Characteristics of Living
Organisms
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Printed: January 21, 2015
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C HAPTER
Chapter 1. Characteristics of Living Organisms
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Characteristics of Living
Organisms
Key Concepts
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Characteristics of living things
Overview of cells
Definition of stimulus and response
Comparison of sexual and asexual reproduction
Meaning of homeostasis
Standards
Lesson Objectives
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Identify characteristics of living organisms.
Describe cells.
Explain why living things need energy.
Give an example of a stimulus and response.
Compare sexual and asexual reproduction.
Define homeostasis.
Lesson Vocabulary
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cell: Unit of structure and function of all living things.
energy: Ability to change or move matter.
homeostasis: Condition in which an organism maintains a stable internal environment.
reproduction: Production of offspring.
response: Reaction to a stimulus by a living organism.
stimulus: Something in the environment that causes a reaction in an organism.
Teaching Strategies
Introducing the Lesson
Ask students to make a list of things that are alive and another list of things that are not alive. Call on volunteers to
read their lists to the class. Guide students in comparing the two lists so they can start to develop a working definition
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of what it means to be alive. Ask the class what the living things on the list have in common and how they differ
from the things that aren’t alive. Tell students they will learn the characteristics of living things when they read this
lesson.
Demonstration
Do the simple "Sewer Lice" demonstration described at the following URL for a light-hearted way to generate a
discussion of the characteristics of living things. Students will be grossed out when you show them that the "lice"
(actually raisins) are edible. The demonstration will definitely engage them, illustrate the importance of careful
observations, and start them thinking about the distinction between living and nonliving things.
http://www.nclark.net/SewerLice.pdf
Cooperative Learning
Challenge teams of students to invent a new organism. It should have structures for performing all of the functions
of a living thing. Team members should make models or sketches of their organism and explain how it functions to
the rest of the class.
Building Science Skills
The activity at the link below can be done as a class project or an individual assignment. In the activity, students
will read about and see videos of various organisms or living cells. Then they will identify and describe observable
characteristics of life in the videos.
http://www.exploratorium.edu/imaging-station/activities/classroom/characteristics/ca_characteristics.php
Differentiated Instruction
Explain to students how acronyms can be used to remember information, particularly lists of related information.
Share with them the popular acronym "MRS GREN." It can be used to remember the characteristics of living things:
TABLE 1.1: MRS_GREN
M
R
S
Movement
Respiration
Sensitivity
G
R
Growth
Reproduction
E
N
Excretion
Nutrition
All living things move, even plants
Getting energy from food
Detecting changes in the surroundings
All living things grow
Making more living things of the
same type
Getting rid of waste
Taking in and using food
Enrichment
Select two small groups of students to research and debate the issue of whether viruses should be considered living
things. The URLs below are excellent resources to start their research. Give the students an opportunity to debate
the issue in front of the rest of the class.
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Chapter 1. Characteristics of Living Organisms
http://serc.carleton.edu/microbelife/yellowstone/viruslive.html
http://www.scientificamerican.com/article/are-viruses-alive-2004/
http://news.discovery.com/videos/are-viruses-alive.htm
Science Inquiry
Have groups of students do the "Moon Walkers" inquiry activity at the following URL. They will assume that they
are scientists from the moon of another planet and that they have been sent to Earth to investigate possible new life
forms. They will also assume that they have captured two specimens to observe and must determine whether the
specimens are living or nonliving by observing them and applying the characteristics of life.
http://digitalcommons.pace.edu/cgi/viewcontent.cgi?article=1001&context=middle_sci
Overcoming Misconceptions
Be sure to distinguish between the terms living thing and alive. Something that is alive is currently living. Generally,
it refers to a whole organism. Living things make up a broader category that includes things that were once alive (but
are now dead) as well as parts of things that are or once were alive. Discuss the following examples with students,
and ask them to categorize them as living or nonliving things.
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Fallen leaves on a forest floor (Living things: they are now dead but were once parts of a living thing.)
Your hair or fingernails (Living things: they consist of dead cells but they are parts of a living thing.)
Your ancestors from long ago (Living things: they are living things that are now dead.)
Cotton fabric or wooden floor (Nonliving things: they come from living things that are now dead but they have
also been modified so they are no longer living things.)
Reinforce and Review
Lesson Worksheets
Copy and distribute the Lesson 2.1 worksheets in CK-12 MS Life Science Workbook. Ask students to complete the
worksheets alone or in pairs to reinforce lesson content.
Lesson Review Questions
Have students answer the Review Questions at the end of Lesson 2.1 in CK-12 MS Life Science Flexbook. Answers
are provided below.
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List five characteristics of living things.
Describe cells.
What is energy? How do organisms use energy?
Describe a response to an environmental stimulus that might save your life.
Discuss the role of reproduction in life.
Explain why having a fever when you are sick disrupts your body’s homeostasis.
Lesson Quiz
Check students’ mastery of the lesson with Lesson 2.1 Quiz in CK-12 MS Life Science Assessments.
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Points to Consider
In this lesson, you read that all living things consist of one or more cells.
• What are cells made of?
• Is there any matter that is smaller than a cell?
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