Original Promptidentical and faternal twins
This resource explores the science of twins, focusing on the biological mechanisms behind identical (monozygotic) and fraternal (dizygotic) twins. It begins with an advance organizer prompting students to connect their prior knowledge of meiosis and fertilization, specifically asking about the sperm's role in fertilizing an egg. The introductory passage details the distinct pathways of twinning: monozygotic twins arise from a single egg fertilized by one sperm, leading to two embryos that share 100% DNA; whereas dizygotic twins emerge from two different eggs fertilized by separate sperm, sharing only about 50% of their DNA. The resource includes activities such as summarizing main ideas, identifying biological differences, and discussing the significance of genetic similarities, along with visual aids and diagrams comparing monozygotic and dizygotic development. It culminates in reflective questions that encourage deeper understanding and the ability to communicate concepts clearly.