Ecosystems: Fourth Grade Study Guide Key
Test is on Wednesday, September 14, 2016
Standards:
S4L1. Students will describe the roles of organisms and the flow of energy within an ecosystem.
a. Identify the roles of producers, consumers, and decomposers in a community.
b. Demonstrate the flow of energy through a food web/food chain beginning with sunlight and including producers, consumers, and decomposers.
C. Predict how changes in the environment would affect a community (ecosystem) of organisms.
d. Predict effects on a population if some of the plants or animals in the community are scarce or if there are too many.
S4L2. Students will identify factors that affect the survival or extinction of organisms such as adaptation, variation of behaviors (hibernation), and external features
(camouflage and protection).
a. Identify external features of organisms that allow them to survive or reproduce better than organisms that do not have these features (for example: camouflage,
use of hibernation, protection, etc.).
b. Identify factors that may have led to the extinction of some organisms.
Understand how to use your vocabulary words to explain the standards consumer, producer, decomposer, ecosystem,
food chain, food web, population, adaptation, camouflage, instinct, hibernation, extinction, community, population,
organism, flow of energy, scarce, external, features, factors
Understand these concepts:
1. What is the relationship between producers, consumers, and decomposers?
Producers make their own food to grow and become energy for the consumers that eat them. Consumers help to
control the population of producers by eating them so that the nutrients in the soil will not be depleted (or gone).
Decomposers break down wastes into nutrients which can be used by living things
2. Why are there fewer organisms at the top of an energy pyramid?
Each level in a pyramid passes so little energy (about 10 %) to the consumers in the next level, so more producers
and first level consumers are needed to provide food for the higher-level consumers.
3. Is a food web or a food chain more accurate? Explain and be able to draw a food chain and web, beginning with
sunlight.
A food web is more accurate as it shows all the foods an animal eats in a particular ecosystem. A food chain just
shows the energy from one food source to another.
4. How does climate impact an ecosystem?
A climate change can affect a specific organism which could deplete the number of that organism available for the
consumers. In turn, that would affect the number of level-one consumers, which affects the level-two consumers,
and on and on.
5. How can species that eat the same foods share the same habitat?
Species that eat the same foods can share the same habitat as long as there is a balance of the animals and the
foods they eat. For instance, if one species becomes greater in number and they are stronger than the other
species, they will eat all the food and there will not be enough for the other species.
6. What are some of the reasons why a species may become extinct?
Climate change, pollution, and human activities, such as clearing of trees to build homes and businesses,
introduction of organisms that are not native to the area, such as kudzu vines and Chinese privet which take over
native plants.
7. What would happen if there were no plants on Earth?
If there were no plants on Earth, the organism that need oxygen would die because plants convert carbon dioxide
emitted by animals to oxygen, which animals need to survive.
8. Why do animals have adaptations? Name some adaptations animals have in order to survive.
Animals have adaptations to help them survive in their environment. Behavioral adaptations: instincts the animals
have from birth, such as some animals living in herds, Hibernation, and migration. Physical adaptations:
Camouflage, and specific body parts, such as the snowshoe hare fur turns white in the winter to hide it from
predators. Protection: Skunks have an odor which will keep predators away.