Question

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:

1. Ultimate energy source: The sun is the ultimate source of energy in the food - web. Plants (trees and grass) use sunlight to perform photosynthesis, converting solar energy into chemical energy stored in their tissues.
2. Effect on hawks if photosynthesis is disrupted: If photosynthesis is disrupted, plants will not be able to produce food. Herbivores (like rabbits, mice, crickets) that rely on plants for food will decline in number due to lack of food. Since hawks feed on these herbivores and also on snakes that feed on herbivores, the reduction in herbivore populations will lead to a decrease in the food supply for hawks, causing the hawk population to decline.
3. Impact of using pesticides on the ecosystem: Pesticides used to kill rats can have a negative impact on the ecosystem. First, non - target species may be affected. For example, other small animals that come into contact with the pesticides may be poisoned. Second, the chemicals can accumulate in the food - web. Predators that eat the poisoned rats (such as bald eagles) may be affected by the pesticides through biomagnification, leading to health problems and population declines in these higher - level consumers. Also, the removal of rats may disrupt the food - web balance as rats are part of the diet of some animals and also play a role in controlling plant populations in some cases.

Answer:

1. The ultimate source of energy is the sun. Disrupting photosynthesis would cause a decline in the hawk population as it would reduce the food supply for herbivores that hawks prey on directly or indirectly.
2. Using pesticides to kill rats can harm non - target species, cause biomagnification in predators, and disrupt the food - web balance.