Biology SL
Biology SL
4
Chapters
553
Notes
Theme A - Unity & Diversity
Theme A - Unity & Diversity
Theme B - Form & Function
Theme B - Form & Function
Theme C - Interaction &  Interdependence
Theme C - Interaction & Interdependence
Theme D - Continuity & Change
Theme D - Continuity & Change
IB Resources
Theme A - Unity & Diversity
Biology SL
Biology SL

Theme A - Unity & Diversity

Unlocking Nature's Secrets Craft The Perfect Dichotomous Key

Word Count Emoji
392 words
Reading Time Emoji
2 mins read
Updated at Emoji
Last edited on 14th Jun 2024

Table of content

What's a dichotomous key? 📌

  • A tool to identify species in a group.
  • "Dichotomy" means dividing into two. So, the key splits your options in half at every step.
  • Think of it as a "Choose Your Own Adventure" book, but for species

How does it work? 📘

  • It has numbered pairs of descriptions.
  • Each pair contrasts two possible features of a species.
  • One description should clearly fit, and the other should not.
  • Depending on the choice, you'll be directed to another numbered pair or reach an identification.

💡 Example: Imagine having two fruits in your hand - an apple and an orange. The key might ask:

  • "Does it have a rough skin?" If yes ➡️ It's an orange. If no ➡️ Go to the next question.
  • "Is it round and red?" If yes ➡️ It's an apple.

Localized keys 🌍

  • Designed for specific areas.
  • Helps identify all species or groups in that area.

Ideas for local keys 🌟

  • Trees in your school or local forest, looking at leaves or bark.
  • Water plants from the nearest pond.
  • Birds that swing by the local bird-feeders.
  • Tiny creatures (invertebrates) living on a specific plant.

🎨 Real-World Fun: Why not create a key for the candies in your snack drawer? "Is it chocolate-based? Does it have a nutty center?"

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IB Resources
Theme A - Unity & Diversity
Biology SL
Biology SL

Theme A - Unity & Diversity

Unlocking Nature's Secrets Craft The Perfect Dichotomous Key

Word Count Emoji
392 words
Reading Time Emoji
2 mins read
Updated at Emoji
Last edited on 14th Jun 2024

Table of content

What's a dichotomous key? 📌

  • A tool to identify species in a group.
  • "Dichotomy" means dividing into two. So, the key splits your options in half at every step.
  • Think of it as a "Choose Your Own Adventure" book, but for species

How does it work? 📘

  • It has numbered pairs of descriptions.
  • Each pair contrasts two possible features of a species.
  • One description should clearly fit, and the other should not.
  • Depending on the choice, you'll be directed to another numbered pair or reach an identification.

💡 Example: Imagine having two fruits in your hand - an apple and an orange. The key might ask:

  • "Does it have a rough skin?" If yes ➡️ It's an orange. If no ➡️ Go to the next question.
  • "Is it round and red?" If yes ➡️ It's an apple.

Localized keys 🌍

  • Designed for specific areas.
  • Helps identify all species or groups in that area.

Ideas for local keys 🌟

  • Trees in your school or local forest, looking at leaves or bark.
  • Water plants from the nearest pond.
  • Birds that swing by the local bird-feeders.
  • Tiny creatures (invertebrates) living on a specific plant.

🎨 Real-World Fun: Why not create a key for the candies in your snack drawer? "Is it chocolate-based? Does it have a nutty center?"

Unlock the Full Content! File Is Locked Emoji

Dive deeper and gain exclusive access to premium files of Biology SL. Subscribe now and get closer to that 45 🌟