Name:__________________________________
Science Notes/Study Guide
Date:____________
Mrs. Thal
#____
Unit A, Chapter 4, Lessons 1-4
Lesson 1 – What Makes Up an Ecosystem?
Definitions
Ecosystem: all the living and nonliving parts in an area
Ecology: the study of relationships among living and nonliving parts of an area
Habitat: the place where a species lives
Niche: the role of a species in an ecosystem
Population: all of the members of one species that live in the same area
Community: all the populations living together in one area
Questions
1. Where do almost all the nutrients in a tropical rainforest come from? Inside living things
2. What is the sunlight and temperature like in a rainforest? Same amount of sunlight every
day all year long; temperature is always warm; there are no short days
3. Where do howler monkeys spend most of their time? High in trees
4. In the rainforest, howler monkeys and leaf cutter ants are part of the same community.
5. What happens to the nutrients inside a living thing when it dies in a rain forest? Decomposers
break it down and release its nutrients. Then plants reuse those nutrients for growth.
Lesson 2 – How Do Living Things Get Energy?
Definitions
Photosynthesis: the process by which plants use sunlight to make sugar from water and
carbon dioxide
Producer: an organism the uses sunlight to make sugar from water and carbon dioxide
Consumer: an organism that consumes other organisms for food
Scavenger: an animal that feeds on the bodies of dead organisms
Decomposer: an organism that helps decay dead organisms and the wastes of living
organisms
Questions
1. Plants aren’t the only organisms that can carry out photosynthesis. What else can? Some
single-celled (one celled) organisms. They live mainly in the oceans.
2. Consumers that eat only plants are called herbivores. Consumers that eat other consumers
are called carnivores. Consumers that eat both plants and animals are called omnivores.
Lesson 3 – How Does Energy Move Through an Ecosystem?
Definitions
Energy Pyramid: A diagram that compares the amount of energy available at each position,
or level, in the feeding order
Food Web: A combination of all the food chains in a community
Questions
1. What is a food chain? It shows a simple view of how energy and nutrients pass through
an ecosystem.
2. Why does the amount of available energy decrease as you move up the energy pyramid?
Each organism uses some energy for its life processes. Most of it is lost as heat.
3. Describe the first level in an energy pyramid. It is the largest level, with the most energy.
It represents the energy trapped by all of the producers.
4. How is a food web different from a food chain? A food web shows all the relationships that
can exist between different organisms. One organism might be food for several different
organisms.
5. Does the removal of a predator form a food web always have a positive effect on the food
web? Explain. No, because other organisms under the predator in the food web might
increase in population, but their food supply would not increase. There might not be
enough food for them all.
Lesson 4 – What are some Natural Cycles in an Ecosystem?
(No definitions for this lesson)
Questions
1. Name 3 natural cycles in an ecosystem. Carbon dioxide-oxygen, nitrogen, water
2. In the carbon dioxide-oxygen cycle, what do consumers give off that producers need?
Carbon dioxide
3. What process is the opposite of photosynthesis? respiration
4. In the nitrogen cycle, some bacteria in the soil can combine nitrogen gas from the air with
other substances to form nitrogen compounds.
5. Plants use nitrogen compounds to make proteins.
6. How does water cycle through the nonliving part of an ecosystem? Water evaporates from
the land and oceans and forms water vapor, it condenses and then comes back down to
earth as precipitation.