1. Name an organism that may be placed at level A
Which statement about the
pyramid of energy shown
here is correct?
(1) The amount of energy needed to sustain the pyramid enters at
level D.
(2) The total amount of energy decreases with each successive
feeding level from D to A.
(3) The amount of energy is identical in each level of the pyramid.
(4) The total amount of energy at level D is less than the total
amount of energy at level B.
Name an organism that may be placed at level A
(1) Heterotrophs
(2) Omnivores
(3) A maple tree
(4) A lion

2. Populations

3. How do populations grow?

4. The basics of population growth:
Populations grow if more are born than die.
Populations are at equilibrium (stable) if birth rates = death rates
Populations shrink if more die than are born.

5. Do growth conditions remain good forever?
If conditions are right (enough food, space, etc.), a population will grow.
Do growth conditions remain good forever?

6. NO!
WHY?

7. The maximum number of a population that can live in a given ecosystem.

8. The graph shows
the changes in the
size of a fish
population over a
period of time.
The dashed line on the graph represents the
(1) carrying capacity of the environment
(2) life span of the species
(3) level at which extinction is reached
(4) level of maximum biodiversity of the species

9. Are predators bad?

10. Predators are important…
They must also survive

11. Predators are important…
They must also survive They remove weak and sick animals from prey population (natural selection!)

12. Predators are important…
They must also survive They remove weak and sick animals from prey population (natural selection!) Keep prey from overpopulating

14. The graph shows changes in the populations of two species that interact only with each other over a
period of time.
Which statement best describes these two species?
Species A is a producer and species B is its consumer.
(2) Species A is a host and species B is its parasite.
(3) Species A is a predator and species B is its prey.
(4) Species A is a scavenger and species B is its decomposer.