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Classification and Diversity - The Five Kingdoms

Grade 7IB

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

🔑Concepts

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Taxonomy is the science of naming, describing, and classifying organisms. The hierarchical levels are: Kingdom →\rightarrow Phylum →\rightarrow Class →\rightarrow Order →\rightarrow Family →\rightarrow Genus →\rightarrow Species.

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Binomial Nomenclature is a two-part naming system developed by Carl Linnaeus, consisting of the GenusGenus (capitalized) and the speciesspecies (lowercase), usually written in italics.

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Kingdom Monera (Prokaryotae): Unicellular organisms lacking a true nucleus and membrane-bound organelles. Example: Bacteria.

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Kingdom Protista: Mostly unicellular eukaryotic organisms that do not fit into other kingdoms. Includes AmoebaAmoeba and algae.

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Kingdom Fungi: Multicellular (except yeast) heterotrophs that absorb nutrients via saprotrophic nutrition and have cell walls made of chitin.

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Kingdom Plantae: Multicellular autotrophs that contain chlorophyll and produce food (C6H12O6C_6H_{12}O_6) via photosynthesis.

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Kingdom Animalia: Multicellular heterotrophs that lack cell walls and usually have specialized sensory organs and nervous systems.

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Dichotomous Keys: A tool used by scientists to identify organisms based on a series of choices between two alternative characteristics.

📐Formulae

Photosynthesis: 6CO2+6H2O+light energy→C6H12O6+6O2\text{Photosynthesis: } 6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2

Aerobic Respiration: C6H12O6+6O2→6CO2+6H2O+Energy (ATP)\text{Aerobic Respiration: } C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP)}

Classification Hierarchy: K→P→C→O→F→G→S\text{Classification Hierarchy: } K \rightarrow P \rightarrow C \rightarrow O \rightarrow F \rightarrow G \rightarrow S

💡Examples

Problem 1:

An unknown organism is found to be multicellular, has a cell wall made of cellulose, and contains large amounts of chlorophyll. To which kingdom does it belong?

Solution:

Kingdom Plantae

Explanation:

The presence of a cellulose cell wall and chlorophyll (used for producing C6H12O6C_6H_{12}O_6) are defining characteristics of the Kingdom Plantae.

Problem 2:

What is the correctly formatted scientific name for a human, given the genus is 'Homo' and the species is 'sapiens'?

Solution:

Homo sapiensHomo \space sapiens

Explanation:

According to binomial nomenclature rules, the Genus name must be capitalized, the species name must be lowercase, and the entire name should be italicized or underlined.

Problem 3:

Identify the Kingdom: Unicellular, prokaryotic, can be found in extreme environments or as common decomposers.

Solution:

Kingdom Monera

Explanation:

The term 'prokaryotic' indicates the absence of a nucleus, which is the primary distinguishing feature of Kingdom Monera (Bacteria).