Every time energy is transferred between organisms in a food web, some of the energy is lost as heat

In every level of the food chain is lost the 90 % of energy.

Explanation:

That means that the total energy taken from the sun, the 10 %  is lost in the next step ( the primary consumers) and just the 1% pass to the second consumers, and just the 0.1 % pass to the third consumers. The 90 % of energy that is lost between one level and the second, the living thing uses to their movements, the metabolism, etc.

your answer is "the 1950's"

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.