This topic summary covers Knowledge Organiser within Selective Breeding for GCSE Biology. Artificial selection and selective breeding techniques It is section 10 of 11 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 10 of 11
Practice
28 questions
Recall
20 flashcards
Knowledge Organiser
Key Terms
- Selective breeding — humans choose which organisms breed
- Artificial selection — another name for selective breeding
- Inbreeding — breeding between closely related individuals
- Gene pool — all alleles in a breeding population
- Inbreeding depression — reduced fitness from narrow gene pool
- Desired trait — characteristic being selected for
SSBR Steps
- Select — parents with desired trait
- Separate — use them as breeding stock
- Breed — cross them together
- Repeat — select best offspring, breed again
- Over many generations — desired allele frequency increases
Examples
- Wheat — disease resistance, high yield
- Dairy cows — high milk yield
- Dogs — temperament, size, working ability
- Roses — petal size, colour, fragrance
Disadvantages
- Reduces genetic variation (narrows gene pool)
- Inbreeding depression — harmful recessive alleles expressed
- Population vulnerable to disease outbreaks
- Animal welfare issues (e.g., flat-faced dogs)
- No new alleles created — only existing ones selected