6.4.1 Classification Systems

• Why is there a need for classification systems in biology?

  To group living organisms
• Arrange the levels of the Linnaean classification system from broadest to most specific.

  1️⃣ Kingdom

  2️⃣ Phylum

  3️⃣ Class

  4️⃣ Order

  5️⃣ Family

  6️⃣ Genus

  7️⃣ Species
• Each level in the Linnaean system narrows down the characteristics shared by organisms
• What is the broadest category in the Linnaean system?

  Kingdom
• Match the level of the Linnaean system with its description:

  Kingdom ↔️ The broadest category

  Phylum ↔️ Divides kingdoms by structure

  Class ↔️ Further divides phyla

  Order ↔️ Groups classes by behavior
• Arrange the levels of the Linnaean system from broadest to most specific.

  1️⃣ Kingdom

  2️⃣ Phylum

  3️⃣ Class

  4️⃣ Order

  5️⃣ Family

  6️⃣ Genus

  7️⃣ Species
• The most specific level in the Linnaean system is the species
• Match the Linnaean levels with their descriptions for humans.

  Kingdom ↔️ Animalia

  Phylum ↔️ Chordata

  Class ↔️ Mammalia

  Order ↔️ Primates
• Which kingdom includes organisms like plants and fungi?

  Plantae
• What is the most specific level in the Linnaean classification of humans?

  Homo sapiens
• What is the basis for the three domains classification system?

  Genetic makeup
• Which domain includes organisms that lack peptidoglycan in their cell walls and often thrive in extreme environments?

  Archaea
• Organisms in the Eukarya domain possess membrane-bound organelles
• Which domain includes organisms with cell walls containing peptidoglycan?

  Bacteria
• Eukarya can be single-celled or multicellular.


  True
• The structure of the three domains system consists of three broad domains: Bacteria, Archaea, and Eukarya
• The three domains system emphasizes the distinct evolutionary paths of major groups.


  True
• Order the purposes of classification systems:

  1️⃣ Identify and name organisms consistently

  2️⃣ Understand their evolutionary relationships

  3️⃣ Organize the natural world in a meaningful way
• The Linnaean system categorizes organisms into a hierarchical structure based on shared physical and genetic traits.
• The most specific level in the Linnaean system is species.

  True
• Match the domain with its key characteristics:

  Bacteria ↔️ Cell walls with peptidoglycan

  Archaea ↔️ Cell walls lack peptidoglycan

  Eukarya ↔️ Possess membrane-bound organelles
• Who proposed the three domains classification system?

  Carl Woese
• Archaea often thrive in extreme environments.


  True
• The three domains system highlights the distinct evolutionary paths of Bacteria and Archaea compared to Eukarya.


  True
• Bacteria are single-celled prokaryotes
• Order the hierarchical levels of the Linnaean system from broadest to most specific.

  1️⃣ Kingdom

  2️⃣ Phylum

  3️⃣ Class

  4️⃣ Order

  5️⃣ Family

  6️⃣ Genus

  7️⃣ Species
• What are classification keys used for?

  Identifying unknown organisms
• Classification keys provide a structured way to identify unknown organisms.


  True
• Match the classification system with its key characteristic:

  Linnaean ↔️ Hierarchical structure

  Three Domains ↔️ Three broad domains

  Phylogenetic ↔️ Branching cladograms
• Phylogenetic classification provides a more nuanced understanding of evolutionary relationships compared to earlier systems.


  True
• Characteristics commonly used to classify organisms include morphology, genetics, biochemistry, and behavior
• Who developed the traditional hierarchical classification system?

  Carl Linnaeus
• Classifying organisms helps scientists understand their evolutionary relationships.

  True
• In the Linnaean system, classes are grouped based on specific anatomical features.
• The Linnaean system categorizes living organisms based on their shared physical and genetic traits
• What is the broadest level in the Linnaean system?

  Kingdom
• The Linnaean system uses 8 levels of classification.

  False
• The genus of humans is Homo
• The Linnaean system categorizes organisms based solely on their genetic traits.

  False
• Bacteria are single-celled prokaryotes with cell walls containing peptidoglycan