Question

iii. big ideas

1. one hypothesis regarding the extinction of dinosaurs is that a meteor hit the earth causing an explosion so powerful that dust blocked out the sun. consider the model above and explain why this would have caused a mass extinction.
2. when you walk your dog, you are using energy from the sunlight to power this activity. explain.
3. carefully and completely answer the essential question of this activity. use complete sentences and details from the model to explain your position.

essential question: what is the relationship between photosynthesis and respiration?

Explanation:

11.

Plants rely on sunlight for photosynthesis. Without sunlight due to dust - blocked sun, plants die. Herbivores that eat plants starve, and then carnivores that eat herbivores also starve, leading to mass extinction.

Plants use sunlight for photosynthesis to produce energy - rich molecules like glucose. Animals (including humans) eat plants or plant - eating animals. The energy originally from sunlight is transferred through the food chain to power human activities like walking a dog.

Photosynthesis in plants uses carbon dioxide and water, powered by sunlight, to produce oxygen and glucose. Respiration in plants and animals uses oxygen to break down glucose for energy, producing carbon dioxide and water. They are opposite but complementary processes.

Answer:

The blocking of sunlight by dust from the meteor - explosion would have stopped photosynthesis in plants. Since plants form the base of the food chain, the death of plants would have caused a chain - reaction of starvation among herbivores and then carnivores, resulting in mass extinction.

12.