A Woman with a Defect on One X Chromosome of the Gene

question 18

Multiple Choice

A woman with a defect on one X chromosome of the gene for M cones is married to a man with normal colour vision. Of their daughters, on average:

• A) Half will have defective colour vision and half will have normal colour vision, but be carriers of the defective gene
• B) All will be carriers
• C) Half will be normal and half will be carriers
• D) All will have defective colour vision

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Definitions:

Placebo

A substance with no therapeutic effect, used as a control in testing new drugs, to measure the psychological impact of receiving treatment.

Psychotherapy

A form of treatment for mental health issues, where talking with a trained therapist is used to understand and resolve problematic behaviors, beliefs, feelings, and relationship issues.

Prohibitively Expensive

Describing a cost that is so high it prevents or discourages purchase or usage.

Eclectic

An approach or style that combines elements from various sources or disciplines.