Characteristics of Life
Before using this lesson plan, be sure that you have first utilized the first lesson plan in this series, which introduces the characteristics of life. Students need to know this material before they can explore the levels of biological organization as these levels are a part of the characteristics of life.
Please review the following characteristics of life with your students.
- Biological organization
- Acquiring materials and energy
- Response to stimuli
- Growth and development
Instruct students that this particular lesson plan will place focus on the first characteristic of life, biological organization.
Levels of Biological Organization
Teachers, the term "levels of biological organization" may confuse some students. It would be a good idea to begin this portion of the lesson plan by asking students what they think the term means. Allow students to express what they think, then let them know that biological organization is simply by the way of classifying the physical basics of a living thing from the smallest to the largest. You should also let them know that not all living things will have all the levels of organization. Review the following levels of organization with your students.
These levels are listed from the smallest to the largest.
- organ systems
To help students to understand what these levels of biological organization are, do the activity listed below that will give them specific examples of these levels.
Ask students to draw a pyramid in their notebooks. Draw a pyramid on the board. Explain to students that the smaller levels of biological organization work together to create the larger levels until a complete organism is created. Explain that you are going to be beginning at the bottom of the pyramid to demonstrate this event. Using the list below, ask students to write the examples in their pyramids for each level of biological organization
- On the lowest level, students should write "atoms". Explain to students that 98% of the body weight of organisms is made up of only six elements. These elements are listed in the periodic table with the measurements given based on one atom. Have the students write these six elements as examples of atoms in their pyramid; carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur.
- On the next level up, have students write the word "molecules". Explain that in living things, atoms join to form molecules. In humans, one of the molecules that is formed is called DNA or Deoxyribonucleic Acid. Ask students to write this next to the word molecules on their pyramid.
- On the third level from the bottom, students should write "cells". Let students know that a cell is the smallest structural and functional unit of an organism. Some examples of cells are nerve cells and brain cells. Ask students to write these on their pyramids.
- The next level up is tissues. Ask students to write this on their pyramid. Explain that tissue is made up of similar cells that combine to perform a function. Some examples of tissues are nerve tissue and brain tissue. Ask students to write these on their pyramid. (These particular ones were chosen to assist students in seeing the correlation between cells and tissues.)
- Moving up a level, we come to organs. Ask students the write this word in the appropriate place on their pyramid. Explain that just as similar cells combine to make tissues, so do similar tissues combine to make organs. Some examples that students may write on their pyramid are the brain, skin, stomach etc.
- On the next level up ask students to write "organ systems". Explain that organ systems are the result of several organs working together to perform a function. Some examples that students may write on their pyramid are the digestive system, nervous system and cardiovascular system.
- Finally, at the top of the pyramid, the organ systems work together to form an organism. In this particular activity we have been discussing the biological organization of humans. Once students write the word "organism" at the top of their pyramid, ask them to write "human" next to it.
A good way to round off the lesson plan and make sure students understand how each level works together is to hold a discussion with the students. During the discussion, ask students if humans in particular would be able to function if any of these systems were absent. Given the advances of modern science, this may raise some interesting debates and allow students to see how science works in conjunction with nature.
This post is part of the series: Characteristics of Life Series
- Introducing the Characteristics of Life
- Science Lesson Plan: Biological Organization
- Lesson Plan: Reproduction in Biology
- Lesson Plan: Homeostasis as a Characteristic of Life
- Biology Lesson Plan: How Animals & Organisms Adapt