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Diversity - Apply binomial nomenclature and describe major divisions of plants and animals

Grade 9CBSE

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

🔑Concepts

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Binomial Nomenclature: A formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms. It was introduced by Carolus Linnaeus.

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Rules of Nomenclature: The first part is the Genus (starts with a capital letter) and the second is the species (starts with a small letter). When printed, it is in italics, e.g., Homo sapiens\textit{Homo sapiens}. When handwritten, the genus and species are underlined separately.

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Plant Kingdom Divisions: Plants are classified based on body differentiation, presence of vascular tissues, and seed formation into: Thallophyta (no distinct body), Bryophyta (amphibians of the plant kingdom), Pteridophyta (vascular tissue present, no seeds), Gymnosperms (naked seeds), and Angiosperms (seeds inside fruits).

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Animal Kingdom Classification: Animals are multicellular eukaryotes without cell walls. They are divided based on cellular/tissue level organization, body symmetry, and presence of a coelom (body cavity).

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Invertebrate Phyla: Includes Porifera (pore-bearers), Coelenterata (hollow body cavity), Platyhelminthes (flatworms), Nematoda (roundworms), Annelida (segmented worms), Arthropoda (jointed legs - largest phylum), Mollusca (soft-bodied), and Echinodermata (spiny-skinned).

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Vertebrata (Phylum Chordata): Characterized by a notochord, dorsal nerve cord, and paired gill pouches. Sub-divided into Pisces, Amphibia, Reptilia, Aves, and Mammalia.

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Warm-blooded vs. Cold-blooded: Animals like Aves and Mammalia maintain a constant body temperature (homeothermic), whereas Pisces, Amphibia, and Reptilia change temperature with the environment (poikilothermic).

📐Formulae

Scientific Name=Genus+species\text{Scientific Name} = \textit{Genus} + \textit{species}

Hierarchy: Kingdom→Phylum/Division→Class→Order→Family→Genus→Species\text{Hierarchy: Kingdom} \rightarrow \text{Phylum/Division} \rightarrow \text{Class} \rightarrow \text{Order} \rightarrow \text{Family} \rightarrow \text{Genus} \rightarrow \text{Species}

Angiosperms={Monocots (single cotyledon)Dicots (two cotyledons)\text{Angiosperms} = \begin{cases} \text{Monocots (single cotyledon)} \\ \text{Dicots (two cotyledons)} \end{cases}

💡Examples

Problem 1:

Write the scientific name of the Mango tree following the rules of binomial nomenclature.

Solution:

Mangifera‾ indica‾\underline{Mangifera} \text{ } \underline{indica}

Explanation:

In this name, Mangifera\textit{Mangifera} represents the Genus (capitalized) and indica\textit{indica} represents the specific epithet (lowercase). Both are underlined separately as per the rules for handwritten names.

Problem 2:

A plant has a well-differentiated body and vascular tissues, but it does not produce seeds. To which division does it belong?

Solution:

Pteridophyta

Explanation:

Pteridophytes are the first terrestrial plants to possess vascular tissues (xylemxylem and phloemphloem) but they reproduce via spores rather than seeds, unlike Gymnosperms or Angiosperms.

Problem 3:

Calculate the number of chambers in the hearts of a Fish, an Amphibian, and a Mammal.

Solution:

Pisces (Fish): 2 chambersAmphibia: 3 chambersMammalia: 4 chambers\begin{array}{l} \text{Pisces (Fish): 2 chambers} \\ \text{Amphibia: 3 chambers} \\ \text{Mammalia: 4 chambers} \end{array}

Explanation:

As we move from Pisces to Mammalia, the circulatory system becomes more complex to support higher metabolic rates and prevent the mixing of oxygenated and deoxygenated blood.