BIO NOTES & FACTS

Bryophyta Body differentiation exists:- They have stem-like and leaf-like structure  These are known as plant amphibians because even if they live in soil but they need water to complete their life cycle. water is something which is mandatory for them.  They are mostly found in moist hilly areas the specialized vascular tissue is  absent in them  They play a very significant role in preventing soil erosion They have hidden reproductive system-cryptogamae Example; Mosses, hornworts, liverworts Structure  Here body differentiation exists  They are erect with unicellular/ multicellular rhizoids (Rhizoids: -Hair-like structures from the lower epidermal cells  of bryophytes )  There are no true roots/stem/leaves  Reproduction Asexual reproduction:- They reproduce asexually through fragmentation Spore formation Sexual reproduction:- Gametophyte (plants which produce gametes ) Male gamete - Antherozoid ( They are motile ) Female gamete- Egg (nonmotil

Thallophyta These are the plants with no body differentiation They do have a specific root, stem, leaves so they do not have specific differentiation   They prefer aquatic habitats examples :-green algae In thallophyta they have a hidden reproductive system -cryptogamae Algae They are autotrophic  Habitat :- Mostly aquatic (freshwater/ marine )  , found in most soil/ wood  Structure :- It can be unicellular,colonial, filamanteous  Examples :-volvox ( colonial ), Chlamydomonas (unicellular ), Ulothrix (filamenteous ), Spirogyra ( filamenteous ), Ulva, Cladophora (branched filaments) it is also known as river weed Algae reproduction  Asexual reproduction :- Fragmentation Parent organism will break into new pieces or multiple pieces on maturity, each of which give rise to a new individual. Example :- spirogyra when it  becomes matures it breaks into new pieces and each of these pieces are able to give rise to a new organism altogether. Fission  

P LA NT  KINGDOM Plantae : characterstics Eukaryotes :-specific membrane bound cell organelle & distinct nucleus  Multicellular :- they are  made up of multiple cells  Autotrophic :- prepare their own food  Immobile  They can be aquatic or land plants  Their cell walls are present Classification system  Artificial Natural Phylogenetic Artificial classification system   External morphological characters  Advantages :-closely related species could be classified  Limitations :- Equal weightage to vegetative and sexual characterstics Natural classification system  External as well as internal characters are the basis of classification Advantages :-overshadows limitations of artificial system                        Establishes relationship between organism  Limitations :-closely related organism can differ in important properties  Phylogenetic classification system  Evolutionary relationships between organisms are the basis of classification

Viruses Non living  :-  No components of cell  No cell membrane  Inert  No metabolism No reproduction on its own  Living :- Inert only outside a living host Possess genetic material (DNA/RNA ) They can reproduce / mutate when inside a living host Viruses  Acellular Extremely small "Virus" term is given by ivanowsky Inert outside a host Obligate parasite They are those parasites that cannot complete its life cycle without exploiting a suitable host  Structure : It is a nucleoprotein It contains a protein, genetic material in the form of RNA/DNA It has a protein coat :-capsid ensures protection of nucleic acid Capsid contains helical arrangement of capsomeres  Plant viruses :-  single strand of RNA  Animal viruses :- double strand of RNA/DNA  Bacterial viruses :- Bacteriophages (double strand of DNA ) Diseases :- AIDS , Small pox , Mumps , Influenza, Dwarfing in plants, Mosaic formation in plants  Viroids Viroids mea

Fungi They are eukaryotes having specific membrane bound cell organelles and distinct nucleus They are multicellular made up of multiple cells Exception :-yeast  They are heterotrophic in nature i,e they depend on others They prefer warm & moist places to grow.  They are found in air, water, soil, on animal & plant They are immobile Cells walls are present Structure of fungi Most fungi grow as Hyphae   Hyphae ;-They are long slender, thread like structures. Interconnected network of hyphae forms Mycelium. Cell wall is made up of chitin & polysaccharides. Nutrition :- Heterotrophic Saprophytes - Feed on dead & decomposed matters Some can be parasitic - depending on living plants/ animals Some exist in  symbiotic relationship with  other organism. Fungi: symbiosis  An association between two or more species where one/ both are mutually benefited  Various  symbiotic relationship are :- Obligate relationship - organisms

Dianoflagellates They are protists  with two flagella that's why they are called dianoflagellates  They are neither plant nor animal-like protist  They contain chlorophyll/ carotene/ several groups of Xanthophylls   complex cell covering, cortex is present  Light sensitive organelle, eye spot is found in some of them Erythropsidium :-smallest known eye Habitat :-aquatic (can be fresh water / marine ) Nutrition - photosynthetic, ingestion of prey through Oodinium, Notiluca Reproduction :-fission (asexual ) Sexual mode is seen only in some of them  Red tide They are also known as algal bloom  The coloration of the sea into red is due to rapid multiplication of the red dianoflagellates, gonyaulux, is termed red tide Chemicals released during this processs is extremely harmful for the survival of other aquatic life Euglenoids They share characteristics of both plants and animals  They have a shape changing motion  - metaboly Cell wall