Variation & Evolution (AQA GCSE Biology): Flashcards
📚Flashcards
Practise the cards
14 cards from this deck
ShowHide
Practise the cards
14 cards from this deck
What is selective breeding?
What is selective breeding?
When humans choose organisms to breed to produce offspring with desirable characteristics
Example desirable trait in animals
Example desirable trait in animals
More meat
Example desirable traits in plants
Example desirable traits in plants
Disease resistance or big flowers
How long has selective breeding been used?
How long has selective breeding been used?
Many years since domestication
First step in selective breeding
First step in selective breeding
Choose parents with desired characteristics
Second step in selective breeding
Second step in selective breeding
Breed chosen parents together
Third step in selective breeding
Third step in selective breeding
Breed offspring with desired traits together
When does selective breeding process stop?
When does selective breeding process stop?
When all offspring have desired characteristic
Main problem with selective breeding
Main problem with selective breeding
Inbreeding
Why does selective breeding cause inbreeding?
Why does selective breeding cause inbreeding?
Breeding closely related individuals with similar traits
Effect of inbreeding on gene pool
Effect of inbreeding on gene pool
Reduction in number of different alleles
Risk from reduced gene pool
Risk from reduced gene pool
Extinction if environment changes or new disease
Why does reduced gene pool increase extinction risk?
Why does reduced gene pool increase extinction risk?
All have same genetic makeup, fewer with survival advantage
Why do genetic defects increase in selective breeding?
Why do genetic defects increase in selective breeding?
Recessive characteristics more likely to present