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Name_____________________________
Date/Class Period____________________
GENE REGULATION/CELL DIFFERENTIATION ACTIVITY (TEKS 6D, 5C)
Notice the “STEM CELL DNA” sequence below. Recall that stem cells are unspecialized cells;
they can become any type of cell (including bone, muscle, nerve, epithelial, blood, etc.). As a
cell becomes specialized, however, some genes are turned on (“expressed”), and some genes
are turned off. Your job is to investigate the expressed DNA, transcribe it to mRNA, translate it
into a protein, and then use the information included on the next page to determine to which
protein / specialized cell the expressed gene belongs. In the specialized cell DNA sequences, the
expressed genes are bold. Good luck, scientist! 
STEM CELL DNA (unspecialized):
TAC – GCC – AAT – ACT – TAC – CTA – ATA – ACG – TAC – GGG – ACC – ATT – TAC – CGG – CAG – ATC
SPECIALIZED CELL DNA 1:
TAC – GCC – AAT – ACT – TAC – CTA – ATA – ACG – TAC – GGG – ACC – ATT – TAC – CGG – CAG – ATC
mRNA PRODUCED BY TRANSCRIPTION:
AMINO ACIDS:
PROTEIN/CELL TYPE:
________________________________
__________________
____________/____________
SPECIALIZED CELL DNA 2:
TAC – GCC – AAT – ACT – TAC – CTA – ATA – ACG – TAC – GGG – ACC – ATT – TAC – CGG – CAG – ATC
mRNA PRODUCED BY TRANSCRIPTION:
AMINO ACIDS:
PROTEIN/CELL TYPE:
_______________________________
__________________
____________/____________
SPECIALIZED CELL DNA 3:
TAC – GCC – AAT – ACT – TAC – CTA – ATA – ACG – TAC – GGG – ACC – ATT – TAC – CGG – CAG – ATC
mRNA PRODUCED BY TRANSCRIPTION:
AMINO ACIDS:
PROTEIN/CELL TYPE:
_______________________________
__________________
____________/____________
SPECIALIZED CELL DNA 4:
TAC – GCC – AAT – ACT – TAC – CTA – ATA – ATT – TAC – GGG – ACC – ATT – TAC – CGG – CAG – ATC
mRNA PRODUCED BY TRANSCRIPTION:
AMINO ACIDS:
PROTEIN/CELL TYPE:
_______________________________
__________________
____________/____________
Name_____________________________
Date/Class Period____________________
PROTEIN & SPECIALIZED CELL INFORMATION
Myosin is a protein
involved in muscular
contraction (muscle
cells). In this activity,
myosin is represented
by the amino acids
methionine,
asparagine, & tyrosine.
Insulin is produced by
the pancreas and is
involved in a cell’s
ability to absorb
glucose, which your
mitochondria need for
cellular respiration.
Insulin contains the
amino acids
methionine, alanine, &
valine.
Hemoglobin is a protein
found in red blood cells
that is responsible for
carrying oxygen
throughout the body. In
this activity,
hemoglobin is
represented by the
amino acids
methionine, arginine, &
leucine.
Myelin is found in nerve
cells. It creates a coating
around nerve axons,
called a myelin sheath,
which acts as an insulator
and speeds up nerve
impulses. Its amino acids
are methionine, proline,
& tryptophan (trp).
Name_____________________________
Date/Class Period____________________
Conclusion Questions:
1.
Explain the difference between a stem cell and a specialized cell.
2.
What is different about the DNA of a specialized cell when compared to a stem cell?
3.
Explain what it means for a gene to be “expressed.”
4.
Are the proteins of one specialized cell made in specialized cells of a different type? (For
example, are blood cell proteins made in nerve cells, etc) Why or why not?
5.
What does it mean to say that genes are “regulated?”
6.
What would a scientist have to do in order to turn a specialized cell back into a stem cell?
7. Cell differentiation is critical during embryonic development. The process of cell differentiation
results in the production of many types of cells, including germ, somatic, and stem cells. Cell
differentiation is most directly regulated by—
A ATP
B DNA
C lipids
D sugars
Name_____________________________
KEY
1. MET-ARG-LEU-STOP (Hemoglobin/Blood cell)
2. MET-ALA-VAL-STOP (Insulin/Pancreatic Beta cell)
3. MET-PRO-TRP-STOP (Myelin/Nerve cell)
4. MET-ASP-TYR-STOP (Myosin/Muscle cell)
Date/Class Period____________________