- [Narrator] Genetics helps us understand
the biological programming
behind all life forms.
But what exactly is the
science of genetics?
And what does its future hold?
Genetics is the study of heredity.
The expression of traits
and how they are passed
from generation to generation.
For thousands of years,
humans have observed this
inheritance of traits
and implemented their knowledge
to breed and domesticate
plants and animals.
However, the science behind inheritance
was only starting to be understood
in the mid 19th century.
Around 1865, Austrian monk
and botanist, Gregor Mendel,
published the results of
his hybridization studies
of pea plants.
In his findings, he
noted the role of factors
that influence the expression of traits.
These factors later became known as genes.
Each human has between
20,000 and 25,000 genes.
This collection called a genome,
determines a person's traits
by influencing factors
on a cellular level.
Genetic information is stored
in every cell's nucleus.
Structures called chromosomes
carry this information in the
form of deoxyribonucleic acid
or DNA.
DNA is a double helix of nucleotides,
chemical compounds composed of sugar
and phosphate molecules
along with the bases
thymine, adenine, guanine,
and cytosine.
These segments of DNA
are what we call genes
and it is within those genes
that chemical compounds provide the coding
for all information about a
person's inherited traits.
Human cells contain so much DNA
to carry this large amount of information
that if unraveled, the DNA in each cell
would be over six feet long.
At the turn of the 21st century,
an international effort to
decode human DNA was launched
called the human genome project,
it ended up identifying about 99%
of the entire human genetic sequence.
Discoveries in genetics research
have unearthed tremendous
opportunities in medicine
such as genetic testing and
the manipulation of genes.
But with these opportunities
come risks and ethical questions
and finding the answers to those questions
may be the next stage of our
understanding of genetics.
