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 D - Continuity & Change
Biology SL
Biology SL

Theme D - Continuity & Change

Unlock Genetic Equilibrium Secrets Hardy-Weinberg Guide!

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

Table of content

Hey, Future Biologists! 🤓 Ever wonder how scientists figure out if a population of organisms is evolving or not? Well, it's like playing a genetic game of "spot the difference," and our secret weapon is the Hardy–Weinberg equation! Let's break it down.

The Hardy–Weinberg Equation 🧮

Equation: p² + 2pq + q² = 1

  • : Frequency of homozygous dominant genotype (e.g., AA)
  • : Frequency of homozygous recessive genotype (e.g., aa)
  • 2pq: Frequency of heterozygous genotype (e.g., Aa)

Real-World Example 🌍:

Imagine we have a population of flowers. Some have red petals (AA), some have pink petals (Aa), and others have white petals (aa). We could use the Hardy–Weinberg equation to predict how common each of these flower colors should be if there's no evolution happening!

Conditions for Genetic Equilibrium (Stable Genes 101) 🛑

For a population to be in genetic equilibrium (i.e., not evolving), it needs to meet all these criteria

1️⃣ No Mutation 🚫🧬

  • The genes are stable, no new versions (alleles) popping up.

2️⃣ Random Mating ❤️🐦🐦

  • Organisms can't have a "type." Basically, if you're a blue bird, you shouldn't care if your partner is blue, green, or polka-dotted!

3️⃣ No Immigration or Emigration 🚫✈️

  • Imagine you're in a room full of red gummy bears. Suddenly, a flood of blue gummy bears walks in. That's gonna mess with our "genetic flavor balance," right?

4️⃣ Large Population 🌍

  • The more, the merrier! Small populations can have their allele frequencies changed just by chance, something called 'genetic drift.'

5️⃣ No Natural Selection 🚫🏆

  • Nature doesn't have favorites here. No allele is better than the other; they're all rockstars!

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 🌟

Nail IB's App Icon
IB Resources
Theme D - Continuity & Change
Biology SL
Biology SL

Theme D - Continuity & Change

Unlock Genetic Equilibrium Secrets Hardy-Weinberg Guide!

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

Table of content

Hey, Future Biologists! 🤓 Ever wonder how scientists figure out if a population of organisms is evolving or not? Well, it's like playing a genetic game of "spot the difference," and our secret weapon is the Hardy–Weinberg equation! Let's break it down.

The Hardy–Weinberg Equation 🧮

Equation: p² + 2pq + q² = 1

  • : Frequency of homozygous dominant genotype (e.g., AA)
  • : Frequency of homozygous recessive genotype (e.g., aa)
  • 2pq: Frequency of heterozygous genotype (e.g., Aa)

Real-World Example 🌍:

Imagine we have a population of flowers. Some have red petals (AA), some have pink petals (Aa), and others have white petals (aa). We could use the Hardy–Weinberg equation to predict how common each of these flower colors should be if there's no evolution happening!

Conditions for Genetic Equilibrium (Stable Genes 101) 🛑

For a population to be in genetic equilibrium (i.e., not evolving), it needs to meet all these criteria

1️⃣ No Mutation 🚫🧬

  • The genes are stable, no new versions (alleles) popping up.

2️⃣ Random Mating ❤️🐦🐦

  • Organisms can't have a "type." Basically, if you're a blue bird, you shouldn't care if your partner is blue, green, or polka-dotted!

3️⃣ No Immigration or Emigration 🚫✈️

  • Imagine you're in a room full of red gummy bears. Suddenly, a flood of blue gummy bears walks in. That's gonna mess with our "genetic flavor balance," right?

4️⃣ Large Population 🌍

  • The more, the merrier! Small populations can have their allele frequencies changed just by chance, something called 'genetic drift.'

5️⃣ No Natural Selection 🚫🏆

  • Nature doesn't have favorites here. No allele is better than the other; they're all rockstars!

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 🌟