Question

1. only ____ percent of the energy captured by producers is available at the tertiary food level.

a. 1
b. 0.001
c. 0.01
d. 0.1

1. what is likely to be the effect of removing a primary producer from an ecosystem?

a. herbivores would adapt and find a new plant based food source
b. herbivores would begin to prey on other animals
c. the species of herbivore that feeds on that plant would be extinguished
d. none of the above

1. organisms burn food energy for

a. heat
b. growth
c. locomotion
d. all of the above

1. why does a food pyramid only have four or five trophic levels before it ends?

a. there isn’t enough energy to pass along to another trophic level
b. an organism at the next trophic level would have to be too huge to live
c. the world would be too hot from all the excess heat
d. all of the above

1. the width of the pyramid at each trophic level represents the number of organisms at that level.

a. true
b. false

1. most of the energy that powers all ecosystems on earth comes from the sun.

a. true
b. false

Explanation:

1. In an ecosystem, only about 10% of energy is transferred from one trophic level to the next. From producers to primary - consumers (10%), then to secondary - consumers (10% of the 10% = 1%), and then to tertiary - consumers (10% of 1% = 0.1%).
2. Primary producers are the base of the food - chain. Herbivores that specifically depend on a particular primary producer would likely go extinct if that producer is removed as they may not be able to adapt quickly enough to find a new food source, and they do not typically prey on other animals.
3. Organisms use food energy for heat (maintaining body temperature), growth (building and repairing tissues), and locomotion (movement).
4. The main reason a food pyramid has only four or five trophic levels is that there is not enough energy to pass along to another trophic level due to the 10% energy - transfer rule. Also, an organism at a higher trophic level would need to be extremely large to survive on the limited energy available, and the excess heat generated during energy transfer could also be a factor.
5. The width of a food pyramid at each trophic level represents the amount of energy or biomass at that level, not the number of organisms.
6. The sun is the primary source of energy for most ecosystems on Earth through the process of photosynthesis in primary producers.

Answer:

1. d. 0.1
2. c. The species of herbivore that feeds on that plant would be extinguished
3. d. All of the above
4. d. All of the above
5. b. FALSE
6. a. TRUE