Bio3400
Chapter 1
An Introduction to Genetics
In most organisms, the hereditary
material
is Deoxyribonucleic Acid (
). In eukaryotes, DNA is found mainly in the
nucleus
in
chromosomes
bound with
.
Somatic cells divide by
, where each daughter cell receives a
set of chromosomes, one set from each parent.
Gametes (sperm and eggs) are produced by
and contain a
(single) set of chromosomes.
According to the
theory of inheritance, traits are inherited by
residing on chromosomes and transmitted through
.
A gene and may have several versions, called
, that are caused by changes in the DNA called
. The kind of alleles an individual possesses is called its
.
DNA has a
helix
structure,
comprising two
strands each made up of subunits called
.
According to the central
of
genetics,
is transcribed to
, which is translated into
.
The genetic code consists of
nucleotides present in
. Each triplet encodes for insertion of a specific
acid into a growing
chain.
The process of producing a
via the central dogma is called gene
; the action of proteins play an important role in determining the
of an
individual.
The use of
organisms
has allowed us to understand the genetic basis of inheritance and diseases in humans.
Advances in DNA technology has enabled the science of
to study the entire
of a
species.
A basic technique in molecular DNA manipulation is using
enzymes to produce
DNA and
cloning
of desired genes.
Applications of biotechnology include:
modified crop
plants.
therapy and genetic
testing
for the treatment of genetic
disorders.
animals
and
cloned
animals.
Other applications of genetics include elucidating the evolutionary
relationships
between species and solving
crimes.