Edunes Online EducationClass 11 Biology – Chapter 1: The Living World
Section: 1.1 Diversity in the Living World
Answer:
Biodiversity refers to the number and variety of living organisms present on Earth. It includes diversity at the level of species, genes, and ecosystems. At present, about 1.7–1.8 million species have been identified.
Answer:
Scientific naming is required because:
Common names vary from place to place
One organism may have many local names
Scientific names provide uniformity and universal acceptance
Each organism is identified by one unique name globally
Answer:
Binomial nomenclature is the system of naming organisms using two words:
Generic name
Specific epithet
It was proposed by Carolus Linnaeus.
Answer:
Scientific name of mango: Mangifera indica
Mangifera → Genus
indica → Specific epithet
Answer:
A taxon is a category or unit of classification at any level.
Examples:
Mammals
Wheat
Animals
Dogs
Answer:
Taxonomy is the science of classification that includes:
Characterisation
Identification
Classification
Nomenclature of organisms
Answer:
Scientific names are Latin or Latinised
Genus name starts with a capital letter, species with a small letter
Names are written in italics or underlined when handwritten
(Any two)
Answer:
It indicates the scientist who first described the species.
Example: Mangifera indica Linn.
→ Described by Linnaeus
Answer:
Classification is the process of grouping organisms into convenient categories based on similar and observable characteristics to make their study easier.
Answer:
Systematics is broader than taxonomy because it also includes the evolutionary relationships among organisms, while taxonomy mainly deals with naming and classification.
Answer:
Binomial nomenclature is the system of naming organisms using two words—the genus and the specific epithet. It was introduced by Carolus Linnaeus and is universally accepted.
Rules:
Names are Latin or Latinised
Written in italics (printed) or underlined separately (handwritten)
Genus starts with a capital letter
Species starts with a small letter
Author’s name may be written in abbreviated form
Example: Mangifera indica Linn.
Answer:
Classification is necessary because:
There are millions of organisms
Individual study of each organism is not possible
Grouping helps in easy identification and study
Helps in understanding relationships among organisms
Examples:
Dogs → Mammals → Animals
Wheat → Plants
These categories help us associate common characteristics with organisms.
Answer:
Taxonomy is the scientific study of classification of organisms.
Processes involved:
Characterisation – Studying features of organisms
Identification – Determining the correct organism
Classification – Grouping organisms into taxa
Nomenclature – Assigning scientific names
All these processes together form the basis of taxonomy.
Answer:
Taxa are categories or groups used in classification at different levels.
Examples:
Plants (high-level taxon)
Animals
Mammals
Dogs
Wheat
These taxa are related in a hierarchical manner, where a lower taxon fits into a higher one.
Answer:
Systematics is the branch of biology that deals with the systematic arrangement of organisms and their evolutionary relationships.
Derived from Latin word ‘systema’
Introduced by Linnaeus in Systema Naturae
Earlier: limited to classification
Now includes:
Identification
Nomenclature
Classification
Evolutionary relationships
Use definitions first
Write examples wherever possible
Underline keywords
Follow NCERT terminology strictly