NEET

Def­i­n­i­tion of Decom­po­si­tion Decom­po­si­tion: The process of break­ing down com­plex organ­ic mat­ter into sim­pler inor­gan­ic sub­stances like car­bon diox­ide, water, and nutri­ents. Role of Detri­tus Detri­tus: Dead plant remains (e.g., leaves, bark, flow­ers) and ani­mal remains, includ­ing fecal mat­ter, serve as the raw mate­r­i­al for decom­po­si­tion. Steps in the Decom­po­si­tion Read more…

Ener­gy Source and Pho­to­syn­thet­i­cal­ly Active Radi­a­tion (PAR) The Sun is the pri­ma­ry ener­gy source for all ecosys­tems (except deep-sea hydrother­mal ecosys­tems). Of the total inci­dent solar radi­a­tion, less than 50% is PAR. Plants cap­ture only 2–10% of PAR through pho­to­syn­the­sis, which sus­tains the entire liv­ing world. Ener­gy Flow Char­ac­ter­is­tics Ener­gy flows in a uni­di­rec­tion­al man­ner: From Read more…

Pro­duc­tiv­i­ty in Ecosys­tems Def­i­n­i­tion of Pro­duc­tiv­i­ty Pro­duc­tiv­i­ty: Rate of bio­mass pro­duc­tion in an ecosys­tem, expressed in: Weight: gm⁻² yr⁻¹ Ener­gy: kcal m⁻² yr⁻¹ Pro­duc­tiv­i­ty helps com­pare dif­fer­ent ecosys­tems. Types of Pro­duc­tiv­i­ty Pri­ma­ry Pro­duc­tiv­i­ty: Bio­mass or organ­ic mat­ter pro­duced by plants through pho­to­syn­the­sis. Gross Pri­ma­ry Pro­duc­tiv­i­ty (GPP): Total rate of organ­ic Read more…

Def­i­n­i­tion of Ecosys­tem An ecosys­tem is a func­tion­al unit of nature where liv­ing organ­isms (biot­ic com­po­nents) inter­act among them­selves and with their sur­round­ing phys­i­cal envi­ron­ment (abi­ot­ic com­po­nents). Key Fea­tures of Ecosys­tems Inter­ac­tions: Organ­isms inter­act with each oth­er and with the phys­i­cal envi­ron­ment. These inter­ac­tions form cycles, chains, and webs that Read more…

Ecosys­tem – Struc­ture and Func­tion Intro­duc­tion An ecosys­tem con­sists of biot­ic (liv­ing) and abi­ot­ic (non-liv­ing) com­po­nents. These com­po­nents inter­act, influ­enc­ing each oth­er and their envi­ron­ment. The flow of ener­gy with­in an ecosys­tem inte­grates these com­po­nents into a func­tion­al unit. Phys­i­cal Struc­ture of Ecosys­tems Phys­i­cal Struc­ture: Formed by inter­ac­tions between biot­ic Read more…

Def­i­n­i­tion & Impor­tance of Pre­da­tion: Pre­da­tion is a nat­ur­al process where one organ­ism (preda­tor) hunts and con­sumes anoth­er (prey). It serves as a means of trans­fer­ring ener­gy fixed by autotroph­ic organ­isms (plants) to high­er troph­ic lev­els in the food chain. Pre­da­tion helps reg­u­late the pop­u­la­tion of prey species, ensur­ing ecosys­tem Read more…

Inter­spe­cif­ic Inter­ac­tions: These inter­ac­tions arise from the inter­ac­tion of pop­u­la­tions of two dif­fer­ent species. They can be: Ben­e­fi­cial: One or both species ben­e­fit. Detri­men­tal: One or both species are harmed. Neu­tral: Nei­ther species ben­e­fits nor is harmed. Key Types of Inter­ac­tions (with sym­bols): Mutu­al­ism (+ +): Both species ben­e­fit from Read more…

Repro­duc­tive Fit­ness: Pop­u­la­tions evolve to max­i­mize their repro­duc­tive fit­ness (also called Dar­win­ian fit­ness). High repro­duc­tive fit­ness is asso­ci­at­ed with a high r val­ue (intrin­sic rate of nat­ur­al increase). Repro­duc­tive Strate­gies: Organ­isms adopt strate­gies based on the habi­tat they live in and the selec­tion pres­sures they face. Two major repro­duc­tive pat­terns: Read more…

Resource Lim­i­ta­tion in Nature: Unlim­it­ed resources do not exist in nature for any species. Lim­it­ed resources lead to com­pe­ti­tion among indi­vid­u­als. Only the ‘fittest’ indi­vid­u­als sur­vive and repro­duce (Nat­ur­al Selec­tion). Car­ry­ing Capac­i­ty (K): Car­ry­ing capac­i­ty is the max­i­mum pop­u­la­tion size that a habi­tat can sus­tain with its avail­able resources. Beyond Read more…

Pre­dictable Pat­terns in Pop­u­la­tion Growth Pop­u­la­tion growth can fol­low spe­cif­ic and pre­dictable pat­terns over time. Human pop­u­la­tion growth has raised con­cerns, lead­ing to curios­i­ty about whether ani­mal pop­u­la­tions exhib­it sim­i­lar pat­terns or nat­ur­al restraints. Under­stand­ing these pat­terns can pro­vide insights into con­trol­ling pop­u­la­tion growth. Types of Growth Mod­els Expo­nen­tial Growth: Read more…