuss in detail. Thallophyta comprises undifferentiated plants. Only algae include in the Thallophyta division. Accessory spores are responsible for asexual reproduction.

Characteristic Features:

• Algae are found in fresh water and marine. Few algae also occur on trees, moist soil, etc.
• It having an undifferentiated body it can be colonial, parenchymatous, or unicellular.
• Vascular tissues are not present.
• Mostly found in aquatic algae do not require water conduction.
• Mechanical tissue is not present.
• Photosynthetic is the mode of nutrition.
• Algae having chlorophyll, xanthophyll, and carotene.
• Isogamy, anisogamy, and oogamy for sexual reproduction.
• Mitospores and meiospores are responsible for asexual reproduction.
• Haplontic, diplontic and diplohaplontic are life cycle of algae.

Image 1: Algae

Rhodophyta:  Red Algae

• Mostly they are marine and autotrophic.
• The plant may be unicellular, parenchymatous, Filamentous.
• Cell wall contains Pectic compounds, Cellulose and Phycocolloids.
• Chlorophyll, Phycoerythrin, Phycocyanin, and Carotenoid photosynthetic pigments are present.
• Calcium carbonate is present all over the walls.
• Chromatophores are present.
• Due to the presence of phycoerythrin algae show red in color.
• Floridian Starch is a food reserve.
• Carpospores, neutral spores, tetraspores take place in asexual reproduction.
• Antheridium is the male sex organ and Carposporophyte is the female sex organ.
• Haploid and diploid is an alternation of generation.

Image 2: Red Algae

Example of Red Algae:

• Polysiphonia: It is a marine alga. Long and Dwarf branches contain a plant. A plant is fixed by Rhizoid and Holdfast. The male sex organ is Antheridia and Carpogonia is the female sex organ. Carposporophyte is developed after fertilization. Carpospore is produced tetrasporophyte.
• Porphyra: It is a marine alga. Neutral spores help in asexual reproduction. The diploid Zygote is formed by sexual reproduction. 
• Gelidium: Attached by a number of rhizoids. It is used in Agar formation.
• Batrachospermum: It is also known as a Frogspawn alga. Monospores help in asexual reproduction. Spermatangia is a male sex organ and Carpogonia is a female sex organ.

Economic Importance of Red Algae:

• Porphyra, Chondrus, etc. algae used as food.
• Agar is used as culture media.
• Carrageenin is used in toothpaste, leather finishing.
• Gloiopeltis used in textiles and paper.
• Corallina helps cure infections.
• Polysiphonia shows anti-bacterial activities.

 Phaeophyta: Brown Algae

• It is Marine algae and is found in colder seas.
• Unicellular forms are not present.
• A plant body is divided into holdfast, stipe, and frond.
• Air vesicles are present and provide buoyancy.
• Cell walls having saccharides, cellulose, and phycocolloids.
• Photosynthetic pigments are Chlorophyll, Fucoxanthin, and Phycocolloid.
• Photosynthetic organelles are present.
• Carbohydrates and lipids are food reserve materials.
• Motile and Nonmotile spores help in Asexual reproduction.
• Isogamy, oogamy, and anisogamy help in sexual reproduction.
• Conduction of food materials by conducting tubes.

Image 3: Brown Algae

Examples of Brown Algae:

• Dictyota: They develop in shallow water. Hairs are present on the surface of the frond. The diploid zygote is formed by fertilization.
• Sargassum: It is used as fodder and manure. Floating and attached forms are found. It shows antimicrobial activities. Holdfast, main axis, and lateral are the parts of a plant. Air bladders are present.
• Fucus: It is the source of fodder and manure. Pneumocysts and conceptacles are present.
• Laminaria: It is large size alga about 1-3 meters. It is used as food, manure, and iodine.
• Ectocarpus: It is a marine alga. Prostate portion and rhizoids help in plant fixation.

Image 4: Life Cycle of Ectocarpus

Economic Importance of Brown Algae: 

• Laminaria, Sargassum, Macrocystis, etc. are used as edible algae.
• Iodine is present in Fucus and Laminaria.
• Potash is found in Macrocystis and Nereocystis.
• Laminaria show antibiotic activities.
• Durvillea show vermifuge properties.

See also: Fungi Phycomycetes Ascomycetes Basidiomycetes

Biological Classification

Protista Protozoan Plasmodium

Chlorophyta: Green Algae

• It is a group of Eukaryotes.
• Mostly found in freshwater.
• They Found or moist soil, trees, and walls.
• The cell wall is made up of cellulose.
• They are unicellular.
• Chloroplast is present.
• Chlorophyll, Carotenoid, and Xanthophylls are photosynthetic pigments.
• Due to the presence of chlorophyll algae show green color.
• Mitospores and meiospores help in asexual reproduction.
• Isogamy, anisogamy, and oogamy help in sexual reproduction.
• The life cycle occurs as Haplontic, diplontic and diplohaplontic.

Image 5: Green Algae

Examples of Green Algae:

1. Chlamydomonas:

• It is a Eukaryotic and biflagellate alga.
• It is found in fresh water and marine.
• The cell wall is made up of Glycoprotein.
• For osmoregulation, contractile vacuoles are present.
• Alga contains a nucleus.
• Zoospores, hypnospores and aplanospores help in asexual reproduction.
• Flagellate spores are in zoospores.
• Hypnospores having thick-walled and Aplanospores having thinly walled.
• Zygotic meiosis forms four haploid zoospores.

2. Ulothrix:

• It is an unbranched.
• Central vacuoles are present.
• Chloroplast is present.
• Fragmentation help in vegetative reproduction.
• Zoospores, hypnospores, aplanospores help in asexual reproduction.
• Biflagellate and tetraflagellate zoospores are motile.
• Hypnospores having thick-walled and aplanospores having thin-walled spores.
• Isogamous helps in sexual reproduction.
• The formation of a zygote is indirect.

3. Spirogyra:

• It is unbranched.
• It is found in freshwater.
• Cells are green.
• Cells capable of division.
• A single nucleus is present.
• Fragmentation help in vegetative reproduction.
• Conjugation help in sexual reproduction.
• Conjugation occurs by scalariform and lateral.
• The formation of the zygote is direct.

4. Chara:

• It is found in freshwater.
• The male sex organ is antheridium and the female sex organ is oogonium.
• Fragmentation help in vegetative reproduction.
• It is used as food for several livings.
• It is used as manure.

5. Volvox:

• It is found in freshwater.
• It contains approx. 500 to 60,000 cells.
• The posterior region cells are large.
• During the swimming, it performs rotation.
• Formation of daughter colonies by asexual reproduction.
• Oogamous help in sexual reproduction.

Economic Importance of Green Algae:

• Ulva, Chlorella, Caulerpa contains minerals, lipids, and vitamin used as a food.
• Caulerpa and Chlorella are used as Antibiotics.

Conclusion: Algae are classified under the plant kingdom and characterized without embryo stage. Algae differentiated the basis of pigments and product storage.

This is the full article on Algae Rhodophyta Phaeophyta Chlorophyta.

 

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Fungi Phycomycetes Ascomycetes Basidiomycetes

Fungi Phycomycetes Ascomycetes Basidiomycetes

INTRODUCTION: In this chapter, Fungi Phycomycetes Ascomycetes Basidiomycetes we will discuss in detail. Fungi is Non-vascular, achlorophyllous, spore-forming.

• Fungi is cosmopolitan.
• Present in water, air, and living organisms.
• Fungi contain chitin.
• Its food reserve is Glycogen.
• Mycology: Study of fungi.
• The mode of nutrition is Heterotrophs.
• Chlorophyll is absent hence not able to prepare their food.
• Saprotrophic fungi obtain food from dead and waste material.

Image 1: Fungi

Fungal Structure: 

• The Body having tubular filaments i.e., Hyphae.
• The filamentous hyphae or mass of hyphae is known as mycelium.
• In yeast mycelium is absent.
• Fungi have vegetative and reproductive phases.

Image 2: Formation of Mycelium

See Also: Protista Photosynthetic Dinoflagellates Euglenoids

Protista Protozoan Plasmodium

Tissue and Cell Structure:  

• When hyphae are held together called Plectenchyma it contains Prosenchyma ( loosely hyphae),  and Pseudoparenchyma ( closely packed hyphae).
• When single nuclei are present condition is monokaryotic.
• When two nuclei are present condition is dikaryotic.
• Chitin is made up of acetyl glucosamine.
• Plastids are absent.
• Mitochondria, Endoplasmic reticulum, ribosomes, microtubules, etc. are present.
• Food reserve is glycogen and oil.

Image 3: Rhizopus

Reproduction: 

1. Sexual reproduction: Involves Karyogamy, plasmogamy, and meiosis.

• Homothallic: when mating occurs between the genetically are similar.
• Heterothallic: when mating occurs between two genetically are different.
• Union of cytoplasm i.e., Plasmogamy, and union of Nuclei i.e., Karyogamy.
• The stage between plasmogamy and karyogamy contains two nuclei (dikaryon).
• Sexual reproduction methods: Plano gametic Copulation: Heterogamous fusion can be Oogamy and anisogamy.
• Gametangial Contact: Male gamete antheridia transfer to female gamete oogonia by fertilization tube.
• Gametangial Copulation: Formation of zygospore.
• Spermatogamy: Male cell carried to the receptive region of the female sex organ.
• Somatogamy: Reproduction occurs by the fusion of two hyphae.

Image 4: Sexual Reproduction in Fungi

2. Vegetative Reproduction:

• Budding: Bud is arising on the parent body. Budding occurs in yeast and many other fungi.
• Fragmentation: By mechanical reason or much other reason parent body breaks up into two or several segments and form a complete organism. Fragmentation occurs in Rhizopus.
• Fission: Yeast divide two or more daughters identical to the parent.

Image 5: Vegetative Reproduction in fungi

3. Asexual Reproduction: 

• Occurs by the formation of spores. They can be motile or non-motile. Sexually produced spores are ascospores, basidiospores and others are asexually produced spores.
• Zoospores: Spores are naked and motile. Flagella help in swimming. Examples: Phytophthora, Albugo, etc.
• Sporangiospores: They are non-flagellate and dispersed by air. Examples: Mucor, Rhizopus, etc.
• Conidia: Spores are non-motile and develop by special hyphae. Example: Penicillium, Aspergillus, etc.
• Chlamydospores: Spores are thick-walled and develop by the accumulation of protoplasm.
• Basidiospores: They are non-motile and develop from basidium.
• Oidia: Produce during excess water and particular salts. Example: Rhizopus etc.
• Ascospores: Spores are non-motile and produce inside asci.

Image 6: Fungal Spores

Fungus Classification:

Image 7: Kingdom Fungi

PHYCOMYCETES: 

• Sexual and Asexual reproduction occurs.
• Phycomycetes divide into two groups i.e., oomycetes and zygomycetes.

1. Oomycetes: Mycelium is multinucleate and aseptate.

• Spore formation occurs by asexual reproduction.
• Biflagellate zoospores, non-flagellate gametes, and smooth flagella are present.
•  Antheridium passes into oogonium by a fertilization tube.
• Examples: the late blight of potato caused by➡ Phytophthora infestans.

2. Zygomycetes: Mycelium is multinucleate and aseptate.

• Mostly saprotrophic, zoospores are absent.
• Non motile Mitospores are present.
• Gametangial copulation for the sexual reproduction.
• Gametes are multinucleate.
• Examples: Soft rot of Apple, strawberry is due to Rhizopus.

Image 8: Zygomycetes

Rhizopus:

• Rhizopus is a black bread mold.
• It is saprotrophic.
• Hyphae are rhizoidal, sporangiophores, stoloniferous, and zygophores.
• Rhizoidal hyphae are branched, sporangiophores are unbranched, stoloniferous are unbranched and zygophores are subaerial.
• Fragmentation for vegetative reproduction.
• Asexual reproduction by sporangiospores, chlamydospores, and oidia.
• Sporangiospores: Sporangiophore develops ➡ sporangium.
• chlamydospores: chlamydospores rise ➡ new mycelium.
• Oidia: They multiply by➡ budding.
• Sexual reproduction: Rhizopus stolonifer is heterothallic. Trisporic acids help in the formation of zygophores. Two gametangia are dissolves and two coenogametes form diploid zygote and zygospore. Germ sporangium develops germ spores.

ASCOMYCETES:

• They are pigmented moulds.
• Septate hyphae are present.
• Cell wall having chitin.
• Budding and fission for asexual reproduction.
• Conidiophores can be branched or unbranched.
• Sexual reproduction by sex cells, gametangial between antheridium and ascogonium.
• Plasmogamy and karyogamy for fertilization.
• Ascospores produce an ascus. The asci form ascocarps. 

Yeast: 

• They are nonmycelial or pseudomycelial.
• Mode of asexual reproduction in yeasts: Fission yeasts, budding yeasts, and halobial yeasts.
• Ascus formation is known in yeasts.
• Yeasts are unicellular and form temporary chains during rapid growth.
• It contains chitin and mannan β glucan.
• The mode of nutrition is saprotrophic.
• Budding and fission occur in asexual reproduction.

Image 9: Life cycle of Yeast

Economic importance of Yeast:

• Saccharomyces cerevisiae is used in baking food.
• Saccharomyces ellipsoidens are used in the brewing industry.
• Yeast is also used in vitaminized food.
• Some yeast is used in the silk industry.

Aspergillus:

• It contaminates bread, jellies, cheese, and laboratory cultures.
• It is rotting the cigars, figs, and many fruits.
• It also causes ear infections.

Penicillium:

• It is commercial antibiotics.
• It spoils citrus food, paper, apple, and other products.
• It helps in the formation of organic acids.

BASIDIOMYCETES:

• It is club fungi.
• Motile cells are not present.
• Primary and Secondary mycelia are present.
• Sex organs do not involve during sexual reproduction.
• Primary mycelium and Secondary mycelium are monokaryotic, dikaryotic respectively.
• Basidium can be septate or aseptate.
• A basidium produces four basidiospores.

Image 10: Basidiomycetes

Mushroom:

• Agaricus campestris is edible.
• The mode of nutrition is saprotrophic.
• Primary mycelium and Secondary mycelium are present but secondary is long-lived.
• Clamp connections show by secondary mycelium.
• Secondary mycelium gives rise mass of hyphae during favorable conditions.
• Stipe is fleshy and its base is swollen.
• Pilus is circular, looking like an umbrella.
• Basidiocarp produces several spores.

Toadstools:

• They are non-edible.
• Toadstools contain poison.
• Having white spores.
• Example: Amanita muscaria etc.

Smuts:

• They produce black spores known as smut spores.
• Spores are exposed in loose smut and spores are not exposed in covered smut.

DEUTEROMYCETES:

• The sexual stage is not known in this class.
• They are unicellular.
• Conidia help for asexual reproduction.
• Examples: Trichoderma, Early blight, Wilts, Arthrobotrys, Red rot, Tikka disease, etc.

Tikka Disease:

• Black and brown spots occur in groundnut leaves.
• Filamentous and septate conidia are present.

Red Rot:

• Midribs of leaf and canes effects by Colletotrichum falcatum, cause red rot in sugarcane.
• It decreases the juice content.

Wilts:

• Banana, Potato, Cotton wilts by Fusarium.
• Chlamydospores, macroconidia, and microconidia spores show by Fusarium oxysporum.

Early Blight:

• Causes occur in Potato and Tomato.
• Causal organism is Alternaria solani.
• Brown spots develop in the leaf.
• Branch and leaf are falls.

Lichens:

• It is the association of fungus and alga.
• The algal partner is a cyanobacterium.
• Lichen grows in alpines, tree bark, roofs, etc.
• Lichen's colors have green, orange, greyish, black, or brown.
• Alga performs photosynthesis activity.
• The fungus has minerals and water that are used by alga for the preparation of food. 

Image 11: Lichens

Importance of Lichens:

• They are used in dyes.
• Ramalina is used in Perfumes.
• Lichen use as colonisers.
• Usnea and Cladonia are used for medicinal purposes.

Mycorrhizae:

• Mutual beneficial of fungus and Root of higher plants.
• Absence of Root hairs and Root cap in these plants.
• Ecto mycorrhizae lie on the Root surface in bulk.
• Endo mycorrhizae lie on the Root surface in little.

Image 12: Mycorrhizae of Pinus

Conclusion:  It is cosmopolitan found in air, water, and soil. Fungi contain fungal cellulose and the food reserve as glycogen.

 This article contains Fungi Phycomycetes Ascomycetes Basidiomycetes with images for better understanding

See Also: Diversity Living World

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