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Biology DNA Unit HW Packet #1
Name ________________________________ Date ________ Hour _______
DUE: ______________________
Lab
Daisy
Chain
Nucleotide Completed
Analysis Completion
HW
Completion
____
____
_____
Genetics
Disorders
#5
______________
5 total
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DNA Daisy Chain and Analysis of Replication
Background:
DNA structure, once hypothesized by Watson and Crick, led directly to speculation
about the mechanisms of DNA’s storage of genetic material. The proposal of a two
stranded molecule with complementary (G-C,.A-T) bases strongly hinted at a
mechanism for replicating (copying) DNA. Today we will build a model of the
double helix. Analyze its replication and join our molecules together, 5’ end to 3’
end to build one large DNA molecule.
Procedure
Follow the instructions on the DNA Daisy Chain handout to cut out a template for
your model. Use this template and the folding instructions to cut out your own
DNA molecule. Be sure to color your bases the correct color.
A = red
T = yellow
G = green
C = blue
Phosphate = white
Deoxyribose Sugar = Orange
Template:
Orange
A, T, G or C
one color
White
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DNA Daisy Chain Cut-Out Questions
1. What are the three parts of a nucleotide?
a.
b.
c.
2. Which bases are connected?
3. How many total bases did you draw?
4. How many bases would there be in one human cell?
5. Where in the cell would these bases be stored?
6. In terms of DNA structure, what determines whether you have blue
eyes or brown eyes?
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DNA Homework
DNA is a polymer composed of many monomers. Think of monomers as the many boxcars
that are linked together to form a long train. Each train (polymer) is composed of
different cars (monomers) and is a different length. The monomers in DNA are the
nucleotides.
A nucleotide is joined to the next nucleotide in the chain by a phosphodiester bond. Each
nucleotide is in turn made up of the joining of a nitrogenous base, a pentose sugar and a
phosphate group.
1. Label the following cartoon of a nucleotide with these three parts: base, sugar,
and phosphate.
(Hint: Use your notes to help)
Many of these nucleotides can be hooked together to form a nucleic acid like
deoxyribonucleic acid (DNA) or ribonucleic acid (RNA).
2. Let us build a very short RNA molecule by joining three nucleotides together with
the bases: cytosine, guanine, and adenine. Draw your own bases using the model in
question one; replace the base with the three bases listed above. (First one included
DNA is a double stranded polymer. These two
strands run in an anti-parallel direction. The
force holding one strand to another is
hydrogen bonding between the bases. We can
use a simplified model to convey this complex
structure. A key rule to follow is that certain
bases are complementary, pairing together like
puzzle pieces, to build the ladder-like
structure of DNA. Adenine pairs with Thymine
(or Uracil in RNA) and Guanine pairs with
Cytosine. [A with T or U and G with C]
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DNA STRUCTURE (Use Text book - pg 228 – 233)
1. DNA is an abbreviation for
.
2. In the 1920’s, P.A. Levine showed that DNA is made of what 3 parts?
A.
B.
C.
3. There are 4 nitrogenous bases. Their full names are:
A.
B.
C.
D.
4. When a nitrogenous base, a sugar, and a phosphate group are put together, the
resulting molecule is called a
5. The sugar in DNA is named
.
__________
__________
.
6. While studying the chemical makeup of DNA, Erwin Chargaff found that the
nitrogen bases do not occur in equal proportions. Later, scientists used this
information to help determine the structure of DNA. How did this information
help determine the structure of DNA? (What did they figure must be true
about the nitrogen bases?)
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7. In 1953, two scientists determined the structure of DNA.
A. Who were these two scientists?
B. What scientific term describes DNA’s shape?
C. How many strands does DNA have?__________________________
D. Which nitrogen bases pair together?
1.
2.
8. How are the “rungs” of DNA held together?
9. How many base pairs are in a single human cell?
10. If the sequence of DNA is C T A C G T, the sequence of nucleotides on the
other strand of DNA would be
11. In your own words, describe the importance of DNA.
approximately 3 – 4 complete sentences.
6
.
Please write
GENETIC DISORDER RESEARCH PACKET PART V
My assigned genetic disorder is
Answer in complete sentences. Be sure to attach a copy of your references to
the homework packet.
GENETIC DISORDER PROJECT ASSIGNMENT #5 –
Genetic disorders are caused by your DNA. Since your DNA is inherited from your
parents (and your parents inherited this DNA from their parents), any changes to
the DNA sequence can be passed from one generation to the next. In general,
genetic disorders can be classified into two groups: chromosome disorders and
gene disorders. In chromosome disorders, an entire chromosome is missing or an
extra one has been added. As a result, humans with chromosome disorders may only
have 45 chromosomes or could have as many as 47 chromosomes in each of their
cells. In gene disorders, only a small section of a chromosome (a gene) is changed.
However, even a small change can have a huge effect on the person who has a gene
disorder.
1. Define the following terms:
-
Chromosome Disorder:
-
Gene Disorder:
2. In all cases, you were assigned a gene disorder. To be a gene disorder, one or
more genes are affected. What is the name of the gene that is causing this
genetic disorder? NOTE: There may be more than one gene. If so, select two
(your choice) to focus your attention.
NAME OF GENE(S):
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3. Each gene can be found on a chromosome. For the gene(s) you listed in question
#2, what chromosome contains this gene?
WHICH CHROMOSOME:
4. Each chromosome can be divided into “p” and “q” sections which are simply
“halves” of a chromosome that are on one side or the other of a centromere.
Centromer
e
p
q
Scientists have likely gone through a process to try to narrow the location of
this gene to a region of that chromosome – the numbers which follow the “p” or
“q”. For example, a gene found on 11q13.3 which means that this gene is on
chromosome 11, the q section, 13.3 units away from the centromere.
WHERE ON THE CHROMOSOME IS THE GENE LOCATED:
5. Each gene serves as a set of instructions to help a cell make a protein. What is
the name of the protein encoded by this gene?
NAME OF PROTEIN:
6. Each protein has a job in a cell or in the body. What is your protein supposed to
do? You will be asked to explain this to everyone else in class during your
presentation to begin to summarize the protein’s function or job in your own
words.
JOB OF PROTEIN:
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7. In the first packet, you were asked to find the symptoms of this disorder.
Regardless of which genetic disorder you were assigned, the gene involved is
not the “normal set of instructions”. As a result, the protein encoded by that
gene is not doing what it is supposed to be doing. How does this lead to the
traits or symptoms of this disorder?
EXPLAIN HOW PROTEIN NOT WORKING RIGHT LEADS TO
TRAITS/SYMPTOMS OF THIS DISORDER:
8. This is a genetic disorder and scientists may have determined whether the
disorder is dominant, recessive, incomplete dominant, co-dominant, sex-linked,
or a different possibility. Research to find how this genetic disorder is passed
from one generation to the next. (NOTE: You will typically see that the
disorder is sex-linked or autosomal. Remember, sex-linked genes are either on
the X or the Y chromosome. Autosomal genes are on one of the other
chromosomes (1 – 22). You should know the specific chromosome number of this
gene. Once you find an answer, you may want to check one of the chromosome
posters in my room to find this gene).
WHAT TYPE OF GENETICS IS INVOLVED IN INHERITING THIS
DISORDER:
-
(NOTE: If this disorder is dominant, then you MUST revise your answer to
the Hardy Weinberg problem in packet #4.)
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9. You have recently learned about pedigrees. Imagine that you are a doctor or
genetics counselor for a family that has just learned that their child has
inherited your assigned genetic disorder. Draw a pedigree that shows how this
child has inherited this disorder and write a paragraph to explain the family
history (a story with your pedigree). Your pedigree must include the following:
-
three generations
at least two children in the second generation
at least 4 people in the third generation
must be accurate for the genetics of the disorder
must have the correct genotypes for each person
PEDIGREE:
STORY:
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The following websites may aid your search:
DON’T JUST TYPE IN THE WEB ADDRESSES. READ THE
SUMMARIES – THEY MAY CONTAIN HELPFUL DIRECTIONS!
www.genetests.org – at this site, you can click on “Gene Reviews”, type in the name of
the disorder, select “reviews”, and then select “molecular genetics”. If known, the name
of the gene, the name of the protein, and the position on a chromosome (chromosomal
locus” will be given. Click on the name of the protein and it will tell you the protein’s
function. Select “genetic counseling” and you will find the genetics of this disorder
(mode of inheritance such as dominant or recessive). You can also enter the name of
the disorder and select “testing” to find out how tests are done to know if someone has
this disorder.
www.ncbi.nlm.nih.gov/disease/ - AWESOME website. If you know the chromosome
that your gene is on, choose that chromosome and click on the name of the gene. If you
don’t know which chromosome to start with, choose the green “click here” button for the
BOOKSHELF. This will take you to a page that has a listing of genetic disorders. These
are grouped by type of disorder. Search the page by selecting “Find” on the toolbar and
entering the name of your assigned genetic disorder. Great summaries!
www.ygyh.org – not available for all genetic disorders, but does contain AWESOME
information and animations for a select few. If you find your assigned genetic disorder
here, congratulations!
www.geneclinics.org/profiles - find your assigned genetic disorder from an
alphabetical listing of a large number of genetic disorders. Click on the name and be
taken to a description of the disorder. Most often, the link is to the www.genetests.org
site (see above).
ghr.nlm.nih.gov/ghr/ - FANTASTIC SITE! If you are having any trouble with your
research, you should be accessing this site. This is the one above all others that you
should use. Great place to begin.
www.nlm.nih.gov/medlineplus/geneticdisorders.html - links to a variety of sites
about genetic disorders; designed by the National Institutes of Health.
gslc.genetics.utah.edu/units/disorders/whataregd/ - if you are struggling to
understand the difference between chromosome and gene disorders, this website will
help you.
www.ncbi.nlm.nih.gov/SCIENCE96/genelist.cgi - an alphabetical listing of a limited
number of genes and genetic disorders. Interesting to compare what was known less
than 10 years ago with the wealth of information available today.
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