This presentation is on the topic of DNA. It covers all general and basic criteria of DNA.It would help you to understand DNA from basic level and provide you clear concepts.

1. Group Members
 Hafiza Ramsha Mushtaq
 Daniyal Ahmad
 Usman Abdullah
 Awais Iqbal

2. DNA

3. Context
 What does DNA stands for?
 Who discover DNA?
 What is DNA?
 Chemical Composition of DNA.
 Structure of DNA.
 Where DNA is found?
 What does DNA do?
 Applications of DNA

4. What does DNA stands for?
DNA stands for
deoxyribose
Nucleic Acid
or
deoxyribonucleic
acid.

5.  Who discover DNA?

7.  What is DNA?
• DNA is the hereditary material in humans and
almost all other organisms.
• DNA is a molecule that carries most of the
genetic instructions used in the development,
functioning and reproduction of all known
living organisms and many viruses.
• Every set in human body has a complete set of
DNA.
• DNA is unique for each individual.

8.  Chemical Composition of DNA:
DNA is composed of chemical building blocks called
nucleotides. These building blocks are made of three
parts
• A phosphate group
• A pentose sugar
(deoxyribose)
group
• One of four types
of nitrogen bases.

9.  The four types of nitrogen bases found in
nucleotides are
• Adenine (A)
• Thymine (T)
• Guanine (G)
• Cytosine (C)
Adenine is always matched
with thymine and guanine
with cytosine.

10. 

11.  Structure of DNA:
• Discovered by Watson and Crick.
• Double helix:
1. Spiral staircase.
2. Two strands of nucleotides.
• Side rails-sugar and phosphate.
• Rungs-nitrogen bases
o A----T
o C----G
These dash lines ---- represents Hydrogen bonds

12.  Hydrogen Bonds:
• A double bond is present between adenine
and thymine.
• A triple bond is present between guanine
and cytosine.

13.  Purine and pyramidine:
Nitrogenous bases
are either purines or pyramidines
• Purine:
It includes adenine
and guanine.
• Pyramidine:
It includes cytosine
and thymine.

14.  For Information:
• Base pairs in DNA are 0.34nm apart and
each turn of the double helix has 10 base
pairs.
• Human contains about
3 billion bases and
about 20,000 genes on
23 pairs of
chromosomes.

15.  Where DNA is found?
• Most DNA is located in the cell nucleus
where it is called nuclear DNA.
• But a small amount of DNA can also be
found in the
mitochondria
where it is
called
mitochondrial
DNA or
mtDNA.

16.  What does DNA do?
• DNA contains the instructions needed for
an organism to develop, survive and
reproduce.
• The molecule determines not only what
physical characteristics you will have, such
as hair and eye color, but also what
diseases you may develop.

17.  “Applications of DNA”
There are many applications of DNA. We will
discuss a few of them here, which are.
1.The polymerase Chain Reaction.
2. Diagnosis.
3. Use in forensic laboratories.
4. Parentage.
5. Determination of the evolutionary
history of human population.

18. 1. The polymerase Chain Reaction:
“ The technique in which DNA is copied many time
by the enzyme DNA polymerase in test tube is
called polymerase chain reaction.”
 Steps:
i. DNA polymerase
ii. Primer DNA
iii. High Temperature
iv. PCR machine and
thermocycler.
v. PCR and Gene.

19. 2. Diagnosis:
DNA analysis are used to diagnose viral infections,
genetic disorder and cancer.

20. 3. Use in forensic laboratories.
• DNA analysis is used to identify criminals
• The cell of the criminal which is obtained from
the dead body can be used to identify the
murderer just because of DNA.

21. 4. Parentage
• Child receives DNA from both of the parents.
Some parts or band of DNA of the child
resembles father and some part of the DNA
resembles mother. But however some bands or
section of DNA of the child is unique to him/her.
• A child may recognize his or
her parents with the help of
DNA because of the fact that
his/her DNA resembles to
his/her parents.

23. 5. Determination of the evolutionary history of
human population
The evolutionary history of human population can
be determined by DNA analysis.The DNA of
human brain was taken from a 76,000 years old
mummified man. Similarly DNA from 17 to 20
million years old plant fossil was taken. The
sequence of these DNA was determined by PCR
amplification(Copy).

24. Thank You