Question

how much energy is lost as you move from one trophic level to the next? *
90%
50%
20%
10%
if the primary producer in an ecosystem has 20,000 joules of energy available to them, how much energy will the secondary consumer have? *
200,000 joules
20,000 joules
2,000 joules
200 joules
20 joules
how do plants use atmospheric nitrogen? *
plants use nitrogen after soil bacteria convert it into usable forms like ammonia or nitrates.
plants store nitrogen gas in their roots until it becomes usable.

Explanation:

1. In an ecosystem, about 90% of energy is lost as you move from one trophic level to the next due to metabolic processes like respiration, heat loss etc.
2. Energy transfer between trophic levels follows a 10 - 10% rule. Primary producer to primary consumer is 10% transfer, and then primary consumer to secondary consumer is another 10% transfer. So if primary producer has 20,000 joules, primary consumer has 20,000×0.1 = 2,000 joules and secondary consumer has 2,000×0.1=200 joules.
3. Plants cannot use atmospheric nitrogen directly. Soil bacteria convert atmospheric nitrogen into usable forms such as ammonia or nitrates which plants can then take up.

Answer:

1. 90%
2. 200 joules
3. Plants use nitrogen after soil bacteria convert it into usable forms like ammonia or nitrates.