Lesson Plan

• Define a species as a group of organisms that can interbreed and produce fertile offspring.
• Distinguish between pre‑zygotic and post‑zygotic reproductive isolation mechanisms.
• Explain how Linnaean and phylogenetic classification systems organise species.
• Apply the species concept to real‑world examples and identify reproductive barriers.
• Use a taxonomic hierarchy to place humans within the broader classification.

• Projector and screen
• Whiteboard and markers
• Printed handouts of the taxonomic hierarchy
• Worksheet with species‑boundary case studies
• Phylogenetic tree diagram (Homo, Pan, Gorilla)
• Interactive quiz platform (e.g., Kahoot)

Begin with a quick poll: “What makes a dog a dog?” to spark curiosity about species boundaries. Review students’ prior knowledge of classification ranks from earlier lessons. State that by the end of the lesson they will be able to define a species, explain reproductive isolation, and classify organisms using both Linnaean and phylogenetic approaches.

1. Do‑now (5') – short quiz on definitions of “species” and “classification”.
2. Mini‑lecture (10') – present the species definition, reproductive isolation types, and why classification matters.
3. Group activity (12') – students analyse case studies (dog breeds, humans, wolf‑coyote hybrid) and label the isolation mechanism.
4. Interactive hierarchy build (8') – using the human example, construct the Linnaean ranks on the board.
5. Phylogenetic tree analysis (10') – interpret the suggested tree, discuss common ancestry and evolutionary relationships.
6. Formative check (5') – exit ticket: write a concise definition of a species and give one example of pre‑zygotic isolation.

Summarise the key points: a species is defined by fertile offspring, isolation mechanisms maintain boundaries, and classification systems help organise biodiversity. Collect exit tickets to gauge understanding, and assign a homework task to research a local organism, describing its reproductive isolation strategy.