Unit 3 Ecosystems Chapter 6 & 7

Questions #3-9 in the book Part 1 The Web Of Life p. 92 & Food Relationships p. 93 Questions #3-9 in the book

Define Ecosystem Ecosystem = the network of relationships (interactions) among living (plants, animals) and the non-living parts (soil, climate, water etc.) in an environment.

Differentiate the terms producers, consumers decomposers. P. 93 Other examples: Grasses Trees shrubs Water lilies Flowers Vegetables Fruits Producer = a plant which can synthesize carbohydrates using carbon dioxide and the sun’s energy. Actually “produce” their own food and food for the rest of the ecosystem

Differentiate the terms producers, consumers, decomposers. P. 93 Consumers = All those organisms that have to eat (consume) plants or animals to obtain their food.

Types of consumers Primary Consumers: Animals that eat producers. Also called 1st. order consumers. (Ex. Rabbit, squirrels, grouse, insects) Secondary Consumers: Animals that eat primary consumers. Also called 2nd. order consumers. (fox, owl, mink ) Tertiary Consumers: Animals that eat secondary consumers. Also called 3rd. order consumers. (Wolf, coyote, hawk)

Differentiate the terms producers, consumers, decomposers. P. 94 Examples: Worms Bacteria Fungi Protozoa Decomposers = Simple organisms that obtain their food from dead/decaying organisms and wastes.

Differentiate the terms food chain & food web. P. 94 Food chain = linear sequence representing the nutrition of various species from the simplest plant to the top carnivore. Food web = a series of interconnecting food chains in an ecosystem. Food web is more complex and is composed of several food chains Food web is a more realistic picture of an ecosystem.

Food Chain vs Food Web

Identify ALL examples of each trophic level. Producers Primary Consumers Secondary Consumers Tertiary Consumers Decomposers Shrubs, grass, trees Grasshopper, rabbit, deer, squirrel Mountain lion, snake, shrew, insect-eating bird, hawk Hawk, snake, mountain lion Bacteria, fungi

Give an example of a food chain from fig. 6.4. P. 95 Tree → insect insect eating bird hawk Producer Primary consumer 2nd order consumer 3rd order consumer Note: The arrows indicate the flow of energy & nutrients from one level to the next

Sample Food Chain

Draw an example of a food web containing humans. P. 94 Mosquito Hawk Cow Grass Man Decomposer Phytoplankton Fish

Draw an example of a food web containing humans. P. 94 Hawk Mosquito Cow fish Man Phytoplankton Grass Decomposer

What happens to energy? (Handout)

What happens to energy? 10-15% is stored: 85-90% is LOST or USED up: Available or transferred to other animals when it is eaten. 85-90% is LOST or USED up: maintaining the organism (Ex. metabolism, reproduction etc.) And as heat!!! IF NOT EATEN: Energy is transferred to the decomposers.

What happens to the energy at the decomposer level? Same thing….ALMOST !? Most is lost or used up through heat and maintaining the organism. If eaten (Ex. A mushroom) energy gets passed on. HOWEVER, once a decomposer dies…. The energy is LOST FOREVER!!!

Summary – Energy & Food Webs The ultimate source of energy (for most ecosystems) is the sun The ultimate fate of energy in ecosystems is for it to be lost as heat, metabolism, reproduction, etc.. Energy and nutrients are passed from organism to organism through the food chain as one organism eats another. Decomposers remove the last energy from the remains of organisms. Inorganic nutrients are cycled, energy is not.

Summary – Energy & Food Webs Question #14, 15 & #16 p. 98 make perfect review questions for the test.