Cells from the same individual can have different appearances despite having identical DNA because cells can selectively express different genes. Early in development, stem cells differentiate into specialized cell types by activating different sets of genes through gene regulation. Gene expression involves using DNA as a template to produce mRNA and then translate it into specific proteins. Different cell types produce different proteins by expressing only the genes required for their function.

1. 1-10-17 Warm up
Matching
1. DNA
2. Protein
3. Nucleotide
4. Amino acid
A. The monomers (building
blocks) of nucleic acids
B. The product of the cell,
coded for by genes on the
DNA
C. Made up of genes; found in
the nucleus
D. The monomers (building
blocks) of proteins; coded
for by codons in the RNA.
C B A DC B A D

2. https://www.youtube.com/watch?

3. Gene Expression

4. Liver Cells
Cartilage Cells
Red Blood Cells
Eye Cells
What makes cells from the same
individual look different?
Do they contain different DNA?

5. If the DNA in every cell is the same, how is it
possible to have different cell types?
Junior Beck
has over 200
cell types
and loves
posing for
Snaps.

6. Remember…
1. Why is the nucleus of the cell
important?
2. Humans body cells have a total of ____
individual chromosomes or ___ pairs of
chromosomes.
3. Genes code for ______ which are
assembled on the ________
Contain DNA, directs cells activities
46
23
proteins
ribosomes
Cats have 38
chromosomes
(19 pairs)

7. Objective
Explain how cells are different due to
differences in gene expression

8. Activity Prep
CUT out the
karyotypes
PASTE 1 karyotype
in the zygote to
show what
chromosomes the
man inherited from
his parents.

9. • Multicellular organisms require groups of
specialized cells in order to function
properly
• What are some different cell types in an
animal or a plant?

10. Sperm + Ovum  zygote
fertilization
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zygote
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Draw this

11. So…
Cells in the embryo begin as stem
cells
After about 7-10 days the cells begin to
differentiate into different cell types
Muscle cells
Nerve cells
Bone cells
Skin cells…
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All the same

12. • So if every cell in our body has the
same genetic code, how do they become
different from each other?

13. Practice
GLUE 1 karyotype
into each box to
represent that every
cell in our body has
the same genetic
code

14. CFU: Cell Differentiation Video
random selection/ complete sentence
1. How is it possible to develop great
diversity of different types of cells in
any multi-cellular body?
2. The body has approximately _____
cell types.
3. Stem cells can develop into
______kinds of cells.
4. ____ control the differences among
cells.
5. All of these complicated processes are
a part of the ___ of each organism.
Word bank:
•Different
•Genes
•Genetic code
•260
•Gene regulation

15. Cell Differentiation: 1:30 Stop at Human Genome

16. CFU: Cell Differentiation Video
random selection/ complete sentence
1. How is it possible to develop great
diversity of different types of cells in
any multi-cellular body?
2. The body has approximately _____
cell types.
3. Stem cells can develop into
______kinds of cells.
4. ____ control the differences among
cells.
5. All of these complicated processes are
a part of the ___ of each organism.
Word bank:
•Different
•Genes
•Genetic code
•260
•Gene regulation

17. Different cell types EXPRESS
different genes in the DNA code
Renin is
produced by
kidney cells
Keratin is
produced by
cells skin
Myosin is
produced by
muscle cells
Hemoglobin is
produced by the
red blood cells
Amylase is
produced by
saliva gland
cells
Words in green indicate proteins

18. Stomach
cells
produce the
protein
PEPSIN
Kidney cells
produce
RENIN
Eye cells
produce the
protein
CRYSTALLIN
Muscle cells
produce the
protein
ACTIN
Intestinal
cells
produce the
protein
TRYPSIN
Now write in the
protein name and
highlight the
chromosome that
has the gene for
that protein

19. actin
crystallin
pepsin
renin
trypsin

20. Gene expression = the DNA is used to
make mRNA which is then used to build
the protein that gene codes for
DNA mRNA
amino
acids
protein

21. Recap
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1. Cells start out the
same
2. Early in development
they differentiate
into different cell
types
3. Different cells
express different genes

22. How do cells know which
genes to express?
• Heterochromatin – DNA that is not
expressed is packed very tightly
• Euchromatin – DNA that will be expressed
is packaged more loosely

23. So…
What makes cells from the same
individual look different?
Do different cells contain different DNA?
If the DNA in every cell is the same, how
is it possible to have different cell types?
Explain how this cat can have
hundreds of different cell
types that all contain the
same DNA .
This is
Malfoy Beck

24. DNA replication model
 Work with a partner to:
 Create a model of DNA
during replication
 Include:
 Deoxyribose/phosphate
backbone
 A-T and G-C
 Semiconservative nature of
replication
 Original parent DNA
 New DNA