Which term describes a trait that helps an organism survive?

• A. Adaptation
• B. Mutation
• C. Regression
• D. Homology

Answer: (A)

The idea being tested is how features help an organism survive in its environment. An adaptation is a trait that increases an organism’s chances of surviving and reproducing in a given environment. It arises from variation in populations and is shaped by natural selection over generations, so organisms with adaptations are better suited to their surroundings. Examples include a polar bear’s thick fur for insulation or a cactus’s water-saving roots and spines that reduce water loss and deter herbivores.

Mutations are changes in DNA that can create new traits, but the mutation itself isn’t necessarily a trait that helps survival; it’s a source of variation that may or may not become an adaptation. Regression refers to returning to an earlier or less developed state, which isn’t about survival advantages. Homology is about features that are similar due to shared ancestry, not about a trait that improves survival.