Download Genetic Engineering Topic #0008D By: Tony Hoffman

Genetic Engineering
0008D
Tony Hoffman
What is Genetics…?
What do things look like? and why?
Genetics
The study of genes and heredity, or how characteristics
are passed from parents to children.
All Definitions from: http://library.thinkquest.org/19037/glossary.html
Why do things look
the way they do?
•DNA (deoxyribonucleic acid) - a large double-stranded, spiraling
molecule that contains genetic instructions for growth,
development and replication.
•This DNA is a set of instructions that tells cells to form in a
particular way. DNA is the reason we have so many
different kinds of cells. It is very small and large amounts
can be found in each cell.
http://teachers.teach-nology.com/web_tools/web_quest/
What is DNA made up of?
Bases - the molecular building blocks of DNA: adenine (A),
cytosine (C), guanine (G) and thymine (T). In DNA, A attaches
only to T, and C attaches only to G. These pairs are called base
pairs.
http://nurseweb.ucsf.edu/www/cardio.htm
Is DNA a long strand that travels
throughout an organism? No.
•Chromosome - a long coiled strand
in the nucleus, made up of
DNA and protein.
•DNA is organized into segments so
that it is not one long strand. These
segments are called chromosomes.
http://www.efa.org/research/gdp/genome.html
Chromosomes are broken down
further into……
•Gene - the unit of heredity in
chromosomes; a segment of doublestranded DNA.
•Genes are small little individual segments
on each chromosome (the colors on the
picture). Each of these genes is a different
trait that is displayed by the organism that
carries it. A chromosome can carry
thousands of genes.
http://www.efa.org/research/gdp/genome.html
Can we change DNA?
Yes we can…by a method called Gene Splicing - the process of
cutting the DNA of a gene in order to add base pairs.
1. Chemicals called restriction enzymes act as the scissors to
cut the DNA. Once it finds that sequence in a strand of
DNA, it attacks it and splits the base pairs apart, leaving
single strands at the end of two double strands.
2. Scientists are then free to add any genetic sequences they
wish into the broken chain.
3. Afterwards, the chain is repaired (as a longer chain with the
added DNA) with another enzyme called ligase.
http://library.thinkquest.org/19037/therapy2.html