Question

question 9 in the context of genetics, the technique of selective breeding:
○ is used primarily to identify genetic variations linked to a particular disease.
○ is used to identify the location of certain genes by referring to those genes whose position is already known.
○ is used to choose organisms for reproduction based on how much of a particular trait they display.
○ is used primarily to study the influence of the degree of heredity on behavior.

Explanation:

1. Analyze the first option: Identifying genetic variations linked to a disease is more related to genetic screening or association studies, not selective breeding.
2. Analyze the second option: Identifying gene location by referring to known - positioned genes is about gene mapping techniques like linkage analysis with known markers, not selective breeding.
3. Analyze the third option: Selective breeding, by definition, involves choosing organisms with desirable traits (based on the amount of a particular trait they show) for reproduction to pass on those traits to the next generation.
4. Analyze the fourth option: Studying the influence of heredity on behavior is related to behavioral genetics research methods like twin studies or adoption studies, not selective breeding.

Answer:

The correct option is: "is used to choose organisms for reproduction based on how much of a particular trait they display."