GRADE: Eighth

CONTENT STANDARD: Life Science

CONTENT TOPIC: Regulation and Behavior

CONCEPT: An organism must be able to obtain and use resources to survive.

CONTENT OBJECTIVE: 8F1.00 To describe characteristics that describe living and nonliving things

INSTRUCTIONAL OBJECTIVES:

1.01 List and describe characteristics of living things
1.02 Define homeostasis

I. Unicellular
II. Multicellular
III. Classification of living things
IV. Homeostasis

TN COMPONENT OF SCIENCE: Process of Science

TN GOAL:

To enable students to demonstrate the processes of science by posing questions and investigating phenomena through language, methods and instruments of science.

1.4 ANALYZING - Data should be examined to find patterns and relationships that may suggest cause and effect or support inferences and hypotheses.

1.4 b The accuracy and precision of data should be used to determine the selection or rejection of any given piece of data.

BENCHMARK: Some means of checking for accuracy is needed because errors can occur in recording or communicating information.

BENCHMARK: The collection of data requires the most accurate degree of precision.

TIME REQUIRED:

One class period

3 sheets of black construction paper, 1 sheet of white construction paper, and scissors

Homeostasis-an organisms ability to maintain constant or stable conditions that are necessary for life.

How do you tell whether something is alive? With some living things it is easy. You could check for breathing, a pulse or a response to a pinch or poke. Such a test would not work on a tree.

Living things are made up of cells. Most cells can perform all the functions we associate with life. Cells are remarkably diverse. A single cell by itself can form an entire living organism. Organisms consisting of only a single cell are called unicellular (uni-means one, so unicellular means single celled.) Most of the organisms you are familiar with , such as dogs and trees, are multicellular.(multi-means many, so multicellular means many-celled.) Multicellular organisms contain hundreds, thousands, even trillions of cells.

Cells are never formed by nonliving things. They are found in nonliving matter only if that matter was once alive. All living things reproduce, grow and develop, obtain and use energy.

Living things respond to their environment. Such responses can be rapid, usually through changes in behavior, or slow, usually changes in growth. Anything in the environment that causes an organism to react is called a stimulus. Organisms react to many stimuli, including light, temperature, odor, sound, gravity, heat, water and pressure. What stimuli are you responding to at this very moment? (Answers may include light, sound, touch, etc....)

Living things respond to stimuli in ways that improve their chances for survival. The process by which organisms respond to stimuli in ways that keep conditions in their body suitable for life is called homeostasis ( The prefix homeo- means similar or same. The suffix- stasis means standing or stopping.) Homeostasis refers to an organisms ability to maintain constant or stable conditions that are necessary for life. Just as a thermostat in your home turns on the heat when it gets down to a certain temperature, your body has a thermostat that maintains a constant internal temperature. If you get too hot, you sweat and cool off. And if you sweat for a long time, the resulting thirst persuades you to replace the water your body has lost.

Today we have classified living things. Work with your neighbor and list and describe five characteristics that separate living and nonliving things.

Work with a partner and copy the data table

Moth Trials

Trial Number of Moths

Black Moths White Moths

Trial 1

Trial 2

Trial 3

Trial 4

1. Cut out 15 black squares 3cm x 3cm. These squares represent black moths.

2. Cut out 15 white squares 3cm x 3cm. These squares represent white moths

3. Have your partner place 2 large pieces of black construction paper on the desk. The construction paper represents the environment. While you look away, have your partner randomly place the 30 moths on the black construction paper.

4. When your partner says "ready," turn around and pick up any 12 moths as fast as you can.

5. Count the number of white and black moths that you picked. Record the results.

6. Do this 2 more times.

7. Find the total number of black moths and the total number of white moths in the three trials.

Switch roles with your partner and repeat the activity. Obtain the class totals of the black and white moths for the activity.

1. Did you pick up more white moths or black moths?

2. Which color moth would be more visible to a predator in a dark environment?

a. Which moths are better adapted to live in a dark environment?

b. In what way are these moths adapted?

c. Which moths would most likely be eaten by a bird in a dark environment?

d. Why would finding the class totals be a better sample than you and your partner's samples?

e. In the environment were light-colored, how would the results of the activity have been different?

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