To answer the first question, we are looking for something that is not a biotic factor in the ecosystem described. Biotic factors are living organisms that can influence an ecosystem. The options given are: A) temperature, B) hawks, C) beavers, D) fir trees.
In order to determine which of these is not a biotic factor, we need to understand what biotic factors are. Biotic factors include all the living organisms in an ecosystem, such as the perch, bass, ducks, crayfish, frogs, and water snakes mentioned in the description. Fir trees are also mentioned, so they do fall under the category of biotic factors. Therefore, the answer should not be D) fir trees, as it is a biotic factor.
To answer the second question, we need to identify an abiotic factor that would not affect the ecosystem described. Abiotic factors are non-living elements that shape an ecosystem. The options given are: A) temperature, B) rainfall, C) type of soil, D) water snakes.
In the given pond ecosystem, all the options except D) water snakes are abiotic factors. Temperature, rainfall, and the type of soil are all non-living elements that can affect the ecosystem's dynamics. Water snakes, on the other hand, are living organisms and therefore classified as biotic factors.
Therefore, the final answer the first question is D) fir trees, and the answer to the second question is D) water snakes.