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	Grades 6–8	Grades 9–12
RH001001	DNA is the molecule that contains genetic information that is passed from parents to offspring.	94%	96%
RH045001	DNA molecules are found in humans, dogs, and trees.	42%	54%
RH026004	Both chromosomes and DNA molecules contain genetic information.	58%	72%
RH026001	Both genes and DNA molecules contain hereditary information.	59%	66%
RH014001	The genetic code is the sequence of subunits in a DNA molecule.	53%	70%
RH026003	Both chromosomes and DNA molecules contain hereditary information.	51%	63%
RH026002	Both genes and chromosomes contain hereditary information.	48%	62%
RH046001	DNA molecules are found in humans, butterflies, and trees.	46%	59%
RH024002	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).	45%	52%
RH024005	Both a bird's physical characteristics and its behaviors could be affected by the information in the bird's DNA molecules.	45%	50%
RH024003	Both a human's physical characteristics and its behaviors could be affected by the information in the DNA molecules in the human.	42%	50%
RH002003	Four different types of nucleotides are used to make DNA molecules, not one, two, or twenty.	40%	52%
RH002002	Four different types of nucleotides are used to make DNA molecules, not one, two, or twenty.	38%	61%
RH024006	Both an insect's physical characteristics and its behaviors could be affected by the information in the DNA molecules in the insect.	42%	49%
RH024004	Both a plant's physical characteristics and its behaviors could be affected by the information in the DNA molecules in the plant.	41%	48%
RH024001	Both an organism's physical characteristics and its behaviors could be affected by the information in the organism's DNA molecules (no specific organism identified).	42%	45%
RH040001	Nucleotides (not amino acids, proteins, or fatty acids) are the subunits that make up DNA molecules.	34%	44%
RH002001	Four different types of nucleotides are used to make DNA molecules, not one, two, or three.	28%	41%
RH041001	Each chromosome is made of a single DNA molecule.	26%	23%
RH027001	Genes are chemical sequences of nucleotides, not the actual expression of characteristics or traits.	15%	19%

Frequency of selecting a misconception
Misconception ID Number	Student Misconception	Grades 6–8	Grades 9–12
RHM045	Genes are traits (Marbach-Ad, 2001).	64%	57%
RHM008	A gene and the expression of the gene as a characteristic or trait are the same thing (Lewis & Kattman, 2004).	64%	57%
RHM093	The information in the DNA molecules of a plant does not affect the behaviors of the plant (AAAS Project 2061, n.d.).	46%	42%
RHM092	The information in the DNA molecules of an insect does not affect the behaviors of the insect (AAAS Project 2061, n.d.).	44%	40%
RHM105	There are some types of organisms that do not have DNA (See Lewis & Wood-Robinson, 2000; Banet & Ayuso, 2000).	56%	44%
RHM091	The information in the DNA molecules of a bird does not affect the behaviors of the bird (AAAS Project 2061, n.d.).	41%	39%
RHM085	The information in the DNA molecules of an organism does not affect the the organism's behaviors (AAAS Project 2061, n.d.).	40%	41%
RHM090	The information in the DNA molecules of a human does not affect the behaviors of the human (AAAS Project 2061, n.d.).	41%	39%
RHM097	Amino acids are the subunits that make up DNA (AAAS Project 2061, n.d.).	38%	34%
RHM095	Two types of nucleotides make up DNA molecules (AAAS Project 2061, n.d.).	35%	30%
RHM047	Each DNA molecule is made of more than one chromosome (Marbach-Ad, 2001).	31%	34%
RHM046	Each chromosome is made of more than one DNA molecule (AAAS Project 2061, n.d.).	31%	33%
RHM102	Chromosomes do not contain genetic/hereditary information (AAAS Project 2061, n.d.).	34%	24%
RHM048	Only animals have DNA; plants and mushrooms do not have DNA (Banet & Ayuso, 2000).	40%	30%
RHM088	The information in the DNA molecules of an insect does not affect the physical characteristics of the insect (AAAS Project 2061, n.d.).	28%	20%
RHM086	The information in the DNA molecules of a human does not affect the physical characteristics of the human (AAAS Project 2061, n.d.).	28%	17%
RHM089	The information in the DNA molecules of a plant does not affect the physical characteristics of the plant (AAAS Project 2061, n.d.).	26%	19%
RHM103	DNA molecules do not contain genetic/hereditary information (AAAS Project 2061, n.d.).	25%	20%
RHM096	Three types of nucleotides make up DNA molecules (AAAS Project 2061, n.d.).	25%	18%
RHM087	The information in the DNA molecules of a bird does not affect the physical characteristics of the bird (AAAS Project 2061, n.d.).	23%	18%
RHM094	The genetic code is the number of subunits in DNA molecules -- not the sequence (AAAS Project 2061, n.d.).	26%	14%
RHM104	Genes do not contain genetic/hereditary information (AAAS Project 2061, n.d.).	22%	16%
RHM098	Twenty types of nucleotides make up DNA molecules (AAAS Project 2061, n.d.).	16%	9%
RHM099	Genes are sequences of amino acids (AAAS Project 2061, n.d.).	12%	15%
RHM049	Only 'higher' animals have DNA; many invertebrates do not have DNA (Banet & Ayuso, 2000).	15%	10%
RHM007	Genes are proteins (Marbach-Ad, 2001).	9%	9%
RHM084	The information in the DNA molecules of an organism does not affect the physical characteristics of the organism (AAAS Project 2061, n.d.).	28%	23%
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.).	36%	34%

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.