Key Idea: All living things are composed of one or more cells.

Students are expected to know that:

  1. All organisms, including animals, plants, fungi, and microorganisms, are made up of cells.
  2. Cells vary in size, shape, and specialized functions.
  3. Most cells are so small that their details can be seen only with a microscope.
  4. Living things can be made of just one cell to many millions of cells.
  5. Some organisms are made of many types of cells and many of each type.
  6. In single-celled organisms such as bacteria, the single cell carries out all of the functions needed for the organism to stay alive; in organisms made of many cells, individual cells work together with (depend on) other cells to carry out their essential life functions.
  7. In multicellular organisms, the structures that make up those organisms (including brain, muscles, skin, and lungs in animals, and stems and flowers in plants) are made up of cells.

Boundaries:

  1. Students are not expected to know the terms "prokaryote" or "eukaryote" or the differences between these types of cells.
  2. Items will not test students’ knowledge of fungi.
Frequency of selecting a misconception

Misconception
ID Number

Student Misconception

Grades
6–8

Grades
9–12

CEM001

All cells are the same size and shape, i.e., there is a generic cell (AAAS Project 2061, n.d.).

43%

37%

CEM005

There are no single-celled organisms (AAAS Project 2061, n.d.).

39%

30%

CEM003

Some living parts of organisms are not made of cells (AAAS Project 2061, n.d.).

36%

29%

CEM004

Plants are not made of cells (AAAS Project 2061, n.d.).

7%

5%

Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.