Download Chapter 5 - Spokane Public Schools

Chapter 5
Ecosystems
Name ____________________________________
Life Science
1. Higher Levels of Organization – Organisms can be grouped into what we call the higher
levels of organization. These levels include:
1) Individual organism.
2) Populations – Members of the same species are grouped into populations (people, pine
trees, white-tailed deer, snow shoe rabbits etc.).
3) Communities – Groups of populations together make up communities (Spokane).
4) Ecosystems – Different communities together with their physical surroundings make up
ecosystems (forest, grassland, marsh, lake, etc.)
5) Biosphere – All of the ecosystems together form the biosphere (Earth). (84)
2. Producers & Photosynthesis – Most ecosystems get their energy first from sunlight. Light
energy from the sun is changed to chemical energy that can be used by organisms in a process
called photosynthesis. Producers (plants) are the only living things that produce and store
their own food using energy from the sun (photosynthesis). (86)
3. Consumers – Living things in an ecosystem that get energy by consuming (eating) other
organisms are called consumers (animals). (86)
4. Herbivore – A consumer that eats only plants is called an herbivore. (86)
5. Carnivore – A consumer that eats only other animals is called a carnivore. (86)
6. Omnivore – A consumer that eats both plants and animals is called an omnivore. (86)
7. Decomposer – A living thing that breaks down waste and dead things for food is called a
decomposer (mushrooms, mold, bacteria). (86)
8. Energy Flow – Energy flows from the sun, to producers, to consumers, and finally to
decomposers in an ecosystem. Energy is lost at each step of the flow. It is usually lost as
unusable heat. (87)
9. Nutrients – Elements and compounds needed for an organism to stay alive are called
nutrients (water, oxygen, carbon, calcium, etc.). Nutrients are continually cycled and reused in
an ecosystem. They are not lost. Decomposers are very important in returning nutrients back
into the ecosystem. (87)
10. Water Cycle – The cycle that continually replenishes our water supply is the water cycle. It
is driven by energy from the sun. (88)
11. Carbon & Oxygen Cycle – Carbon is present in both the air and water as carbon dioxide.
Oxygen is also present in both the air and the water. During photosynthesis producers
(plants) take in carbon dioxide and release oxygen. Consumers (animals) take in oxygen and
give off carbon dioxide. This continually recycles carbon and oxygen. (88)
12. Food Chain – A food chain shows how each member of an ecosystem gets its food. Food
chains always start with the sun and a producer. There are more producers than there are
herbivores, carnivores, or omnivores in an ecosystem. The amount of energy passed along
becomes less and less as you move up the food chain. (90)
13. Energy Pyramid – A good way to show how energy moves from one feeding level to
another in a food chain is called an energy pyramid. As you move up the pyramid the
diagram gets smaller and smaller to show that there is less and less energy as you move up
the chain. There is also less biomass.(91)
14. Biomass – The actual mass (weight) amount of living organisms that exist at any level of the
food pyramid is called biomass.
15. Food Web – A group of overlapping food chains connected together in an ecosystem is
called a food web. A food web shows that most animals eat more (or are eaten by more) than
one thing and can therefore be part of several different food chains in an ecosystem. (92)
16. Competition – When members of an ecosystem depend on the same limited supply of food
this creates what is called competition. (94)
17. Predators and Prey – Animals that hunt down and feed on other animals are called
predators (wolf, lion). The animals they hunt are called prey (deer, rabbit). (94)
18. Symbiosis – Symbiosis is an interaction in which two species live together for a long period
of time and at least one (or both) benefit (shark and remora). (94)
19. Population – A group of organisms from the same species that live together and reproduce
in an area is called a population. (95)
20. Growth Rate – The change in size of a population over time is called the growth rate. (95)
21. Invasive Species – When a species that doesn’t belong finds its way into an ecosystem it is
known as an invasive species. (96)
22. Pollutant & Toxins– Something that causes harm to an organism is called a pollutant
(sulfur dioxide in the air, mercury in the water). Human activity can create poisonous
pollutants. These are called toxins. Toxins can cause slowed growth, decreased reproduction,
and even death. Plants absorb toxins from the environment. The toxins are passed on to
animals when they eat the plants. Animals store the toxins in body fat and pass it on when
they are eaten. Toxins can therefore actually multiply as you go up the food chain. They can
even be passed on to the young. (97)
23. Water Quality – There are several tests to measure water quality:
1) Temperature Test – Very warm water will not hold much dissolved oxygen.
2) Turbidity Test – This tests how cloudy the water is. Clean water allows more sunlight.
3) Dissolved Oxygen Test – This measures the amount of dissolved oxygen, critical for life,
that is in the water.
4) Biological Oxygen Demand Test – Determines how much oxygen is being used by
bacteria as they decompose things in the water.
5) Nitrate & Phosphate Tests – These are tests for chemicals that have entered the water
from fertilizers, septic tanks, and farm animals. High amounts mean the risk of high algae
growth that decomposers feed on, lowering oxygen levels.
6) pH Test – This tests for how acidic the water is. (99-100)