This definitions covers Key Definitions within Selective Breeding for GCSE Biology. Artificial selection and selective breeding techniques It is section 5 of 11 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Key Definitions
Selective breeding: The deliberate process by which humans choose parent organisms with desirable characteristics and breed them together over many generations to produce offspring with those characteristics. Also called artificial selection.
Artificial selection: Another name for selective breeding — the selection is carried out by humans rather than by the natural environment.
Inbreeding: The mating of closely related individuals within the same genetic line, which reduces genetic diversity and increases the chance that harmful recessive alleles are expressed.
Gene pool: The total collection of different alleles present within a breeding population. A larger, more diverse gene pool is healthier and more resilient.
Desired trait: The characteristic a breeder is trying to increase in frequency, such as disease resistance, high yield, or large fruit size.
Inbreeding depression: The reduced fitness (poorer health, lower reproductive success, increased disease susceptibility) that results from repeated breeding between closely related individuals, because harmful recessive alleles become homozygous and are expressed.
Practice questions for Selective Breeding
What is selective breeding?
Explain how selective breeding has been used to develop modern wheat varieties with higher yields.
Quick recall flashcards
Give three examples of selective breeding.
1. Dogs — bred for specific traits (speed in greyhounds, herding in border collies, guiding in labradors). 2. Cattle — bred for high milk yield or increased meat production. 3. Wheat — bred for disease resistance, higher yield, and shorter stems (less likely to fall over).
Describe the process of selective breeding.
1. Choose parents that show the desired characteristic. 2. Breed them together. 3. Select offspring that best show the characteristic. 4. Repeat over many generations. Over time the desired trait becomes more common in the population.