krit.club logo

The Living World - Biodiversity

Grade 11CBSEBiology

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

•

Biodiversity refers to the number and types of organisms present on Earth. Currently, there are about 1.7−1.81.7 - 1.8 million species known and described.

•

Nomenclature is the system of providing distinct and proper names to organisms so they can be easily identified. This is governed by codes such as ICBNICBN (International Code for Botanical Nomenclature) and ICZNICZN (International Code for Zoological Nomenclature).

•

Binomial Nomenclature, introduced by Carolus Linnaeus, involves two components: the Generic name (GenusGenus) and the Specific epithet (speciesspecies).

•

The rules of nomenclature state that names must be in Latin or latinized, written in italics (or underlined separately when handwritten), with the GenusGenus starting with a capital letter and the speciesspecies with a small letter.

•

Taxonomy is the study of identification, nomenclature, and classification based on characteristics. Systematics includes these aspects along with evolutionary relationships.

•

Taxonomic Hierarchy consists of a series of ranks: Kingdom→Phylum/Division→Class→Order→Family→Genus→SpeciesKingdom \rightarrow Phylum/Division \rightarrow Class \rightarrow Order \rightarrow Family \rightarrow Genus \rightarrow Species.

•

Taxonomic Aids are tools used for identification and classification, such as Herbariums, Botanical Gardens, Museums, Zoological Parks, and Keys (based on contrasting characters in a couplet).

📐Formulae

Scientific Name=Genus+species+(Author′s Name)Scientific\ Name = Genus + species + (Author's\ Name)

Hierarchy:K→P/D→C→O→F→G→SHierarchy: K \rightarrow P/D \rightarrow C \rightarrow O \rightarrow F \rightarrow G \rightarrow S

Species⊂Genus⊂Family⊂Order⊂Class⊂Phylum⊂KingdomSpecies \subset Genus \subset Family \subset Order \subset Class \subset Phylum \subset Kingdom

💡Examples

Problem 1:

Write the correct scientific name for the common Mango tree according to binomial nomenclature rules.

Solution:

Mangifera indicaMangifera\ indica L.

Explanation:

MangiferaMangifera represents the genus name starting with a capital letter, indicaindica is the specific epithet starting with a small letter, and 'L.' denotes the author Linnaeus who first described the species.

Problem 2:

Identify the taxonomic category of Homo sapiensHomo\ sapiens at the 'Family' level.

Solution:

HominidaeHominidae

Explanation:

In the classification of humans, the hierarchy is: Kingdom: AnimaliaKingdom:\ Animalia, Phylum: ChordataPhylum:\ Chordata, Class: MammaliaClass:\ Mammalia, Order: PrimataOrder:\ Primata, Family: HominidaeFamily:\ Hominidae, Genus: HomoGenus:\ Homo, Species: sapiensSpecies:\ sapiens.

Problem 3:

Determine the relationship between the number of common characteristics and the rank in the taxonomic hierarchy.

Solution:

Common Characteristics∝1Taxonomic RankCommon\ Characteristics \propto \frac{1}{Taxonomic\ Rank}

Explanation:

As we go higher from SpeciesSpecies to KingdomKingdom in the taxonomic hierarchy, the number of common characteristics decreases. Organisms in the same species share the most characteristics, while those in the same kingdom share the fewest.

Biodiversity - Revision Notes & Key Diagrams | CBSE Class 11 Biology