A readily available resource to create a model for the study of DNA is the human
hand. Students can recognize how structure and function of nucleotides determine
structure and function of the DNA molecule by labeling parts of a gloved hand
with the parts of a DNA molecule.
Key Words: Adenine; concentration; cytosine; deoxyribose; guanine; inverted;
purines; pyrimidines; thymine.
Modeling activities are at the forefront of science education in
American schools today (Bryce et al., 2016). Modeling enables
students to create, analyze, and demonstrate the dynamic inner
workings of a concept or object, thereby offering evidence of a thorough understanding of it (Louca & Zacharia, 2012). Many teachers
at the middle and high school levels devote a sizable portion of their
curriculum toward construction of models to exhibit structure and
function of DNA (Robertson, 2016). I have developed a DNA model
that can supplement some of the DNA modeling materials like
marshmallows, toothpicks, and construction paper. It’s a “Handy
DNA Nucleotide Model,” using the human hand.
Handy DNA Nucleotide Model
A portion of a DNA molecule (Figure 1) can be broken down into indi-
vidual DNA nucleotides (Figure 2) for analysis. A DNA nucleotide is
drawn on a glove with markers to serve as a model (Figure 3).
Students will mark seven locations on the top and bottom surfaces
of the gloved hand to represent the parts of a DNA nucleotide, exclud-
ing the nitrogen base. Five of the locations are comprised of an oxygen
atom and four carbon atoms of the deoxyribose ring structure on the
palm of the glove and one carbon bonded to the exterior of the ring
located on the thumb at the sixth location. The last location is a phos-
phate ion, an encircled P, bonded to the fifth carbon atom. The
phophate ion enables bonding to a carbon on an adjacent nucleotide.
These phosphate-to-carbon bonds up and down the length of the mol-
ecule contribute to making the two “DNA backbones” of the DNA mol-
ecule. The pyrimidine nitrogen bases are cytosine (C) and thymine (T),
and the purine nitrogen bases are adenine (A) and guanine (G).
In Figure 4, the forefinger is a model for a pyrimidine base, either C
or T, because the pyrimidine bases are shorter one-ringed molecules like
the shorter forefinger. The second finger represents a purine base, either
A or G, because the purines are longer two-ringed molecules like the
longer second finger. (Compare the sizes of nitrogen bases in Figure 1.)
Separate the class into two groups. Instruct the groups to mark
their gloves as follows:
– Mark the forefinger of the left glove with a C and second finger with
– Mark the forefinger of the right glove with a T and the second
finger with a G.
– Mark the forefinger of the left glove with a T and the second finger
with a G.
– Mark the forefinger of the right glove with a C and the second
finger with an A.
Modeling DNA Nucleotides &
Using both gloved hands, one palm up and the other inverted (palm
down) and allowing the tip of the forefinger or the second finger
of one gloved hand to touch the tip of the second finger or forefinger, respectively, of the other gloved hand, a model for the bonding
pattern of the DNA nucleotides is created. For example, with one
palm up and the other palm down, the student could touch the
forefinger of the left glove with the second finger of the right glove,
thus modeling a C-G or T-A bond (Figure 5). The thumbs of both
The American Biology Teacher, Vol. 81, No. 3, pp. 193–196, ISSN 0002-7685, electronic ISSN 1938-4211. © 2019 National Association of Biology Teachers. All rights
reserved. Please direct all requests for permission to photocopy or reproduce article content through the University of California Press’s Reprints and Permissions web page,
www.ucpress.edu/journals.php?p=reprints. DOI: https://doi.org/10.1525/abt.2019.81.3.193.
THE AMERICAN BIOLOGY TEACHER HANDY DNA NUCLEOTIDE MODEL
TIPS, TRICKS &
Handy DNA Nucleotide Model
• JAMES MIDDLETON