Question

1. a balanced aquarium with plants, fish, and detritus - eaters is considered a/an __ system because a) open; it exchanges matter with the surrounding environment b) open; it exchanges energy with the surrounding environment c) open; it exchanges both energy and matter with the surrounding environment d) closed; it doesnt exchange matter or energy with the surrounding environment 50) abundant plants supporting an increase in the rabbit population is an example of feedback, and few rabbits allowing for an abundance of plants is an example of __ feedback. a) negative; positive b) positive; negative c) negative; negative d) positive; positive

Explanation:

1. An open - system exchanges matter and energy with its surroundings. A balanced aquarium with plants, fish, and detritus - eaters exchanges matter (such as gases and nutrients) and energy (light energy for photosynthesis etc.) with the environment, so it is an open system.
2. In a positive feedback loop, a change leads to an amplification of that change. When there are few rabbits, plants are abundant, which allows for an increase in the rabbit population. This increase in rabbits will further affect the plant population, and this cycle can be seen as a positive - positive scenario in terms of the initial increase in rabbit population being enhanced by available resources.

Answer:

1. A. open; it exchanges matter with the surrounding environment
2. A. negative; positive