Summary
Selection is a process where certain traits become more common in a population due to environmental or human influences.
- Natural Selection — the greater chance of passing on genes by the best-adapted organisms. Example: Giraffes with longer necks survive better and reproduce more.
- Artificial Selection — humans select organisms with desirable traits to reproduce. Example: Farmers breeding larger tomatoes for better yield.
- Antibiotic Resistance — bacteria evolve to survive antibiotics, making them harder to treat. Example: MRSA is resistant to most antibiotics.
Exam Tips
Key Definitions to Remember
- Natural selection: survival and reproduction of the fittest
- Artificial selection: human-driven breeding for desired traits
- Antibiotic resistance: bacteria surviving antibiotics due to mutations
Common Confusions
- Mixing up natural and artificial selection
- Thinking all bacteria are resistant to antibiotics
Typical Exam Questions
- What is natural selection? It is the process where organisms better adapted to their environment tend to survive and produce more offspring.
- How does artificial selection differ from natural selection? Artificial selection is driven by human choice, while natural selection is driven by environmental factors.
- Why is antibiotic resistance a concern? It makes bacterial infections harder to treat as bacteria evolve to survive antibiotics.
What Examiners Usually Test
- Understanding of natural vs. artificial selection
- Examples of antibiotic resistance
- The process and impact of selective breeding