Selective breeding and genetic engineering - armstrong-herrington

stubbornnessuglyBiotechnologie

12 déc. 2012 (il y a 8 années et 7 mois)

350 vue(s)

H
omework: Due Friday, December 9


Selective breeding

is the traditional method for
improving crops and livestock, such as increasing
disease resistance.

Genetic engineering

is a faster way, which
transplants genes for a desired characteristic into
an organism. However, genetic engineering offers
many potential benefits but carries the risk of
unexpected harmful effects.

~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Selective bre
eding and genetic
engineering
:

Over the centuries humans have tried to breed
better crops and livestock. Traditionally this was
done by carefully choosing parents for breeding
that show the required characteristics
-

selective
breeding
. More recently it's
been possible to
implant particular genes using

genetic engineering
.
Both t
hese techniques depend on there
b
eing

change and variation

in the genetic material


which is caused by

mutations
.

Mutation

Mutation means any

change

in the genetic
material.
Mutation occurs

naturally
. Most
mutations are harmful to an individual, but
occasionally a mutation can be beneficial. It's
possible to speed up mutation rates artificially
using radiation or chemicals. Mutations bring about
changes in organisms by changin
g the sequence of
bases in DNA. This causes a different protein to be
made, or blocks the production of the protein
completely.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~






Selective B
reeding

These are the steps in selective breeding:

1.

Decide which

charac
teristics

are important

2.

Choose

parents

that show these characteristics

3.

Select the best

offspring

from parents to breed
the next generation

4.

Repeat the process continuously

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Examples of selective breeding

Wheat

Producing

disease resistant

wheat by crossbreeding
wheat plants with disease resistance and wheat
plants with a high yield

Dairy cattle

Increasing

milk yield

by selecting bulls from high
yield herds and breeding them with cows that have
the best milk produ
ction

Catfish

Producing large, disease resistant catfish that can
survive in low oxygen water and are easy to catch

Selective breeding is a crucial element of any
program to improve commercially important
genetic traits, and tools such as genome maps can
be indispensible to these efforts.


There are also
drawback
s

to selective breeding.
For example,
chickens have been genetically engineered to have
bigger breasts. Because of this phenotype, they
would be unable to survive in the wild. These
chickens wo
uld be unable to fly or get away from
predators easily.







H
omework: Due Friday, December 9





Write a short essay on the
difference
s

between selective
breeding and genetic
engineering.


Your essa
y must include:



examples of both

(wheat, catfish,
peppered moths,
etc.)



the differences
between
selective
breeding and
genetic engineering



advantages of both



disadvantages of
bot
h



facts about both



quotes from
articles on the topic






*
*Use different sources

besides
this document

if you want
,
including the article on
engineered catfish
.


**Your essay must be at least
3

paragraphs


**Essay must have a beginning,
middle and ending.


**Must be in complete sentences
with proper grammar

and
punctuation


**You can use my computers
during homeroom to gather
information


**
DO
NOT
PLAGARIZE



This
means do not write from any
source word for word. I have a
n
online

document checker that can
detect plagiarism.