Explain the 10% rule. Include the two ways in which energy can be lost from the food chain

The 10% rule in ecology refers to the fact that, on average, only about 10% of the energy from an organism is transferred to its consumer. This rule is a rough estimate and can vary depending on the specific ecosystem and the organisms within it.

Here's a step-by-step explanation:

1. Primary producers, like plants, capture energy from the sun through photosynthesis. This energy is stored in the plant's tissues.

2. When a primary consumer, like a herbivore, eats the plant, it gains energy from the plant's tissues. However, only about 10% of the energy the plant captured from the sun is transferred to the herbivore. The rest is lost.

3. The same rule applies when a secondary consumer, like a carnivore, eats the herbivore. Only about 10% of the energy the herbivore gained from the plant is transferred to the carnivore.

4. This continues up the food chain, with each level only receiving about 10% of the energy from the level below it.

Energy can be lost from the food chain in two main ways:

1. Through waste: Not all parts of the food are digestible, so some energy is lost through excretion.

2. Through respiration: Organisms use energy for their metabolic processes, like growth and reproduction. This energy is lost as heat during respiration.

In summary, the 10% rule explains why energy pyramids are typically 'pyramid' shaped - with a large amount of energy at the bottom (from primary producers) and less energy as you move up the food chain to primary consumers, secondary consumers, and so on.