1. BIOLOGY NOTES GENETICS PART 6 PAGES 230-238

2. Standards:
_____ Describe the basic processes of DNA replication and how it relates to transmission and conservation of genetic information
_____ Evaluate the impact of biotechnology on the individual, society, and the environment including medical and ethical issues
5.9
5.12

3. Essential Questions: 1. Why is the sequence of nucleotides on DNA
molecules so important?

4. Deoxyribose Nucleic Acid (DNA) = the genetic material that composes all ______ organisms
nucleic acids are highly complex _________ made up of smaller monomer subunits called ____________
nucleotide = monomer of nucleic acids composed of a 5-carbon ______, a phosphate group, and a nitrogenous ______
living
polymers
nucleotides
sugar
base

6. DIAGRAM:

7. Deoxyribose is the name of the ______ in DNA
DNA has 4 possible nitrogenous bases:
1. Adenine (A)
2. Thymine (T)
3. Cytosine (C)
4. Guanine (G)
sugar

8. purine = a nitrogenous base with __ rings
e.g.
pyrimidine = a nitrogenous base with __ ring 2
adenine, guanine 1
thymine, cytosine

9. A. DNA Structure
In DNA, nucleotides join together to form ___ long chains which together compose the polymeric nucleic acid
the chains of nucleotides in DNA are joined by _________ bonds between the bases resulting in a _______ shape
the chains twist together to form a _______ helix 2
hydrogen
ladder
double

12. the double helix shape was first discovered in 1953 by James _______ and Francis ______
Watson
Crick

13. Erwin ________ discovered that specific bases will pair together in DNA. This became known as Chargaff’s rules and later the principle of base pairing.
base pairing principle = principle that hydrogen bonds in _____ can only form between adenine and ________ or guanine and _________
Chargaff
DNA
thymine
cytosine

14. DIAGRAM:

15. B. DNA Sequence
How can organisms be different from each other if their genetic material is made of the same molecules (DNA)? **WORD JUMBLE**
Answer: the _________ of ___________ in the DNA strands of organisms is _________
The __________ of nucleotides forms the unique genetic information of an organism. The more closely related two organisms are, the more _____ the order of nucleotides in their DNA will be.
sequence
nucleotides
different
sequence
alike

16. Human Genome Project = research project that led scientists to discover the exact _________ of nucleotide bases for the human ________
begun in _____ and completed in _____
documented the exact nucleotide sequence for over __ billion base pairings
sequence
species
1990
2003 3

17. C. DNA vs. Chromosome vs. Chromatin All cells contain DNA
prokaryotic DNA is contained in the __________ of the cell
eukaryotic DNA is contained in the _______ of the cell
cytoplasm
nucleus

18. DNA is extremely _____. The nucleus of each human cell contains more than 1 ______ of DNA. How does it fit???
histones = proteins inside of the nucleus that _____ wraps itself around tightly
nucleosomes = the beadlike structure formed from several _________ wrapped together in _____
when nucleosome are supercoiled but not organized in structure, __________ is present
long
meter
DNA
histones
DNA
chromatin

19. when nucleosomes are supercoiled into organized structures that are tightly packed, _____________ are present
chromosomes

21. D. DNA Replication
During cell __________, exact copies of cells are made including all _______ information. During cell ________, copies of gametes are made which also include copying of genetic information.
DNA replication = the production of a genetically identical copy of DNA made prior to cell ________
made during the ___ phase of interphase
replication
genetic
meiosis
division S
(synthesis)

22. without replication, a species could not _______ and individuals could not successfully _____ and reproduce
STEPS OF DNA REPLICATION:
The double helix ________ and _________ break the hydrogen bonds holding together the paired bases. This is known as ___________ the DNA.
replication fork = the point at which the 2 chains of DNA are separated
survive
grow
unwinds
enzymes
“unzipping”
** helicases are enzymes that unwind**

24. 2. Free floating ___________ in the nucleus bond to the single strand by _____ pairing. The added bases are known as ______________ bases and the new strands are _______________________ to the original strands.
DNA polymerase = the principle enzyme involved in DNA replication because it bonds the free ______ to the original bases and __________ each new DNA strand.
nucleotides
base
complementary
complementary (mates)
bases
proofreads

26. 3. Replication continues until all of the DNA in all of the _____________ of the cell have been copied. The results are __ copies of the organism’s genetic material.
each new copy consists of ___ original copy of DNA and ____ new, complementary strand.
chromosomes 2 1 1

28. QUESTION: What would be the complementary base sequence of DNA for TACGTTC?
ANSWER: ______________________________________ A T G C A A G