Download dominant gene

Interest Approach

Approach 1:

Discuss the demand on farmers to produce
enough food for the billions of people on
Earth. Also discuss how the land available
to farmers continues to decrease because
of new buildings like subdivisions, malls,
and the expansion of cities. Use an apple
to demonstrate the small amount of land
we have available for food production:
Interest Approach Continued

Approach 2:

Have students taste test apple, cereal, and tofu.
After they have eaten, explain to them that these
food products and many others are involved in
biotechnology.
Student Learning Objectives. Instruction in this
lesson should result in students achieving the
following objectives:
1 Describe how biotechnology directly affects
the lives of humans.
 2 Explain how DNA influences the ways that
people, animals, and plants grow.
 3 Explain how biotechnology is applied in
agriculture.

Terms. The following terms are presented in this
lesson (shown in bold italics):









Biotechnology
Bovine somatotropin (bST)
Bt corn
DNA
Dominant gene
Double helix
Gene
Genetic code
Recessive gene
OBJECTIVE 1: Describe how biotechnology
directly affects the lives of humans.

Anticipated Problem: How does
biotechnology directly affect our lives?

I. Biotechnology: ‘Bio’ meaning biology
or living things and ‘technology’ meaning
tools. Biotechnology is a science that
uses living things to make new products.
OBJECTIVE 1 continued

A. All living things have a
blueprint that determines what
that organism will look, act,
and feel like, or the living
thing’s traits.
1. This blueprint is a specific
genetic code.
 2. This genetic code
determines what color a
flower will be, what an apple
will taste like, or what color a
child’s eyes are.

OBJECTIVE 1 continued

B. Biotechnology can be used to help humans.

1. Biotechnology improves foods and crops by
adding specific characteristics that give the
plant new benefits. For example, biotech rice
contains more iron than regular rice.
2. A specific gene is taken from one plant and
placed into the DNA of a second plant. The
second plant will then grow with all its own
traits plus the one from the first plant.

OBJECTIVE 2: Explain how DNA influences the
way people, animals, and plants grow.

Anticipated Problem: How does DNA
influence the way organisms grow?

II. Since the discovery of DNA, scientists
have studied how DNA relates to the
growth of organisms.
OBJECTIVE 2 continued

A. Basic background of genes.
1. A gene determines what an organism’s
offspring will look and feel like.
 2. All living things have genes. Each
organism has between 50,000 and
100,000 genes.
 3. Genes are a part of a DNA molecule in
a chromosome, which is found in a cell.

OBJECTIVE 2 continued


4. Human beings have two of every type of gene.
One gene is received from the mother and the other
from the father.
5. Genes can be dominant or recessive. Two
dominant genes will allow the dominant
characteristic to appear. Two recessive genes will
cause the recessive trait to be displayed. If one
dominant and one recessive gene are paired, the
dominant gene will overpower the recessive gene
and the characteristic of the dominant gene will
appear in the offspring.
TT
two dominant genes
tt
two recessive genes
Tt
one dominant gene and one recessive gene
OBJECTIVE 2 continued

6. The probability of a genetic outcome
can be determined using a Punnet Square.
Plant 2: Tt
T
t
T
TT
Tt
t
Tt
tt
Plant 1: Tt
OBJECTIVE 2 continued

B. DNA is made up of
genes.

1. DNA
(deoxyribonucleic acid)
is the molecule in a
chromosome that
furnishes the genes with
information for their
development.
OBJECTIVE 2 continued

2. There are four
different bases on a
DNA molecule:
 a. Adenine (A)
 b. Thymine (T)
 c. Guanine (G)
 d. Cytosine (C)
h
T
d
A
h
d
p
h
p
C
G
h
d
h
d
p
p
h
T
A
h
d
d
p
h
p
G
C
h
d
h
d
p
h
p
T
d
h
A
d
OBJECTIVE 2 continued

3. These four bases form base pairs.
 a. Adenine joins with Thymine (A–T)
 b. Guanine joins with Cytosine (G–C)

4. A DNA strand is twisted in a double helix.
A double helix is the spiral structure that
DNA forms. The average length of a DNA
strand is 6 feet long!
OBJECTIVE 3: Explain how biotechnology is
applied in agriculture.

Anticipated Problem: How does
biotechnology work in agriculture?

III. Biotechnology lets researchers take
good traits from one organism and place
them into another, creating a better
organism. Biotechnology can be used to
improve many agriculture products.
OBJECTIVE 3 continued

A. Milk

1. Through biotechnology, researchers have
been able to increase the amount of milk a dairy
cow can produce by increasing the amount of
the bovine growth hormone, known as bovine
somatotropin (bST), which is the hormone
secreted by the pituitary gland that regulates
milk secretion by the mammary glands of cows.
2. bST is a protein that increases the amount of
energy cows put toward producing milk. In other
words, bST redirects the energy cows get from
feed from weight gain to milk production.

OBJECTIVE 3 continued
3. Cows naturally produce bST in their
bodies but not in large amounts.
Biotechnology has allowed researchers to
put the gene that controls bST production
into the DNA of a harmless bacteria.
 4. This bacteria is then injected into the
cow’s system, resulting in increased bST
production and increased milk production.

OBJECTIVE 3 continued
5. Through the use of this
biotechnology, milk production
can be increased by 10 to 25 percent.
 6. The milk causes no harmful side
effects in humans because bST is a
natural hormone that has always been
present in milk.
 7. There are also no side effects for the
cows.

OBJECTIVE 3 continued

B. Insecticides
1. Farmers use insecticides to fight
damage to crops caused by insects.
Insecticides are traditionally sprayed
on the field to kill the harmful bugs.
 2. Spraying can sometimes cause
environmental problems, such as
drifting and runoff into nearby streams.

OBJECTIVE 3 continued

3. Biotechnology
researchers have taken
genes from plants that
naturally kill the insects
that harm corn and placed
these genes into the DNA
of the corn. The result is Bt
corn, a corn plant that can
kill harmful bugs on its own
without the use of spray
insecticides. This
technology has also been
used in potatoes, cotton,
and rice.
OBJECTIVE 3 continued

C. Golden rice
1. Golden rice was a huge breakthrough for
the biotechnology industry. This rice
contains increased amounts of betacarotene and iron.
 2. The beta-carotene is made into Vitamin
A by the human body and prevents
infection and blindness. More than 400
million people worldwide suffer from a
Vitamin A deficiency.

OBJECTIVE 3 continued
3. Iron is needed to maintain the human
body. People with an iron deficiency suffer
from anemia. There are 3.7 billion people
worldwide who do not get enough iron.
 4. The creation of golden rice was
especially important to people in
developing countries who depend on rice
as a dietary staple but who were not
receiving enough nutrients. The
introduction of this rice allowed them to
grow rice that was full of needed nutrients.
 5. The genes to create this rice came from
a number of different sources, one of those
being daffodils.
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REVIEW

1. How does biotechnology directly
affect our lives?

2. How does DNA influence the way
organisms grow?

3. How does biotechnology work in
agriculture?