This is a set of 18 fill-in-the-blank sentence problems to help students study vocabulary words related to Evolution and Natural Selection. The entire set appears on two pages with a word bank. Answer key included. Sentences are simple, varied in style, and teen-friendly: designed to help students connect understanding of terms rather than encourage memorization of definitions. This problem set can be assigned to students for in-class individual or group study, homework, or supplementary practice. Can be assigned in conjunction with other vocabulary practice, before or after the introduction of terms or even to assess student progress in the "Evolution" unit of Biology. Terms covered: biology, genetic variation, organism, population, species, environment, offspring, overproduction, and reproduction.