GM salmon are bigger and grow faster due to genes from which species?

• A. Atlantic salmon and rainbow trout
• B. Chinook salmon and ocean pout
• C. Sockeye salmon and yellowtail
• D. Coho salmon and halibut

Answer: (B)

GM growth in these salmon comes from combining a growth hormone gene from another species with a regulatory element from a different species to drive its expression. Specifically, the growth hormone gene is taken from Chinook salmon, and the promoter that controls its activity is taken from the ocean pout. The Chinook gene provides the instruction for producing growth hormone, while the ocean pout promoter acts as a switch that keeps that gene turned on in Atlantic salmon, enabling faster, year‑round growth. This combination is what makes the fish grow larger than typical salmon, and it’s why the genes are described as coming from Chinook salmon and ocean pout.