Transcript What is DNA?

What is DNA?
• Large molecule
contained in
chromosomes, makes up
chromosomes,
responsible for all your
traits
• Deoxyribonucleic acid
• James Watson and
Francis Crick discovered
the double helix, DNA
model (1953)
Structure of DNA
• Double Helix – looks
like a ladder
• Sides made up of
Sugar
• Steps made up of
nitrogen bases, that
have specific pairs
• Bases are Adenine,
Thymine, Cytosine,
Guanine.
Replication
Replication
• Body cells reproduce by a
process of Mitosis.
• Replication is the process
by which DNA duplicate in
order to form two
identical cells
• Cells need to reproduce
to create new cells for
growth, repair of tissue,
(healing) and to produce
other things our body
needs.
• Why do the body cells
have to be identical?
The Role of DNA
• The DNA molecule or
ladder can have
thousands of steps or
base pairs.
• The number and
arrangement form a
genetic “code”
• This determines the
kind of genes, which
determine the inherited
traits of an organism
• Genes are part of
chromosomes and
control inherited traits
What is Protein Synthesis?
• DNA controls an
organism’s traits by
producing certain
proteins.
• Protein synthesis is the
process by which
proteins are made by
the cell.
• DNA has the code or
blue print for building
proteins
• RNA is a single strand
nucleic acid that is used
in the making of
proteins.
• Amino acids are the
building blocks of
proteins.
What makes you, you?
• Play Genetics 101 clip.
What are chromosomes?
• Fine thread like
structures located in a
cell’s nucleus.
• Chromosomes control
heredity
• Chromosomes are made
of chromatin, which are
very long thin strands of
DNA
• Chromatin is wrapped
tightly together around
a protein in an X shape
• Chromatids is one part
of the X shape, held
together by a
centromere.
What are Karyotypes?
• Karyotype organized
display of an organism’s
chromosomes.
• Centromere – point of a
chromosome where two
parts meet.
• Gene is a part of a
chromosome that
controls inherited traits
• Chromosomes come in
pairs, Alleles are
different versions of
the same gene. (usually
one from the mother
and one from the
father)