In Drosophila, the Genes for Body Coloration and Eye Size

question 146

Multiple Choice

In Drosophila, the genes for body coloration and eye size are on different chromosomes.Normal-colored bodies are dominant to ebony-colored (very dark) bodies, and normal-sized eyes are dominant to eyelessness.Line A is true breeding for normal bodies and normal eyes, whereas line B is true breeding for ebony bodies and eyelessness.From an F₂ cross between lines A and B, 800 flies are scored.How many F₂ flies are expected to have both normal body color and normal eyes?

• A) 3
• B) 50
• C) 150
• D) 450
• E) 600

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Definitions:

Psychological Research

The scientific study of individuals' behaviors, thoughts, and emotions through systematic observation, experimentation, and analysis.

Natural Selection

A process by which species adapt to their environment as individuals with beneficial traits survive and reproduce more successfully than others.

Behaviourism

A theory of learning based on the idea that all behaviors are acquired through conditioning, initiated by interactions with the environment.

John Watson

An American psychologist often cited as one of the founders of behaviorism, emphasizing the importance of observable behaviors over internal phenomena like thoughts and feelings.