Which statement correctly pairs the function of the major armor loci EDA and Pitx1_Pel?

Which statement correctly pairs the function of the major armor loci EDA and Pitx1_Pel?

• A. EDA mainly controls lateral plates; Pitx1_Pel controls pelvic spines.
• B. EDA controls pelvic spines; Pitx1_Pel controls lateral plates.
• C. EDA and Pitx1_Pel control identical traits.
• D. Pitx1_Pel controls gill raker length.

Answer: (A)

This question tests how two major genetic loci control stickleback armor traits: EDA is the driver of lateral plates along the body, while Pitx1_Pel affects the pelvic spines. In freshwater populations, lateral plates are often reduced when EDA activity is lowered, and pelvic spines are reduced due to changes at the Pitx1_Pel locus. Because of this, the pairing that assigns EDA to lateral plates and Pitx1_Pel to pelvic spines is the correct one. The other options mix up which locus influences which trait, or attribute gill raker length to Pitx1_Pel, which isn’t supported by these loci.

This question tests how two major genetic loci control stickleback armor traits: EDA is the driver of lateral plates along the body, while Pitx1_Pel affects the pelvic spines. In freshwater populations, lateral plates are often reduced when EDA activity is lowered, and pelvic spines are reduced due to changes at the Pitx1_Pel locus. Because of this, the pairing that assigns EDA to lateral plates and Pitx1_Pel to pelvic spines is the correct one. The other options mix up which locus influences which trait, or attribute gill raker length to Pitx1_Pel, which isn’t supported by these loci.