Natural selection and changing trait frequencies are the focus of this Grade 6 science resource on biological evolution, with students using evidence to explain how populations change over generations.

The worksheet moves beyond simple vocabulary recall by asking students to connect heritable variation, differential reproductive success, environmental pressures, and changes in trait frequencies. Students examine scenarios, identify examples of natural selection, match key vocabulary to definitions, and use evidence to predict which trait becomes more common in a population.

What students practice

• Explain how heritable variation and differential reproductive success can change trait frequencies over generations.
• Identify natural selection driven by environmental pressures.
• Match natural selection vocabulary with accurate definitions.
• Use evidence from scenarios to predict changes in trait frequency.

The question set includes multiple-choice questions, true/false statements, short-answer responses, a dialogue, a matching activity, a cloze passage, a labeled diagram, a reading passage, and an essay. This gives students several ways to demonstrate their understanding of natural selection and apply the ideas to different situations.

What the teacher receives

• Student worksheet: Practice covering natural selection, heritable variation, differential reproductive success, environmental pressures, trait frequencies, vocabulary, evidence-based prediction, reading, and written explanation.
• Teacher Guide PDF: Learning Objectives, Teaching Tips, Discussion Questions, and Common Mistakes to support instruction and classroom discussion.

Classroom use

Use this resource as guided or independent practice during a Grade 6 biology lesson, as a follow-up to instruction on biological evolution, or as a review activity before students move on to related evolution concepts. The varied response formats also provide opportunities to check vocabulary knowledge, scientific reasoning, reading comprehension, and written explanation within the same lesson sequence.

Because students must apply evidence to predict which traits become more common, the resource gives teachers a practical way to see whether students can connect environmental pressures and reproductive success with changes in a population over generations. The included Teacher Guide adds instructional support through targeted teaching tips, discussion prompts, learning objectives, and common-mistake guidance.

Framework: NGSS