biology - CBSE CLASS XI

THE LIVING WORLD

POINTS TO REMEMBER :


Characteristics of Living Organisms : Growth, reproduction, metabolism, cellular organization, consciousness (ability to sense environment), self-replicating and self regulation.

  • Reproduction and growth are NOT defining properties.
  • Metabolism, cellular organization and consciousness are defining properties.

Biodiversity : Term used to refer to the number of varieties of plant and animals on earth.

Nomenclature: standardize the naming of living organism such that a particular organism is known by the name all over the world.

Identification: nomenclature or naming is only possible when the organism is described correctly and we known to what organism the name is attached to.

Need for classification: To organize the vast number of plants and animals into categories that could be named, remembered, studied and understood.

Rules for Nomenclature:

  • Latinized names are used, written in italics
  • First word represents the genus, second word is species name.
  • Printed in italics; if handwritten then underline   separately.
  • First word starts with capital letter while species name written in small letter.

ICBN: International Code of Botanical Nomenclature (for giving scientific name to plants.)

ICZN:  International Code of Zoological Nomenclature (for giving scientific name to animals.)

Taxonomy: Study of principles and procedures of classification.

Binomial Nomenclature: Given by Carolus Linnaeus. Each scientific name has two components - Generic name + Specific epithet.

Systematics:  It deals with classification of organisms based on their diversities and relationships among them. Term was proposed by Carolus Linnaeus who wrote ‘Systema Naturae’.

Taxonomic Hierarchy: Arrangement of various steps (categories or taxa Species → Genus → Family → Order → Class → Phylum (for animals) /Division (for plants) Kingdom→

Species: All the members that can interbreed among themselves and can produce fertile offsprings are the members of same species. This is the bio-logical concept of species proposed by Mayer.

Three Domains of Life: Proposed by Carl Woese in 1990 who also proposed the six kingdom classification for living organisms. The three Do-mains are Archaea, Eubacteria and Eukarya.

Herbarium: Storehouse of dried, pressed and preserved plant specimen on sheets.

Botanical Garden: Collection of living plants for reference.

Taxonomical aids: Zoological Park (Places where wild animals are kept in protected environment.)

  • Keys (Used  for identification of plant and animals on the basis of similarities and dissimilarities.)
  • Fauna: (Index to animal species found in a particular area)
  • Flora (Index to plant species found in a particular area.)
  • Manuals (Provide information for identification of name of species in an area.)
  • Monograph (Contain information on one taxon.)

 

CBSE Biology (Chapter Wise) Class XI ( By Mr. Hare Krushna Giri ) 
Email Id : [email protected]