Question

1. base your answer to the following question on the diagram below and on your knowledge of biology. identify the ultimate source of energy in this food web and using evidence from the model describe how a disruption of photosynthesis affects the hawk population. 17. base your answer to the following question on the diagram below and on your knowledge of biology. the diagram represents a food web illustrating some relationships in a tidal marsh ecosystem. construct an explanation of why using pesticides and other chemicals to kill rats could have a negative impact on this ecosystem.

Explanation:

Step1: Identify energy source

The ultimate source of energy in a food - web is the sun. Plants (trees and grass in the first food - web, marsh vegetation in the second) use sunlight for photosynthesis to produce energy - rich organic compounds.

Step2: Analyze photosynthesis disruption on hawks

If photosynthesis is disrupted, plants cannot produce food. Herbivores (like rabbits, mice, deer in the first food - web) that rely on plants for food will decline. Since hawks eat herbivores (and snakes that also eat herbivores), a decrease in herbivore populations means less food for hawks, leading to a decline in the hawk population.

Step3: Analyze pesticide impact on ecosystem

Using pesticides to kill rats can have a negative impact. Pesticides can be non - selective and may kill other non - target organisms. Also, rats are part of the food chain. If their population declines, predators that rely on rats (like marsh hawks and bald eagles in the second food - web) may have less food, leading to a decline in their populations. Additionally, the pesticides can accumulate in the ecosystem through bio - magnification, affecting higher - level consumers and disrupting the overall balance of the ecosystem.

Answer:

1. The ultimate source of energy in the food - web is the sun. A disruption of photosynthesis would lead to a decline in the hawk population because it would reduce the food supply for herbivores that hawks prey on either directly or indirectly through their predators.
2. Using pesticides to kill rats could have a negative impact on the ecosystem as it may kill non - target organisms, reduce the food supply for predators of rats, and cause bio - magnification of the pesticides in the ecosystem.