Final answer:
An individual can have two alleles for a given gene, but more than two alleles may exist within a population, as seen in the ABO blood type system with its three alleles. This is a concept in population genetics.
Step-by-step explanation:
The statement that an individual can acquire only one allele per trait, even if multiple alleles are present in the population, is false. In diploid organisms like humans, each individual can have two alleles for a given gene, one inherited from each parent.
However, multiple alleles for a gene can exist within a population. A prime example of this is the ABO blood type system, where three alleles (IA, IB, and i) determine an individual's blood type. Even though an individual can only carry two of these alleles, all three can be present across the population. This concept is essential in the study of population genetics, which explores how allele frequencies change over time within a population.