Plants kingdom

Plants kingdom

In this chapter we looked at the board classification of living organism under the system proposed by the Whittaker (1969) where in suggested the five kingdom classification viz. Monera, Protista, Fungi, Animalia and Plantae. In this chapter we will detail with further classification with in kingdom plantae popularly known as the plant kingdom.
We must stress here that our understanding of the plant kingdom has change over time . Fungi  and members of the monera and and protista having cell wall has now been excluded from plantae through earlier classification put them in the same kingdom. So the cyanobacteria that are also referred to as blue algae anymore. In this time we will describe the plantae under Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperm.
Let also look out classification with in angiosperms to understand some of the concern that influenced the classification system. The earliest system of classification used only gross superficial morphological characters such as habit color number and shape of leaves etc...they were based mainly on vegetative or on the androecium structure.
 At present phylogenetic classification system based on evolutionary relationship between the various organism are acceptable. This assume that organism are belonging to the same taxa have a common ancestor. We now use information from many other source too help there is no supporting fossil evidence.Numerical taxonomy which is now easily carried out using computers is based on all observable characters.Cytotaxonomy that is based on cytological information like chromosome number, structure, behaviour and chemotaxonomy that uses the chemical constituents of the plants to resolve confusion are also used the chemical constituents of the plants to resolve confusion  are also used by taxonomists.

ALGAE

Algae are chlorophyll bearing simple  thalloid auto trophic and largely aquatic organism. They occur in a variety of other habits ; moist stone soils and wood.Some one of them also occur in association with fungi and animals.
The form of the size of algae is highly variable . The size ranges from the microscopic unicellular forms like chlamydomonas to colonial forms ;like Volvox and to the filamentous forms like Ulothrix and Spirogyra.A few of the marine forms such as kelps form massive plants bodies.
The algae reproduce by the vegetative asexual and sexual methods. Vegetative re production by fragmentation.   The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, Spirogyra and the stoneworts.
No definition of algae is generally accepted. One definition is that algae "have chlorophyll as their primary photosynthetic pigment and lack a sterile covering of cells around their reproductive cells".[4] Some authors exclude all prokaryotes[5] thus do not consider cyanobacteria (blue-green algae) as algae.[6]
Algae constitute a polyphyletic group[5] since they do not include a common ancestor, and although their plastids seem to have a single origin, from cyanobacteria,[2] they were acquired in different ways. Green algae are examples of algae that have primary chloroplasts derived from endosymbiotic cyanobacteria. Diatoms and brown algae are examples of algae with secondary chloroplasts derived from an endosymbiotic red alga.[7]
Algae exhibit a wide range of reproductive strategies, from simple asexual cell division to complex forms of sexual reproduction.[8]
Algae lack the various structures that characterize land plants, such as the phyllids (leaf-like structures) of bryophytes, rhizoids in nonvascular plants, and the roots, leaves, and other organs found in tracheophytes (vascular plants). Most are phototrophic, although some are mixotrophic, deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy, myzotrophy, or phagotrophy.
Some unicellular species of green algae, many golden algae, euglenids, dinoflagellates, and other algae have become heterotrophs (also called colorless or apochlorotic algae), sometimes parasitic, relying entirely on external energy sources and have limited or no photosynthetic apparatus.
[9][10][11] Some other heterotrophic organisms, such as the apicomplexans, are also derived from cells whose ancestors possessed plastids, but are not traditionally considered as algae.
 Algae have photosynthetic machinery ultimately derived from cyanobacteria that produce oxygen as a by-product of photosynthesis, unlike other photosynthetic bacteria such as purple and green sulfur bacteria At present phylogenetic classification system based on evolutionary relationship between the various organism are acceptable. This assume that organism are belonging to the same taxa have a common ancestor. We now use information from many other source too help there is no supporting fossil evidence.Numerical taxonomy which is now easily carried out using computers is based on all observable characters.Cytotaxonomy that is based on cytological information like chromosome number, structure, behaviour and chemotaxonomy that uses the chemical constituents of the plants to resolve confusion are also used the chemical constituents of the plants to resolve confusion  are also used by taxonomists

No definition of algae is generally accepted. One definition is that algae "have chlorophyll as their primary photosynthetic pigment and lack a sterile covering of cells around their reproductive cells".[4] Some authors exclude all prokaryotes[5] thus do not consider cyanobacteria (blue-green algae) as algae

Algae lack the various structures that characterize land plants, such as the phyllids (leaf-like structures) of bryophytes, rhizoids in nonvascular plants, and the roots, leaves, and other organs found in tracheophytes (vascular plants). 

Most are phototrophic, although some are mixotrophic, deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy, myzotrophy, or phagotrophy. Some unicellular species of green algae, many golden algae, euglenids, dinoflagellates, and other algae have become heterotrophs (also called colorless or apochlorotic algae), sometimes parasitic, relying entirely on external energy sources and have limited or no photosynthetic apparatus.

[9][10][11] Some other heterotrophic organisms, such as the apicomplexans, are also derived from cells whose ancestors possessed plastids, but are not traditionally considered as algae. 

Algae have photosynthetic machinery ultimately derived from cyanobacteria that produce oxygen as a by-product of photosynthesis, unlike other photosynthetic bacteria such as purple and green sulfur bacteria

Chlorophyceae

The members of chlorophyceae  are commonly called green algae. The  plant body may be unicellular ,colonial or filamentous. They usually grass green due to the dominance of pigments chlorophyll a and b. The pigments are localised in definite chloroplasts. The chloroplasts mat be discoid, plate like , reticulate , cup shaped , spiral or ribbon shaped in different species.Most of the members have one or more storage bodies called pyrenoids locate in the chloroplasts. Pyrenoid contain protien beside starch. Some algae may store food in the form of  oil droplets . green algaae usually have a rigid cell wall made of an inner layer of cellulose and an outer of pectose.

Vegetative reproduction usually  takes place  by fermentation or by formation  of different types of spores. Asexual repriduuction is by flagellated  zoospores produced in zoosporangia. The sexual reproduction  shows considerable variation  in the type and formation of sex cells and it  may be isigamous, anisogamous  or oogamous . Some commonly found  green algae are:Chlamydomonas , Volvox, Ulothrix, Spirogyra and Chara.

PHAEOPHYCEAE

The members of phaeophyceae or brown algae are found primary  marine habit. They show great variation in size ands form. They range from the simple branched filamentous for to profusely branched forms as represented by kelps which may a reach as height as 100 meters. They posses chlorophyll carotenoids and xanthophyill. They variants in color form olive green to various in size and form shades of brown depended upon the amount of the xanthophyll

pigment.Food is stored as complex carbohydrates which may have been in the form of the laminarin mannitol. The vegetative cells have a cellulosic wall usally covered on the outside by a gelatiounas coating of algin. The plant body is usually attached to the subtractum by a hold fast and as a stalk the stipe and leaf like photosythetic organ the front.Vegetative reproduction take place by fragamentation. Asexual pear shaped have two unequal latterally attached.

sexual reproduction may be isogamous, ansiogamous or oogamous union of gamates may take place in water or with in the oogonium. The gamates are priyoform pear shaped and bear two  laterally attached flagella.The common forms are example.ectocarpus, dictyota, laminaria, sargassum.

Defenition

. Fungi  and members of the monera and and protista having cell wall has now been excluded from plantae through earlier classification put them in the same kingdom. So the cyanobacteria that are also referred to as blue algae anymore. In this time we will describe the plantae under Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperm.This assume that organism are belonging to the same taxa have a common ancestor. We now use information from many other source too help there is no supporting fossil evidence.Numerical taxonomy which is now easily carried out using computers is based on all observable characters.Cytotaxonomy that is based on cytological information like chromosome number, structure, behaviour and chemotaxonomy that uses the chemical constituents of the plants to resolve confusion are also used the chemical constituents of the plants to resolve confusion  are also used by taxonomists

1.Algae are photosynthetic organisms, meaning they use sunlight and chlorophyll to make food.

2.At one time, algae were thought to be plants, but are not because they lack roots, stems and leaves.

3.They live all over the world, from the oceans to the desert, and from hot springs to snow and ice.

4.Many things eat algae, including: fish, sea urchins, worms, snails, sea turtles, seals, crustaceans, and even humans.

5.Seaweed is highly nutritious, delicious, and can be cooked with pasta, put in salads, used in meat dishes, all because of its versatility.

:Examples of algae are seaweed, kelp, and red, brown and green algae.

1 An example of algae in the Pacific Ocean are the giant kelps which growing over 65 yards in length, forming a marine forest.

2 An example of algae is Alginate, made from brown algae, which is used as a thickener in many food products such as ice cream and salad dressings.

3 An example of algae is agar, made from red algae, which is a thickener in food products and an ingredient in time-released drugs, laxatives, shampoos and fertilizers.

Any of several divisions of simple photosynthetic organisms, esp. certain thallophytes, variously one-celled, colonial, or filamentous, containing chlorophyll and other pigments (esp. red and brown), and having no true root, stem, or leaf: algae are found in water or damp places, and include seaweeds and pond scum.

The size ranges from the microscopic unicellular forms like chlamydomonas to colonial forms ;like Volvox and to the filamentous forms like Ulothrix and Spirogyra.A few of the marine forms such as kelps form massive plants bodies.

In this chapter we looked at the board classification of living organism under the system proposed by the Whittaker (1969) where in suggested the five kingdom classification viz. Monera, Protista, Fungi, Animalia and Plantae. In this chapter we will detail with further classification with in kingdom plantae popularly known as the plant kingdom.

We must stress here that our understanding of the plant kingdom has change over time . Fungi  and members of the monera and and protista having cell wall has now been excluded from plantae through earlier classification put them in the same kingdom. So the cyanobacteria that are also referred to as blue algae anymore. In this time we will describe the plantae under Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperm.

Let also look out classification with in angiosperms to understand some of the concern that influenced the classification system. The earliest system of classification used only gross superficial morphological characters such as habit color number and shape of leaves etc...they were based mainly on vegetative or on the androecium structure.
 At present phylogenetic classification system based on evolutionary relationship between the various organism are acceptable. This assume that organism are belonging to the same taxa have a common ancestor. We now use information from many other source too help there is no supporting fossil evidence.Numerical taxonomy which is now easily carried out using computers is based on all observable characters.Cytotaxonomy that is based on cytological information like chromosome number, structure, behaviour and chemotaxonomy that uses the chemical constituents of the plants to resolve confusion are also used the chemical constituents of the plants to resolve confusion  are also used by taxonomists.

aany of several divisions of simple photosynthetic organisms, esp. certain thallophytes, variously one-celled, colonial, or filamentous, containing chlorophyll and other pigments (esp. red and brown), and having no true root, stem, or leaf: algae are found in water or damp places, and include seaweeds and pond scum