Question

part a: which trophic level has the least biomass? part b: select a number in each set of options to describe the energy available to organisms in the energy pyramid if the phytoplankton contain 10,000 kcal organisms in level contain kcal

Explanation:

Step1: Recall biomass - trophic level relationship

In an energy pyramid, biomass generally decreases as trophic level increases.

Step2: Identify highest trophic level

The shark (level 1) is at the highest trophic level in this pyramid.

Step3: Recall energy - trophic level rule

Only about 10% of energy is passed on from one trophic level to the next. Phytoplankton are at level 5 with 10,000 kcal. To find energy at level 4 (crustaceans), we calculate 10% of 10,000 kcal.
\[10000\times0.1 = 1000\text{ kcal}\]
To find energy at level 3 (herring), we calculate 10% of 1000 kcal.
\[1000\times0.1=100\text{ kcal}\]
To find energy at level 2 (mackerel), we calculate 10% of 100 kcal.
\[100\times0.1 = 10\text{ kcal}\]
To find energy at level 1 (shark), we calculate 10% of 10 kcal.
\[10\times0.1=1\text{ kcal}\]

Answer:

Part A: Shark (level 1)
Part B: For example, if we consider level 1 (shark), it contains 1 kcal; if level 2 (mackerel), it contains 10 kcal; if level 3 (herring), it contains 100 kcal; if level 4 (crustaceans), it contains 1000 kcal.