Biology Taxonomy and Classification

Study Notes

Taxonomy

Definition: Science of naming, describing, and classifying organisms.
Systematics: Study of the evolutionary relationships among species.
Binomial Nomenclature: Naming organisms using a two-part Latin name (genus and species).
Hierarchy: Organisms are categorized into ranks: domain, kingdom, phylum, class, order, family, genus, species.

Classification

Purpose: Organizes biological diversity to simplify study, identification, and communication.
Levels of Classification:
1. Domain: Broadest category; three domains exist (Bacteria, Archaea, Eukarya).
2. Kingdom: Second level; groups organisms based on fundamental characteristics.

Characteristics of Living Things

Cellular Organization: Living organisms are composed of one or more cells.
Metabolism: All life forms acquire and use energy (anabolism and catabolism).
Homeostasis: Ability to maintain stable internal conditions.
Growth and Development: Organisms grow and undergo changes throughout their life cycle.
Reproduction: Ability to produce new individuals, can be asexual or sexual.
Response to Stimuli: Reacts to environmental changes.
Adaptation: Capable of evolving over time through genetic changes.

Types of Classification

Traditional Taxonomy: Based on physical traits and morphology.
Phylogenetic Classification: Based on evolutionary relationships and genetic information.
Linnaean Classification: Uses hierarchical system of naming groups and subgroups.

Kingdom of Living Things

Five Kingdoms: Traditional classification divides life into five main kingdoms:
1. Monera: Prokaryotic organisms (bacteria and archaea).
2. Protista: Mostly unicellular eukaryotic organisms (protozoa, algae).
3. Fungi: Eukaryotic organisms that absorb nutrients through external digestion (mushrooms, yeast).
4. Plantae: Multicellular eukaryotes that perform photosynthesis (plants).
5. Animalia: Multicellular eukaryotes that are primarily heterotrophic (animals).
Current Trends: Some classifications include a three-domain system (Bacteria, Archaea, Eukarya) for a more accurate reflection of evolutionary relationships.

Taxonomy

Definition: The science of naming, describing, and classifying organisms.
Systematics: Study of the evolutionary relationships among species.
Binomial Nomenclature: Uses a two-part Latin name (genus and species) to name organisms.
- For example, Homo sapiens is the scientific name for humans.
Hierarchy: Organizes organisms into a series of nested ranks, from broadest to most specific:
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species

Classification

Purpose: To organize biological diversity, making it easier to study, identify, and communicate about organisms.
Levels of Classification:
- Domain: The broadest category, with three recognized domains:
  - Bacteria
  - Archaea
  - Eukarya
- Kingdom: Groups organisms based on fundamental characteristics. There are traditionally five kingdoms:
  - Monera
  - Protista
  - Fungi
  - Plantae
  - Animalia

Characteristics of Living Things

All living things share these fundamental characteristics:
- Cellular Organization: They're made up of one or more cells.
- Metabolism: They acquire and use energy through anabolism (building up) and catabolism (breaking down) processes.
- Homeostasis: They maintain stable internal conditions despite changes in their environment.
- Growth and Development: They grow and undergo changes throughout their life cycle.
- Reproduction: They produce new individuals, either through asexual or sexual reproduction.
- Response to Stimuli: They react to changes in their environment.
- Adaptation: They evolve over time through genetic changes, allowing them to better suit their environment.

Types of Classification

Traditional Taxonomy: Based on physical traits and morphology.
Phylogenetic Classification: Based on evolutionary relationships and genetic information.
Linnaean Classification: Uses a hierarchical system of naming groups and subgroups, based on shared characteristics.

Kingdoms of Living Things

Five Kingdoms: Traditionally, life is divided into five main kingdoms:
- Monera: Prokaryotic organisms, including bacteria and archaea.
- Protista: Mostly unicellular eukaryotic organisms, like protozoa and algae.
- Fungi: Eukaryotic organisms that absorb nutrients through external digestion, including mushrooms and yeast.
- Plantae: Multicellular eukaryotic organisms that perform photosynthesis, like plants.
- Animalia: Multicellular eukaryotic organisms that obtain nutrients by consuming other organisms (heterotrophic).
Current Trends: Some classifications use a three-domain system (Bacteria, Archaea, Eukarya), reflecting more accurate understanding of evolutionary relationships.

Description

Test your knowledge on the science of taxonomy and the classification of living organisms. This quiz covers concepts such as systematics, binomial nomenclature, and the hierarchy of biological organization. Challenge yourself on the understanding of characteristics that define living things.