ECOLOGY

Table of Contents: 1. Lesson 1- What is Ecology? 1 2. Lesson 2- Energy Flow Through an Ecosystem 7 3. Lesson 3- Food Chains and Webs 12 4. Worksheet- Food Chain 15 5. Worksheet- Food Web 16 6. Worksheet- Food Chain QUIZ 1 & 2 17 7. Worksheet- Match the food chain 19 8. Worksheet- Trophic Levels 20 9. Worksheet- Food Webs Definition 22 10. Worksheet- Vocabulary Skills 24 11. Worksheet- Principles of Ecology (Organisms and Their Environment) 26 12. Worksheet- Principles of Ecology (Nutrition and Energy Flow) 28 13. Worksheet- Ecology: Reinforcement 30 14. Worksheet- Ecology of Organisms 31 15. Lab Exercise 1 – From Land to Mouth 33 16. Assignment 1 – Create a Concept Map 35 17. Assignment 2 – Build a Food Web or Biome Children’s Book 37 18. Assignment 3 – Human Impact on Food Chains and Webs 40 19. Glossary 42 20. Appendix – A 45

Lesson - Food Chains and Webs --- "What's for dinner?"

Every organism needs to obtain energy in order to live. For example, plants get energy from the sun, some animals eat plants, and some animals eat other animals.

A food chain is the sequence of who eats whom in a biological community (an ecosystem) to obtain nutrition. A food chain starts with the primary energy source, usually the sun or boiling-hot deep sea vents. The next link in the chain is an organism that make its own food from the primary energy source -- an example is photosynthetic plants that make their own food from sunlight (using a process called photosynthesis) and chemosynthetic bacteria that make their food energy from chemicals in hydrothermal vents. These are called autotrophs or primary producers.

Next come organisms that eat the autotrophs; these organisms are called herbivores or primary consumers -- an example is a rabbit that eats grass. The next link in the chain is animals that eat herbivores - these are called secondary consumers -- an example is a snake that eat rabbits. In turn, these animals are eaten by larger predators -- an example is an owl that eats snakes. The tertiary consumers are eaten by quaternary consumers -- an example is a hawk that eats owls. Each food chain end with a top predator, and animal with no natural enemies (like an alligator, hawk, or polar bear).

The arrows in a food chain show the flow of energy, from the sun or hydrothermal vent to a top predator. As the energy flows from organism to organism, energy is lost at each step. A network of many food chains is called a food web.

Trophic Levels: The trophic level of an organism is the position it holds in a food chain.

1. Primary producers (organisms that make their own food from sunlight and/or chemical energy from deep sea vents) are the base of every food chain - these organisms are called autotrophs.

2. Primary consumers are animals that eat primary producers; they are also called herbivores (plant-eaters).

3. Secondary consumers eat primary consumers. They are carnivores (meat-eaters) and omnivores (animals that eat both animals and plants).

4. Tertiary consumers eat secondary consumers. 5. Quaternary consumers eat tertiary consumers. 6. Food chains "end" with top predators, animals that have little or no natural enemies.

When any organism dies, it is eventually eaten by detrivores (like vultures, worms and crabs) and broken down by decomposers (mostly bacteria and fungi), and the exchange of energy continues.

Some organisms' position in the food chain can vary as their diet differs. For example, when a bear eats berries, the bear is functioning as a primary consumer. When a bear eats a plant-eating rodent, the bear is functioning as a secondary consumer. When the bear eats salmon, the bear is functioning as a tertiary consumer (this is because salmon is a secondary consumer, since salmon eat herring that eat zooplankton that eat phytoplankton, that make their own energy from sunlight). Think about how people's place in the food chain varies - often within a single meal!

Numbers of Organisms: In any food web, energy is lost each time one organism eats another. Because of this, there have to be many more plants than there are plant-eaters. There are more autotrophs than heterotrophs, and more plant-eaters than meat-eaters. Each level has about 10% less energy available to it because some of the energy is lost as heat at each level. Although there is intense competition between animals, there is also interdependence. When one species goes extinct, it can affect an entire chain of other species and have unpredictable consequences.

Equilibrium As the number of carnivores in a community increases, they eat more and more of the herbivores, decreasing the herbivore population. It then becomes harder and harder for the carnivores to find herbivores to eat, and the population of carnivores decreases. In this way, the carnivores and herbivores stay in a relatively stable equilibrium, each limiting the other's population. A similar equilibrium exists between plants and plant-eaters.

Complete the Food Chains Worksheet Circle the organisms that complete the food chains below.

Food Web Worksheet Read the passage then answer the questions below.

The arrows in the food chain

represent the flow of energy

Sun

Autotroph

primary producers

primary consumers

herbivores

top predator

producers

heterotrophs

autotrophs

producers

a producers

primary consumers

secondary consumers

Food Chain Quiz - Multiple choice comprehension questions Color the circle by each correct answer.

Food Chain Quiz #2 - Multiple choice comprehension questions Color the circle by each correct answer.

Match each Food Chain Word to its Definition.

Food Chain Trophic Levels - Worksheet

Worksheet – Introduction to Food Webs

Food Web Worksheet

Rats

Grasshoppers

mosquitos

dragon flies

lions

snake

fish

hawk

Identify the:

1. Producers

2. Primary Consumers

3. Secondary Consumers

4. Herbivores

5. Carnivores

6. Omnivores

7. What elements are missing from this food web?

The elements that are missing are the tertiary and quaternary consumers.

On the back, construct a Food web using the following animals. This ecosystem represents a farm area. The corn is the main source of food for many of the herbivores in the area. You do not have to draw pictures; you can just use the animal names and draw arrows between them.

SNAKE, CORN, CATERPILLAR, DEER, CROW, MOUSE, COUGAR, SQUIRREL, MICROORGANISMS (decomposers)

Worksheet – Food Webs

1. Define and provide examples for each of the following groups of heterotrophs.

a) Herbivores –

an organism that eats plants

Zebra

b) Carnivores –

an organism that eats meat

Snakes

c) Omnivores –

organisms that eat both plants and meat

Humans

d) Saprophytes –

organisms that eat dead organisms

vulture

e) Decomposers –

organisms that break down dead organisms

Bacteria

2. Using the organisms named below create a food web which represents the flow of energy between organisms by using arrows to connect the organisms.

(Note: You should have more then one arrow pointing towards and pointing away from any given organism.)

Lab Exercise 1 - From Land to Mouth

A field of corn contains a certain amount of food energy. If cattle eat the corn, they will gain some of the food energy. How does the amount of energy in the corn compare with the amount of energy in the cattle? Is it more efficient to feed on corn or beef? In this activity, you will compare the energy content of some familiar human foods.

You will need: graph paper, calculator, and colored pencils/markers What to do:

1. The table below lists the average amount of energy (in kilojoules per square meter of land per year) in different organisms that people use for food.

Organism Energy (KJ/m2/year) Ranking

Wheat cereal 3 400 9

Oranges and grapefruits 4 200 12

Peanuts 3 850 11

Rice 5 200 13

Potatoes 6 700 16

Carrots 3 400 8

Other vegetables 840 6

Apples 6 300 15

Peaches 3 800 10

Beet sugar 8 300 17

Cane sugar 14 650 18

Corn 6 700 14

Milk (cow) 1 800 7

Eggs (chicken) 840 5

Chicken 800 4

Pork (pig) 800 3

Beef (cow) 550 2

Fish 8 1

a. Organize the data from LEAST energy to MOST energy. (Do this under the

“Ranking” column in the table above) b. Make a bar graph to compare the relative amounts energy in each organism:

i. Include a LEGEND: Use one color for producers and another color for consumers

ii. Label bottom with the names of each organism iii. Label the left side with the energy

From Land to Mouth

YOU WILL BE USING GRAPH PAPERS THAT WILL NEED TO BE HANDED IN TO ME FOR ASSESSMENT.

2. Calculate the AVERAGE energy of all the producers.

Average: 5318.461538

3. Calculate the AVERAGE energy of all the consumers.

Average : 799.6666667

4. Which organisms (producers or consumers) can offer more energy (on average)?

The producers can offer more energy Do you think it is more efficient for people to eat plant products or animal products? Why

It is more efficient for people to eat animal products . animals have already consumed energy from plants or other animals so it gives human the highest amount of energy possible.

This material is based on work supported by the National Science Foundation under Grant No. 1054754. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Copyright © 2012 by the Center for Pre-College Programs, ofthe New Jersey Institute of Technology.All Rights Reserved. Supporting Program: Center for Pre-College Programs, at the New Jersey Institute of Technology Contributors Kunjamma Paulose ( Science Park High School, Newark, NJ), Primary Author Howard Kimmel, Levelle Burr-Alexander, John Carpinelli - Center for pre-College Programs, NJIT.