Diversity In Living World(NCERT)

The Living World: A Summary

1. Wonder of Life

• Life exists in diverse forms and habi­tats: cold moun­tains, forests, oceans, deserts, and hot springs.
• The beau­ty and com­plex­i­ty of life evoke awe, whether it’s the gal­lop­ing of a horse, migrat­ing birds, or the mol­e­c­u­lar activ­i­ties inside cells.
• The ques­tion “What is life?” includes:
• Tech­ni­cal inquiry: Dif­fer­en­ti­at­ing the liv­ing from the non-liv­ing.
• Philo­soph­i­cal inquiry: Under­stand­ing the pur­pose of life.

2. Diversity in the Living World

• The Earth hosts 1.7–1.8 mil­lion species iden­ti­fied so far, but more are dis­cov­ered as explo­ration con­tin­ues.
• Bio­di­ver­si­ty refers to the vari­ety and num­ber of organ­isms present glob­al­ly.

3. Need for Standardized Naming: Nomenclature

• Organ­isms are named sci­en­tif­i­cal­ly to avoid con­fu­sion due to local nam­ing vari­a­tions.
• Nam­ing fol­lows spe­cif­ic rules and prin­ci­ples:
• For plants: Inter­na­tion­al Code for Botan­i­cal Nomen­cla­ture (ICBN).
• For ani­mals: Inter­na­tion­al Code of Zoo­log­i­cal Nomen­cla­ture (ICZN).
• Bino­mi­al Nomen­cla­ture (by Car­o­lus Lin­naeus):
• Each organ­ism is giv­en a two-part Latinized name:
  • Gener­ic name (e.g., Mangifera) starts with a cap­i­tal let­ter.
  • Spe­cif­ic epi­thet (e.g., indi­ca) starts with a low­er­case let­ter.
• Names are ital­i­cized or under­lined when hand­writ­ten.
• The author of the species name is abbre­vi­at­ed, e.g., Mangifera indi­ca Linn.

4. Classification

• Clas­si­fi­ca­tion orga­nizes liv­ing organ­isms into cat­e­gories based on observ­able char­ac­ter­is­tics.
• Cat­e­gories, or taxa, vary in lev­els (e.g., plants, ani­mals, mam­mals, dogs).
• Exam­ple: Dogs → Mam­mals → Ani­mals.

5. Taxonomy and Systematics

• Tax­on­o­my involves:
• Char­ac­ter­i­za­tion, iden­ti­fi­ca­tion, clas­si­fi­ca­tion, and nomen­cla­ture.
• Mod­ern tax­on­o­my con­sid­ers:
• Exter­nal and inter­nal struc­tures.
• Cel­lu­lar struc­tures.
• Devel­op­men­tal process­es.
• Eco­log­i­cal roles.
• Sys­tem­at­ics stud­ies the evo­lu­tion­ary rela­tion­ships between organ­isms.
• Derived from the Latin word sys­tema (sys­tem­at­ic arrange­ment).
• Lin­naeus expand­ed the scope to include iden­ti­fi­ca­tion, nomen­cla­ture, and clas­si­fi­ca­tion.

This sys­temised study of life ensures a com­pre­hen­sive under­stand­ing of its diver­si­ty and rela­tion­ships.

PYQ’S

1. Which of the fol­low­ing is against the rules of ICBN? (a) Hand writ­ten sci­en­tif­ic names should be under­lined. (b) Every species should have a gener­ic name and a spe­cif­ic epi­thet. © Sci­en­tif­ic¹ names are in Latin and should be ital­i­cized. (d) Gener­ic and spe­cif­ic names should be writ­ten start­ing with small let­ters. (Answer:² d) (Year: 2019)
2. Nomen­cla­ture is gov­erned by cer­tain uni­ver­sal rules. Which one of the fol­low­ing is con­trary to the rules of nomen­cla­ture?³ (a) The names are writ­ten in Latin and are ital­i­cised. (b) When writ­ten by hand the names are to be under­lined. © Bio­log­i­cal names can be writ­ten in any lan­guage. (d) The first word in a bio­log­i­cal name rep­re­sents the genus name and the sec­ond is a spe­cif­ic epi­thet.⁴ (Answer: c) (Year: 2016)
3. ICBN stands for (a) Inter­na­tion­al Code of Botan­i­cal Nomen­cla­ture (b) Inter­na­tion­al Con­gress of Bio­log­i­cal Names © Indi­an Code of Botan­i­cal Nomen­cla­ture (d) Indi­an Con­gress of Bio­log­i­cal Names.⁵ (Answer: a) (Year: 2007)
4. Biosys­tem­at­ics aims at (a) the clas­si­fi­ca­tion of organ­isms based on broad mor­pho­log­i­cal char­ac­ters (b) delim­it­ing var­i­ous taxa of organ­isms and estab­lish­ing their rela­tion­ships © the clas­si­fi­ca­tion of organ­isms based on their evo­lu­tion­ary his­to­ry and estab­lish­ing their phy­loge­ny on the total­i­ty of⁶ var­i­ous para­me­ters from all fields of stud­ies (d) iden­ti­fi­ca­tion and arrange­ment of organ­isms on the basis of their cyto­log­i­cal char­ac­ter­is­tics.⁷ (Answer: c) (Year: 2003)
5. The book ‘Gen­era Plan­tarum’ was writ­ten by (a) Engler and Prantl (b) Ben­tham and Hook­er © Bessey (d) Hutchin­son. (Answer: b) (Year: 1999)
6. Lin­naeus is cred­it­ed with (a) bino­mi­al nomen­cla­ture (b) the­o­ry of bio­gen­e­sis © dis­cov­ery of micro­scope (d) dis­cov­ery of blood cir­cu­la­tion. (Answer: a) (Year: 1993)
7. Lin­naeus evolved a sys­tem of nomen­cla­ture called (a) monono­mi­al (b) ver­nac­u­lar © bino­mi­al (d) poly­no­mi­al.(Answer: c) (Year: 1990)
8. The term “New Sys­tem­at­ics” was intro­duced by (a) Ben­tham and Hook­er (b) Lin­naeus © Julian Hux­ley (d) A.P. de Can­dolle. (Answer: c) (Year: 1988)