Prepare for the Florida Biology EOC Test. Use our comprehensive flashcards and multiple-choice questions, complete with hints and explanations, to get ready for your Biology End-of-Course exam!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.


Which term describes the presence of more than two alleles for one gene?

  1. Codominance

  2. Multiple alleles

  3. Polygenic inheritance

  4. Sex-linked traits

The correct answer is: Multiple alleles

The term that describes the presence of more than two alleles for one gene is "multiple alleles." In genetics, while most genes have only two alleles (one inherited from each parent), some genes can have three or more alternative forms, contributing to a broader variety of phenotypes within a population. A classic example of multiple alleles is the ABO blood type system in humans, where the presence of alleles A, B, and O leads to four possible blood types. Codominance refers to a situation where two alleles are expressed equally in a heterozygous individual, rather than indicating the number of alleles for a gene. Polygenic inheritance involves multiple genes influencing a trait, leading to a continuous range of phenotypes, rather than focusing on a single gene with multiple alleles. Sex-linked traits pertain to genes located on sex chromosomes, which can exhibit patterns of inheritance that are different from other traits but do not address the concept of having multiple alleles for a single gene.