Biology Regents Practice Exam 2025 – Complete Prep Resource

The process that accounts for the unique traits of a Chihuahua puppy compared to its parents is the recombination of genes during sexual reproduction. When a puppy is conceived, genetic material from both parents comes together, resulting in a combination of alleles that can differ from those of the parents. During gamete formation, alleles from each parent undergo recombination—this involves crossing over and independent assortment, which create genetic variation. This genetic shuffling contributes to the unique combination of characteristics expressed in the offspring, including traits such as coat color, size, and temperament.

Other processes, like asexual reproduction or mutations that occur after birth, do not contribute to the genetic diversity inherited from parents. Additionally, while grandparents contribute genes through the parents, the question focuses on the immediate genetic processes during the formation of the puppy itself. Hence, recombination during sexual reproduction is the key process explaining how the puppy's traits can differ from those of its parents.