Science Assessment ~ Ideas ~ Multicellular organisms have a hierarchical structural organization, in which any one system is made up of numerous parts and is itself a component of the next level. The systems that make up an organism’s body work together to carry out functions needed for growth and survival.

Key Idea: Multicellular organisms have a hierarchical structural organization, in which any one system is made up of numerous parts and is itself a component of the next level. The systems that make up an organism’s body work together to carry out functions needed for growth and survival.

Sub-Ideas
Items & Student Performance
Misconceptions
NGSS

Students are expected to know that:

Multicellular organisms need a way to obtain oxygen for cellular respiration and eliminate carbon dioxide produced. The respiratory system, including the lungs, take in air rich in oxygen, which passes into blood vessels, and gives off air rich in carbon dioxide that has come from blood vessels.
Multicellular organisms need a way to transport molecules from one body system to another. The circulatory system (including a heart that pumps blood and vessels of various diameters including capillaries) transports the reactants and products of various chemical reactions in response to changes in the body’s needs.
Multicellular organisms need energy to move and grow. At the macroscopic level, muscle contraction moves bones.
Systems of specialized cells within organisms help them perform the essential functions of life, which involve chemical reactions that take place between different types of molecules, such as water, proteins, carbohydrates, lipids, and nucleic acids.
Groups of specialized cells (tissues) use proteins to carry out functions that are essential to the organism.
The large carbon-based molecules that make up an animal’s food must be broken down into smaller molecules that can be transported to cells that use them. The chemical reactions involved occur in the digestive system.

Boundaries:

The body systems and parts of those systems that are mentioned above were selected to illustrate the hierarchical organization and to enable students to make sense of phenomena involving biological growth and motion. Students are not expected to know all the parts of all the eleven different body systems.

Percent of students answering correctly (click on the item ID number to view the item and additional data)
Item ID Number	Knowledge Being Assessed	Pre-Test	Post-Test
EB080001	In order of increasing size, the components of the circulatory system are carbon atom, amino acid, protein, red blood cell, blood vessel.	40%	34%
EB069001	Protein, carbohydrate, and fat molecules from food are broken down in the digestive system into smaller molecules (subunits) that can enter the blood stream and be distributed throughout the body.	33%	41%
EB073001	After eating a meal that is high in protein, the level of amino acids in blood vessels flowing toward the small intestine is lower than in blood vessels flowing away from the small intestine.	30%	35%
EB070001	Amino acids but not proteins pass from the digestive system to the circulatory system.	26%	33%
EB074001	After eating a meal, the level of glucose is higher in blood flowing away from the small intestine than toward it, whereas after an overnight fast the level of glucose is low in both blood flowing toward and flowing away from the small intestine.	24%	33%

Frequency of selecting a misconception
Misconception ID Number	Student Misconception	Pre-Test	Post-Test
AMM068	Cells are smaller than atoms (Tretter et al., 2006).	17%	17%

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	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.
LS1.A HS	Multicellular organisms have a hierarchical structural organization, in which any one system is made up of numerous parts and is itself a component of the next level.