1. What types of identifiers do we have?
Points to Ponder
A natural disaster strikes. Families are separated. How can they be reunited?
If a body is found and the person cannot be identified by looks, how can we identify them?
What types of identifiers do we have?

2. DNA- skin, sperm, saliva, blood Fingerprinting Teeth
A natural disaster strikes. Families are separated. How can they be reunited?
If a body is found and the person cannot be identified by looks, how can we identify them?
What types of identifiers do we have?
DNA- skin, sperm, saliva, blood
Fingerprinting
Teeth

3. Sydney Leslie Goodwin 1910-1912
Died in the sinking of the RMS Titanic
Known as “The Unknown Child”
The Goodwins and their 6 children were third class passengers and all perished
Finally identified in 2007 using DNA

4. KEY CONCEPT Biotechnology relies on cutting DNA at specific places.
Baby 81 was rescued after the 2004 Indian Ocean tsunami. He was reunited with his parents by using DNA fingerprinting technology

5. Biotechnology allows us to
Produce transgenic organisms
Clone
Study diseases and evolution
Produce medical treatments for people with illnesses

6. DNA cannot be picked up and rearranged by hand
Therefore, scientists must be able to work with DNA without being able to see it, or handle it directly

7. Scientists use several techniques to manipulate DNA.
Chemicals, computers, and bacteria are used to work with DNA.
Scientists use these tools in genetics research and biotechnology.

8. Restriction enzymes act as “scissors” by cutting DNA
allow scientists to more easily study and manipulate genes
cut DNA at a specific nucleotide sequence called a restriction site
DNA
Restriction enzyme

9. Different restriction enzymes cut DNA in different ways.
each enzyme has a different restriction site

10. some cut straight across and leave “blunt ends”
some make staggered cuts and leave “sticky ends”
Sticky ends

11. Between what nucleotides does this restriction enzyme cut between?
T and C or C and T

12. ATTACGACCTAGGACG How many fragments are produced?
Restriction enzyme: cuts between T and A
ATTACGACCTAGGACG
How many fragments are produced?
Are all the fragments the same length?
Please organize the fragments from biggest to smallest.
How many nucleotides in each segment when organized?

13. ATTACGACCTAGGACG How many fragments are produced? 3
Restriction enzyme: cuts between T and A
ATTACGACCTAGGACG
How many fragments are produced? 3
Are all the fragments the same length? No
Please organize the fragments from biggest to smallest. ACGACCT/AGGACG/ATT
How many nucleotides in each segment when organized? 7, 6, 3

14. After DNA has been cut, several different things can be done with it
The gene can be studied
The gene can be placed in another organism
But first, the DNA fragments have to be separated from one another
Sorted according to their size

15. Gel electrophoresis is used to separate DNA fragments by size.
A DNA sample is cut with restriction enzymes.
Electrical current pulls DNA fragments through a gel.

16. Smaller fragments move faster and travel farther than larger fragments.
Fragments of different sizes appear as bands on the gel.

17. A restriction map shows the lengths of DNA fragments between restriction sites.
only indicate size, not DNA sequence
useful in genetic engineering
used to study mutations

18. ATTACGACCTAGGACG Restriction enzyme: cuts between T and A
Please organize the fragments from biggest to smallest.
ACGACCT (7)
AGGACG (6)
ATT (3)

19. - - - - + Please organize the fragments from biggest to smallest.
ACGACCT (7)
AGGACG (6)
ATT (3) 10 9 8 7 6 5 4 3 2 1 - - - +