Download The Great Divide

Where can you find the
secret code that tells the
body how to build you?
Any idea what these 23 pairs are?
C
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o
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!
Cells contain a genetic code
that is on chromosomes.
The DNA Code
Chromosomes are made of deoxyribonucleic
acid or DNA. Each chromosome contains
thousands of genes. The sequence of bases
in a gene forms a code that tells the cell
what protein to produce.
Change 14
Structure of DNA
The DNA molecule is
shaped like a twisted
ladder.
Change 14
DNA is made up of four nitrogen bases.
Nitrogen bases are molecules that
contain the element nitrogen and other
elements
DNA has four kinds of nitrogen bases:
(A) adenine, thymine (T), cytosine (C), and
guanine (G).
Each of the bases pairs together like
rungs of a ladder.
(A) adenine pairs with thymine (T) and
cytosine (C) pairs with guanine (G).
Change 14
How Cells Make
Proteins
During protein synthesis, the cell uses
information from a gene on a
chromosome to produce a specific
protein.
Change 14
How Cells Make
Proteins
A group of three DNA bases
codes for one specific
protein.
The order of the three-base
code determines the order in
which amino acids are put
together to form a specific
protein.
Change 14
BrainPOP! DNA
Matching
DNA
gene
chromosome
base
condensed DNA
DNA between a start and
stop point = one protein
four of these make up
the DNA code; form pairs
deoxyribonucleic acid
(nucleotide)
Protein Synthesis
DNA provides code to form messenger RNA.
Messenger RNA attaches to ribosome.
Transfer RNA “reads” the messenger RNA.
Amino acids are added to the growing
protein by transfer RNA.
Change 14
• Reading:
• Activity: Mitosis
Tracing
1. What is the full name of the chemical substance represented
by the letters DNA?
2. The smallest molecules that make up DNA are called _____.
3. Name the two pairs of nitrogen bases that make up the
‘rungs’ of DNA.
4. What gives each person a unique DNA code?
5. Describe two characteristics of a gene.
6. When DNA condenses before cell division what does it form?
7. Write the following three terms in the correct order for cell
division by mitosis: cytokinesis, interphase (DNA duplication),
and mitosis.
8. Which is the correct order for the steps of mitosis?
9.
Mitosis has only _____ division step, while meiosis has
_____ divisions.
10. The result of mitosis is _____ cells each with genetic
material _____ to the parent cell. Meiosis results in
_____ gametes, each with only _____ the genetic material
of the original cell.
1. What is the full name of the chemical
substance represented by the letters
DNA?
2. The smallest molecules that make up
DNA are called _____.
3. Name the two pairs of nitrogen bases
that make up the ‘rungs’ of DNA.
Change 14
4. What gives each person a unique DNA
code?
5. Describe two characteristics of a
gene.
6. When DNA condenses before cell
division it forms:
a. chromosomes
c. nuclei
b. chromatin
d. nucleotides
7. Write the following three terms in the
correct order for cell division by mitosis:
cytokinesis, interphase (DNA duplication),
and mitosis
.
8. Which is the correct order for the steps
of mitosis?
a. prophase, anaphase, metaphase, telophase
b. metaphase, anaphase, prophase, telophase
c. anaphase, metaphase, telophase, prophase
d. prophase, metaphase, anaphase, telophase
9. Mitosis has only _____ division step,
while meiosis has _____ divisions.
10. The result of mitosis is _____ cells
each with genetic material _____ to
the parent cell. Meiosis results in
_____ gametes, each with only _____
the genetic material of the original
cell.
Down’s syndrome, cancer, and obesity
have all been linked to a disorder
where the chromosome has a defect.
Conduct research to discover other
disorders that have been linked to
genes and chromosomes. Report your
findings to your class.
Explore various links about
mitosis, meiosis, genes and
chromosomes.
web links
1. deoxyribonucleic acid
2. nucleotides
3. adenine and thymine, guanine
and cytosine
4. the sequence of nucleotides
[in the DNA]
5. Accept any two reasonable
answers. The following are listed in
the Student Book: basic unit of
inheritance, segment of DNA code, all
genes not the same length, markers
indicate where the gene starts and
stops, and one gene creates only one
protein.
6. a. chromosomes
7. interphase (DNA replication),
mitosis, cytokinesis
8. d. prophase, metaphase,
anaphase, telophase
9. one, two
10. two, identical, four, half