Science Assessment ~ Ideas ~ "Theme 1" Genetic information is encoded in DNA molecules.

Key Idea: Genetic information is encoded in DNA molecules.

Sub-Ideas
Items & Student Performance
Misconceptions
NGSS

Students are expected to know that:

Genetic (hereditary) information is the set of instructions that specifies the physical and behavioral characteristics of organisms.
Genetic information is found in all living organisms.
The instructions that specify the physical and behavioral characteristics of organisms are coded in DNA molecules (not in protein, carbohydrate, or fat molecules).
DNA molecules are made up of four different types of subunits called nucleotides that are linked together in long chains.
The sequence of subunits in a DNA molecule is what encodes the genetic information.
DNA is packaged as chromosomes in the cells of organisms.
Each chromosome is made of a single DNA molecule.
A gene is one or more segments of a DNA molecule that contributes to one or more particular physical and behavioral characteristics.
Each chromosome is made of many different genes.

Boundaries:

Students are not expected to know the names of the nucleotide subunits.
Students are not expected to know that DNA is bound to histones and other proteins in chromosomes.

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 (Control)	Post-Test (Treatment)	Select This Item for My Item Bank
RH045001	DNA molecules are found in humans, dogs, and trees.	65%	66%	82%
RH024007	Both an organism's physical characteristics and the function of the organism's cells could be affected by the information in the organism's DNA molecules (no specific organism identified).	61%	64%	73%

Frequency of selecting a misconception
Misconception ID Number	Student Misconception	Pre-Test	Post-Test (Control)	Post-Test (Treatment)
RHM048	Only animals have DNA; plants and mushrooms do not have DNA (Banet & Ayuso, 2000).	29%	31%	15%
RHM083	The information in the DNA molecules of an organism does not affect the functions of an organism's cells (AAAS Project 2061, n.d.).	12%	12%	9%
RHM105	There are some types of organisms that do not have DNA (See Lewis & Wood-Robinson, 2000; Banet & Ayuso, 2000).	12%	11%	6%
RHM084	The information in the DNA molecules of an organism does not affect the physical characteristics of the organism (AAAS Project 2061, n.d.).	10%	8%	7%

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 HS	All cells contain genetic information in the form of DNA molecules. Genes are regions in the DNA that contain the instructions that code for the formation of proteins, which carry out most of the work of cells.
LS3.A MS	Genes are located in the chromosomes of cells, with each chromosome pair containing two variants of each of many distinct genes. Each distinct gene chiefly controls the production of specific proteins, which in turn affects the traits of the individual. Changes (mutations) to genes can result in changes to proteins, which can affect the structures and functions of the organism and thereby change traits.
LS3.A HS	Each chromosome consists of a single very long DNA molecule, and each gene on the chromosome is a particular segment of that DNA. The instructions for forming species' characteristics are carried in DNA. All cells in an organism have the same genetic content, but the genes used (expressed) by the cell may be regulated in different ways. Not all DNA codes for a protein; some segments of DNA are involved in regulatory or structural functions, and some have no as-yet known function.