Summary
Classification in biology involves organizing organisms into groups based on shared characteristics.
- Species — a group of organisms that can interbreed and produce fertile offspring.
Example: Humans are a species known as Homo sapiens. - Three Domains — the highest rank in biological classification, based on cell type. Example: Archaea, Bacteria, and Eukarya are the three domains.
- Eukarya — a domain consisting of organisms with eukaryotic cells. Example: Animals, plants, fungi, and protoctists belong to this domain.
- Viruses — acellular microorganisms that rely on host cells for replication. Example: The influenza virus hijacks host cells to reproduce.
Exam Tips
Key Definitions to Remember
- Species
- Three Domains
- Eukarya
- Viruses
Common Confusions
- Confusing species with genus in binomial nomenclature
- Misunderstanding the difference between prokaryotic and eukaryotic cells
Typical Exam Questions
- What is a species? A group of organisms that can interbreed and produce fertile offspring.
- Which domains are prokaryotic? Archaea and Bacteria.
- How do viruses replicate? By hijacking the host cell's replication machinery.
What Examiners Usually Test
- Understanding of the hierarchical classification system
- Differences between the three domains
- Characteristics of the kingdoms within Eukarya