`color{blue} ul(mathtt ("GAMETOPHYTE"))` : Gametophyte is the haploid phase in the life cycle of an organism( plant), where sexual reproduction is brought about by the formation of gametes. Such a plant bears the gametes.

`color{blue} ul(mathtt ("SPOROPHYTE"))` : Sporophyte is the diploid phase in the life cycle of organism( plant) , where asexual reproduction leads to the formation of gamete from spores.. Such a plant bears the spores.

`color{blue} ul(mathtt ("ALTERATION OF GENERATION"))` : It is the phenomenon where the two distinct phases of a life cycle of a plant– the diploid sporophytic and the haploid gametophytic alternate with each other. The gametophyte undergoes sexual reproduction
to form the sporophyte. The sporophyte undergoes sexual reproduction to form the gametophyte.

●`color{maroon}"Members"`: Includes all eukaryotic chlorophyll-containing organisms commonly called plants. Kingdom Plantae includes algae, bryophytes, pteridophytes, gymnosperms and angiosperms.

●`color{maroon}"Cell Strucure"`: The plant cells have an eukaryotic structure with prominent
chloroplasts and cell wall mainly made of cellulose. Most are multicellular except some unicellular algae..

●`color{maroon}"Mode of nutrition"`: Most of them are photosynthetic autotrophs. A few members are partially heterotrophic such as the insectivorous plants or parasites.

●`color{maroon}"Life Cycle"`: Life cycle of plants has two distinct phases – the diploid sporophytic and the haploid gametophytic – that alternate with each other. This phenomenon is called alternation of generation.
The lengths of the haploid and diploid phases, and whether these phases are free–living or dependent on others, vary among different groups in plants.

●`color{maroon}"Example"`: Redwood tree, Rose (multicellular), Bladderwort and Venus fly trap (insectivorous plants), Cuscuta (parasite)

●`color{maroon}"Members"`: Includes the higher eukaryotes.basically divided into chordates and non chordates.

●`color{maroon}"Cell Strucure"`: The animal cells are multicellular and their cells lack cell walls.

●`color{maroon}"Mode of nutrition"`: All are heterotrophic (they directly or indirectly depend on plants for food) with holozoic mode of nutrition( ingestion of food).

●`color{maroon}"General Features"`: All the members show these general features.
• They digest their food in an internal cavity and store food reserves as glycogen or fat.
• They follow a definite growth pattern and grow into adults that have a definite shape and size.
• Higher forms show elaborate sensory and neuromotor mechanism.
• Most of them are capable of locomotion.

● `color{maroon}"Mode of Sexual Reproduction"`: The sexual reproduction is by copulation of male and female followed by embryological development.

●`color{maroon}"Example"`: Seahorse, crocodiles, pigeons , elephants etc.

●`color{maroon}"Place in Classification"`: The viruses did not find a place in the five classification since they are not truly ‘living’.

●`color{maroon}"Important History"`: The name virus that means venom or poisonous fluid.
• The name Virus was given by `color{green}"Pasteur"`.
• `color{green}"D.J. Ivanowsky"` (1892) recognised certain microbes as causal organism of the mosaic disease of tobacco. These were found to be smaller than bacteria because they passed through bacteria-proof filters.
•`color{green}"M.W. Beijerinek"` (1898) demonstrated that the extract of the infected plants of tobacco could cause infection in healthy plants and called the fluid as `color{green}"Contagium vivum fluidum"` (infectious living fluid).
• `color{green}"W.M. Stanley"` (1935) showed that viruses could be crystallised and crystals consist largely of proteins.

●`color{maroon}"Cell Strucure"`: The viruses are non-cellular organisms that are characterised by having an inert crystalline structure outside the living cell. They are inert outside their specific host cell.
• In addition to proteins viruses also contain genetic material, that could be either RNA or DNA. No virus contains both RNA and DNA.
• A virus is a nucleoprotein and the genetic material is infectious.
• In general, viruses that infect plants have single stranded RNA and viruses that infect animals have either single or double stranded RNA or double stranded DNA.
• Bacterial viruses or bacteriophages (viruses that infect the bacteria) areusually double stranded DNA viruses.
• The protein coat called capsid made of small subunits called capsomeres, protects the nucleic acid. These capsomeres are arranged in helical or polyhedral geometric forms.

●`color{maroon}"Life Cycle"`: Once they infect a cell they take over the machinery of the host cell to replicate themselves, killing the host.

●`color{maroon}"Mode of nutrition"`: Viruses are obligate parasites.

●`color{maroon}"Disease caused with Example"`: Viruses cause diseases like mumps, small pox, herpes and influenza and AIDS in man. In plants, the symptoms can be
• mosaic formation
• leaf rolling and curling
• yellowing and vein clearing
• dwarfing and stunted growth.

● In 1971 T.O. Diener discovered a new infectious agent that was smaller than viruses and caused potato spindle tuber disease.

● It was found to be a free RNA; it lacked the protein coat that is found in viruses, hence the name viroid.

● The RNA of the viroid was of low molecular weight.

● Lichens are symbiotic associations i.e. mutually useful associations, between algae and fungi.

●The algal component is known as `color{green}"phycobiont"` and fungal component as `color{green}"mycobiont"`, which are autotrophic and heterotrophic, respectively.

● The fungal component may be ascomycota or sometimes basidiomycota. The algal component are single celled forms of green algae or cyanobacteria.

●Algae prepare food for fungi and fungi provide shelter and absorb mineral nutrients and water for its partner.

●Lichens are very `color{green}"good pollution indicators"` – they do not grow in polluted areas.