Genetic material is either DNA or RNA. DNA contains genes that code for proteins and is a double-stranded molecule, while RNA is single-stranded. Nucleotides are the building blocks of nucleic acids and contain a sugar, phosphate, and nitrogenous base. DNA nucleotides contain the bases adenine, thymine, cytosine and guanine, while RNA contains adenine, cytosine, guanine and uracil instead of thymine. The bases on one strand pair with those on the other through hydrogen bonding in a specific way - adenine pairs with thymine/uracil and cytosine pairs with guanine. DNA replicates accurately to ensure progeny cells have the same genetic makeup.

1. 



Genetic material of living organisms is either
DNA or RNA.
DNA – Deoxyribonucleic acid
RNA – Ribonucleic acid
Genes are lengths of DNA that code for
particular proteins.
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2. 

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Both DNA and RNA are polynucleotides.
They are made up of smaller molecules called
nucleotides.
DNA is made of two polynucleotide strands:
Nucleotide
Nucleotide
Nucleotide
Nucleotide
Nucleotide
Nucleotide
Nucleotide
Nucleotide
Nucleotide
Nucleotide

RNA is made of a single polynucleotide strand:
Nucleotide
Nucleotide
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Nucleotide
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Nucleotide
Nucleotide
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3. A nucleotide is made of 3
components:
 A Pentose sugar
 This is a 5 carbon
sugar
 The sugar in DNA is
deoxyribose.
 The sugar in RNA is
ribose.
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4. 

A Phosphate group
Phosphate groups are
important because
they link the sugar on
one nucleotide onto
the phosphate of the
next nucleotide to
make a
polynucleotide.
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5. 
A Nitogenous base

In DNA the four bases are:





Thymine
Adenine
Cytosine
Guanine
In RNA the four bases are:




Uracil
Adenine
Cytosine
Guanine
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6. Pyramidines
Purines
Thymine - T
Cytosine - C
Uracil - U
Adenine - A
Guanine - G
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10. 

Nucleotides are
connected to each other
via the phosphate on
one nucleotide and the
sugar on the next
nucleotide
A Polynucleotide
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12. 
The Nitrogenous
Bases pair up with
other bases. For
example the bases of
one strand of DNA
base pair with the
bases on the opposite
strand of the DNA.
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16. 
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Adenine always base pairs with Thymine (or
Uracil if RNA)
Cytosine always base pairs with Guanine.
This is beacuse there is exactly enough room
for one purine and one pyramide base between
the two polynucleotide strands of DNA.
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17. Purines
Pyramidines
Adenine
Adenine
Thymine
Uracil
Guanine
Cytosine
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18. 

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Property 1 - it must contain, in a stable form,
information encoding the organism’s
structure, function, development and
reproduction
Property 2 - it must replicate accurately so
progeny cells have the same genetic makeup
Property 3 - it must be capable of some
variation (mutation) to permit evolution
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19. 

Speed of DNA replication:
3,000 nucleotides/min in human
30,000 nucleotides/min in E.coli
Accuracy of DNA replication:
Very precise (1 error/1,000,000,000 nt)
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23. 3H-labelled
after one further replication
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chromosomes
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27. Origins initiate
replication at
different
times.
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