1.
Ladybugs eat aphids, which are a source of protein for the ladybugs. Which of these terms best describes the relationship between the ladybugs and the aphids?
Correct Answer
C. Predator–prey
Explanation
Ladybugs kill and eat aphids. This makes the ladybug a predator.
2.
Aphids are insects that feed on fluids from the stems of plants. After the aphids ingest the plant fluids, they excrete a liquid called honeydew.Some species of ants protect aphids from predators. The ants benefit by feeding on the honeydew produced by the aphids. Which of these terms best describes the relationship between the aphids and the ants?
Correct Answer
A. Mutualism
Explanation
Both organisms benefit. The aphid gets free protection by the ant and the ant gets food.
3.
As you move up the trophic levels from producers to second order consumers, you would expect the see the amount of available energy _____________.
Correct Answer
A. Decrease
Explanation
There is less energy available to each level of consumer because some of the energy is converted ("used") by the organisms in the previous trophic level.
4.
On Earth, water cycles through the atmosphere, oceans, land, and organisms. By what process does most of the water in plants return to the environment?
Correct Answer
C. Evaporation from the leaves
Explanation
Roots are used to absorb water, not to release it into the environment, so a and d are incorrect. Condensation on leaves would bring water to the plant, but not return it to the atmosphpere. Evaporation from leaves is the only correct choice. This is also called transpiration.
5.
Which of these describes the role of the sanderling in the marine food web below?
Correct Answer
C. Carnivore
Explanation
The arrow pointing to the sanderling from the horseshoe crab shows that the sanderling consumes the crab for food. There are no arrows showing that the sanderling consumers any plants. Therefore, it is a meat-eater, or a carnivore.
6.
Horseshoe crabs are used by fisherman for bait. If the horseshoe crab population were reduced by overfishing, which of these groups of organisms would most likely decrease in number?
Correct Answer
B. Sanderlings, loggerhead turtles, and striped bass
Explanation
They would all lose their main source of food.
7.
Scientists classify humans as omnivores, based on their teeth. As omnivores, humans eat _____.
Correct Answer
B. Mostly plants and animals
Explanation
Think of the definition of an omnivore. That's all there is to it!
8.
How would the populations of other organisms in the energy pyramid be affected if the population of sea urchins suddenly decreased?
Correct Answer
D. The kelp population would increase, and the sheepHead population would decrease.
Explanation
Kelp increases because there are fewer sea urchins eating it. Sheephead population decreases because there are fewer urchins for food.
9.
What is the lowest level of the energy pyramid that contains carnivores?
Correct Answer
C. Level 3
Explanation
The lowest level of the energy pyramid that contains carnivores is Level 3. In an energy pyramid, each level represents a trophic level, with producers at the bottom and top-level predators at the top. Carnivores are usually found at the third trophic level, as they feed on herbivores that are at the second trophic level. This is because energy is transferred from one trophic level to another, and the energy available decreases as it moves up the pyramid. Therefore, carnivores are typically found at a higher trophic level than herbivores.
10.
A student used a microscope to observe several protists. The student sketched the protists and recorded their magnifications. The drawings and measurements are shown below.Which of these protists is the largest?
Correct Answer
A. Difflugia
Explanation
A and B are magnified only 4 times, so they are larger than C and D, which had to be magnified 10 times to be seen clearly. Between A and B, A (Difflugia) appears the largest.