2. The most astonishing thing about
life is…
Every single living thing on the face of
the earth is made of the same 20 amino
acids organized and directed by
variations of the same molecule, DNA.

4. Life Science CONTENT STANDARD C:
 Asa result of their activities in
grades 9-12, all students should
develop understanding of
1. The cell
2. Molecular basis of heredity
3. Biological evolution

5. THE CELL
Cells store and use information to guide their
functions.
The genetic information stored in DNA is used
to direct the synthesis of the thousands of
proteins that each cell requires.

6. If just one of the 10 to 100 trillion cells in your body were the
size of a baseball park, the average bacterium would be the size
of a pitcher’s mound, and the average virus would be the size of
a baseball.

7. E.COLI

8. THE CELL
Cell functions are regulated. Regulation
occurs:
through changes in the activity of the
functions performed by proteins
through the selective expression of
individual genes.
This regulation allows cells to respond to
their environment and to control and
coordinate cell growth and division.

9. THE DNA MODEL

10. DNA model alone can be used to show (or to allow for the
discovery of) all the features of DNA that are important in
grades 5-12:
That DNA is made up of four different nucleotides

11. The nucleotide parts: sugar, phosphate, and
base

12. DNA model alone can be used to show (or
to allow for the discovery of)
That the double helical structure: derives from
the shapes and bonding of the nucleotides ,
and occurs only when two DNA chains join
base to base and are antiparallel
QuickTime™ and a
decompressor
are needed to see this picture.

13. Replication of DNA
by strand separation
and laying down of
new nucleotides along
the separated strands.

14. DNA model alone can be used to show (or
to allow for the discovery of) …
The weak bonds that form between complementary
bases
The strong bonds that form between the sugar and
phosphate molecules in the DNA backbone
That the helices unzip readily due to the weak bonds
between complementary bases while the strands
remain intact due to the strong bonds of the
backbone.
The Energetics of bond breaking and bond formation

15. DNA model can be used to show (or to allow for the
discovery of)…
Transcription of
DNA message
into an RNA
copy (mRNA
or messenger
RNA)

16. Its coding function - how sequences of nucleotides
can act as a code for sequences of amino acids in
protein molecules
Each combination of three
nucleotides (A G C or U)
is the code for a particular
amino acid.
Either UUU, or UUC,
is the code for the top
left amino acid, phenyl-
alanine

17. SCALE
It can be used to dramatize scale: e.g. if all the DNA in
only one human cell were stretched out in one long
strand it would be about 1 meter long. If the same
amount were represented by the model and similarly
stretched out, it would be about 149,668 km (or 93,000
miles) long.

18. The antiparallel directionality of the
complementary DNA strands
QuickTime™ and a
decompressor
are needed to see this picture.

19. Mutation - how information is encoded in DNA
molecules and how it is modified by mutation: how its
language changes – evolves – over the generations

20. NUCLEOTIDE TO GENOME

21. The model can be used to demonstrate or elicit
several of the Basic Science Process Skills
 Grades 5-8
 OBSERVING
 USING SPACE-TIME RELATIONSHIPS
 Symmetry, mirroring, describe directions, spatial arrangements
 MEASURING
 Estimation of size, scale
 COMMUNICATING
 PREDICTING
 Based on observations measurements and inferences about relationships
 INFERRING

22. THE INTEGRATED PROCESSES
 FORMULATING HYPOTHESES
 DEFINING OPERATIONALLY
 EXPERIMENTING