CER (Claim, Evidence, and Reasoning) (worth 15 pts)
Information: The leading scientific hypothesis for the extinction of the non-avian dinosaurs and a wide variety of other species 65 million years ago is a massive asteroid impact. Evidence from this period includes a global layer of iridium, an element rare on Earth but common in asteroids. This event is believed to have ejected vast amounts of dust, ash, and aerosols into the atmosphere, causing a prolonged "impact winter." Historical events, such as the 1815 eruption of Mt. Tambora, provide a small-scale analogue: this massive volcanic eruption ejected so much debris into the atmosphere that it significantly blocked sunlight, leading to global cooling, crop failure, and famine for over a year. Dinosaurs, being large ectothermic reptiles, would have been particularly vulnerable to sudden environmental changes.
Question: Using the provided information and your knowledge of biology, evaluate the hypothesis that a large asteroid impact led to the mass extinction of the dinosaurs.
A. Claim State your claim by answering the question. Use the word "because" in your answer to provide a brief rationale. (3 pts)
B. Evidence Provide at least three distinct pieces of evidence from the provided information that support your claim. You may use bullet points. (6 pts)
C. ReasoningUsing scientific principles, explain how your evidence supports your claim. Your reasoning must connect the effects of an asteroid impact to the concept of photosynthesis and the structure of food webs to explain the chain of events that could have led to a mass extinction. (6 pts)
See the rubric to ensure you get the greatest amount of points for your answer.