Question

1. which of the following is a biotic factor?

a. the ph of a soil sample.
b. bacteria present in a water sample.
c. levels of nutrients present in soil.
d. the changing of tides in the ocean.

1. which of the following would not be considered an abiotic activity?

a. the melting of ice in the spring.
b. oxygen dissolving in moving water.
c. production of air pollution by humans.
d. the process of photosynthesis.

Explanation:

1. Biotic factors are living components. Bacteria are living organisms. pH, nutrients (non - living), and tides (physical) are abiotic.
2. Abiotic activities involve non - living components. Photosynthesis is a biological (biotic) process carried out by plants. Melting ice (physical), oxygen dissolving (physical - chemical), and human - made air pollution (human - made non - living in this context) are abiotic.

Answer:

1. B. Bacteria present in a water sample.
2. D. The process of photosynthesis.