Science Assessment ~ Ideas ~ All living things are composed of one or more cells.

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

Sub-Ideas
Items & Student Performance
Misconceptions
NGSS

Students are expected to know that:

All organisms, including animals, plants, fungi, and microorganisms, are made up of cells.
Cells vary in size, shape, and specialized functions.
Most cells are so small that their details can be seen only with a microscope.
Living things can be made of just one cell to many millions of cells.
Some organisms are made of many types of cells and many of each type.
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.
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:

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

Percent of students answering correctly (click on the item ID number to view the item and additional data)
Item ID Number	Knowledge Being Assessed	Grades 6–8	Grades 9–12
CE101004	Both the brain and muscles of the body are made of cells.	67%	72%
CE103003	Both the flowers and stems of plants are made of cells.	63%	72%
CE033002	When looking through a microscope at leaf and root samples, one would see that both are made of cells.	63%	70%
CE102003	Both the leaves and roots of plants are made of cells.	61%	71%
CE053002	Different cells can have different sizes and shapes.	57%	63%
CE100004	Both the skin and the lungs of the body are made of cells.	55%	64%
CE010001	Different organisms range in the number of cells they have, from only one cell to many millions.	52%	60%
CE128001	Different organisms range in the number of cells they have, from only one cell to many millions.	48%	56%

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.

NGSS Statements
Code	Statement
LS1.A MS	All living things are made up of cells, which is the smallest unit that can be said to be alive. An organism may consist of one single cell (unicellular) or many different numbers and types of cells (multicellular).
LS1.A MS	In multicellular organisms, the body is a system of multiple interacting subsystems. These subsystems are groups of cells that work together to form tissues and organs that are specialized for particular body functions.