Knock out the false energy claims

Exercise and reference answers

Questions

1. Question

   Three of these statements about energy moving up trophic levels are false.

   Choices

   1. Explanation

      Energy flows one way and leaves as heat; only matter is recycled.

      Item

      Energy is recycled back to producers

   2. Item

      Energy pyramids are always upright

      Correct

      Yes

   3. Explanation

      Only a small share crosses, near 14.8 percent at Silver Springs.

      Item

      Most energy passes to the next level

   4. Explanation

      After four to six transfers too little energy is left.

      Item

      Food chains can run to twenty levels

2. Question

   Three of these statements about biomagnification are false.

   Choices

   1. Explanation

      Concentration climbs with each trophic level, not at the base.

      Item

      Toxins peak in the algae at the base

   2. Explanation

      Its use was banned in the United States in the 1970s.

      Item

      DDT is still widely used in the States

   3. Item

      Toxins concentrate in apex consumers

      Correct

      Yes

   4. Explanation

      PCBs persist, which is why they magnify up the food web.

      Item

      PCBs break down before they build up

Instructions

Tap away the three wrong statements in each round and leave the one that stands.

Explanation