DNA and it's role in inheritance

1. ● Presented by: Sawera Rasheed (24)
Sehrish (25)
● Topic: DNA and it's role in inheritance

2. DNA
● The macromolecule that stores all of an organism’s genetic
information.
● DNA is a type of nucleic acid.
● Important property of DNA is that it can replicate or make
copies of itself.
● Chromosome is a long, coiled piece of DNA.
● Gene is segment of DNA that codes for speci c trait or
protein.

3. ● DNA is important for not only humans but also for
other organisms.
● Every cell in person's body has same DNA.
● Structure of DNA was established by Watson and Crick
in 1953.
● Complete set of DNA is called genome. It contain 3
billion bases, 20,000 genes, 23 pairs of chromosomes.
● Inheritance is transmission of information from one
generation to another.

5. Types of DNA
Nuclear DNA
● Most DNA is located in
cell nucleus, called
nuclear DNA.
● It is combination of
both your ancestor's
DNA.
Mitochondrial DNA
● Small amount of DNA
can also be found in
mitochondria, called
mitochondrial DNA.
● Which you can only get
from your mother.

7. How genes are inherited?
● One copy is inherited from mother (via eggs) and other
from father (via sperm).
● Sperm and egg each contain one set of 23 chromosomes
● When sperm fertilizes egg 2 copies of each chromosome are
present ( and therefore 2 copies of gene ) and so an embryo
forms.

9. What role does DNA play in inheritance?
● It packs in all the genetic information and passes it onto the
next generation.
● DNA make gene, gene make chromosomes.

10. DNA and it's role in inheritance
● DNA contain tons of information and is actually very long. If
you took all the DNA out of one of your cell and stretched it out,
it would be about 5 feet long. This is why DNA condenses into
chromosome to t inside the cell.
● The information in DNA is stored as a code made up of four
chemical bases.
1. Adenine (A). 2. Cytosine (C)
3. Thyamine(T). 4. Guanine(G)

12. ● These four bases control everything about an organism
from hair color to number of legs.
● Human DNA consist of 3 billion bases connected together.
● More than 99% of these bases are same in all people.
● They are all sorted in just 23 pairs of chromosomes.
● The order or sequence of these bases determine the
information available for building and maintaining an
organism.
● DNA bases pair up with eachother, A with T, C with G to
form units called base pairs.

13. ● Each base is attached to sugar molecule and a phosphate
molecule.
● Together a base, sugar and a phosphate is called
nucleotide.
● Nucleotides are arranged in 2 long strands that form a
spiral called double helix.
● Order of nucleotide in an organism's DNA results in
physical and even some behavioural characteristics of an
organism.

14. Questions regarding topic
Q1 : De ne the terms, DNA, gene, chromosome, inheritance,
nucleotide, double helix, base pairs, genome.
Q2 : How genes are inherited?
Q3 : What role does DNA play in inheritance?
Q4 : What is the role of nucleotide and four chemical bases?
Q5 : Why do you resemble one parent so much but not other?