1. Calculate If 1000 units of energy are available at the producer level of the energy pyramid, about
how many units are available for first-level con-
sumers? Second-level consumers? Third-level
consumers?

first-level consumers- about 100units

Second-level consumers- about 10units

Third-level consumers- about 1unit

Explanation:

A food chain represents the series of energy transfer from one organism to another. This energy is transferred when one organism feeds on another organism. A food chain always starts with a PRODUCER, which is an organism capable of producing its own food via photosynthesis. The producer creates the energy that is transferred as the food chain progresses.

However, only about 10% of the available energy in one organism is transferred to another, this is because most of the energy (about 90%) is lost as heat when the organism undergoes metabolic activities. Hence, if 1000units of energy are available at the producer level, a primary/first level consumer will feed on the producer and 10/100 × 1000 = 100units of energy will be available for the primary/first level consumer.

Likewise, 10% of 100units= 10 units of energy will be available for the second level consumers when it feed on the first level consumers. Lastly, 10% of 10units = 1 unit will be available for third level consumer when it feeds on second level consumer.

the answer is d. chordata