Results
A detailed analysis
of the student answers is given below. When we look at the answers of
the pre-service teachers concerning the discoverers of the B-DNA
molecule and the discovery year of B-DNA, we see that 17% of the
students gave correct answers about the name of the discoverers, and
83% answered incorrectly or didn’t answer at all. In
addition, 96% of the pre-service science teachers gave wrong answers to
discovery date of DNA (1950, 1937, etc.). The responses given by the
144 pre-service science teachers to the question about the structure of
B-DNA including details like the number of DNA strands, chemical
compositions, types of bonds, specific dimensions and complementary
nature are shown in the Table 1.
Table 1. Analysis
of responses of 144 pre-service teachers regarding the B-DNA structure
|
Structural details
of B-DNA
|
Completely correct
response (%)
|
Incorrect/Partly
correct response (%)
|
Not attempted (%)
|
|
Number of strands
|
46
|
44
|
10
|
|
Chemical composition
|
60
|
35
|
5
|
|
Types of bonds
|
6
|
49
|
45
|
|
Specific dimensions
|
6
|
40
|
54
|
|
Complementary nature
|
49
|
51
|
0
|
While 46% of the
pre-service teachers responded correctly to the number of DNA strands,
44% gave wrong responses or responses without scientific relevance. 10%
of the pre-service teachers didn’t respond to the question.
60% answered correctly to the question regarding the chemical
composition of DNA. 35% gave wrong responses and 5% didn’t
answer. Some of the non-scientific alternative responses given by the
pre-service teachers included amino acids and ribose saccharin. Some
alternative conceptions about types of DNA bonds are Van der
Waal’s bonds and covalent bonds. As for the question about
the specific dimensions of DNA, a few of the pre-service teachers, 6%,
gave correct responses, while the majority (94%) gave wrong answers or
didn’t respond. While 49% of the pre-service teachers
correctly answered the question about the complementary nature of DNA,
51% gave wrong and non-scientific responses (Table 1).
The question which
asked what the gene does as a means of expression, approximately 50% of
the pre-service teachers gave correct answers, while the other half
gave wrong answers or answers without scientifically relevant
responses.
When asked to draw
the schema of the central dogma, it was revealed that 80% of the
pre-service teachers couldn’t draw or didn’t give
any responses. (For example RNA-DNA-Protein).
For the questions
asked to learn about the knowledge of the pre-service teachers
regarding cloning, gene cloning, animal cloning, 42% of the pre-service
teachers mentioned both animal and gene cloning. When the question
regarding gene cloning was specifically asked, 11% of the pre-service
teachers gave scientifically valid, meaningful responses. When asked
specifically about animal cloning, only 6% of the pre-service teachers
were knowledgeable about the subject. Some of the pre-service science
teachers were aware of cloned animals like Dolly.
Some of the
acceptable thoughts of the pre-service teachers about cloning, gene
cloning and animal cloning are as follows:
Acceptable ideas
about cloning:
It is the forming of
a genetic copy of an organism or cell. It is copying the same type of
organism from someone’s cell. It is the copying of genetic
material of an organism. It is copying; copying an organ may be the
cure to most illnesses. It is copying DNA that carry the same genotype
of an individual. Cloning means copying, in other words,forming a
characteristic from the same characteristic. It is forming the same or
similar organism by transferring a DNA to ovule.
Acceptable ideas
about gene cloning:
It is the copying of
the genetic code of an organism that carries all its vital
characteristics. It is the exact copying of a gene with its codes. It
is the transfer of a gene taken from the stem cell of an organism to
another organism. It is the forming the double of a gene with the same
characteristics. It is forming another gene with the same
characteristics of a gene. As a defense against illnesses, it is
transferring the genes of an organism to other organisms.
Acceptable ideas
about animal cloning:
It is the forming a
duplicate of an organism by copying the genetic material of an animal.
It is the copying of an animal.
Some examples of the
alternative conceptions of the pre-service science teachers with no
scientific validity about cloning, gene cloning, animal cloning;
Alternative
conceptions about cloning:
It is obtaining a new
organism 100% similar to previous organism. It is transferring the
characteristic of an organism to another organism. They are copied
cells without any genetic change. It is creating the same DNA batch
with another DNA batch. It is creating more cells from one cell with
the help of fertilization. It is creating a new organism from an
existing organism. It is creating individuals with the same phenotype
and genotype. It is the studies in which the DNA bond is multiplied in
artificial environment for creating organisms.
Alternative
conceptions about gene cloning:
It is creating the
same gene. It is the copying of genes without making any changes in
their genetic structure. It is the process of creating new genes by the
genes through other genes. It is transferring the gene of an organism
to the new organism which will form. It is copying a characteristic of
an organism. It is creating a new individual with the same DNA sequence
but different kind.
Alternative
conceptions about animal cloning:
It is copying all the
animal’s genes. It is creating a new kind of animal type
based on strong characterized egg and sperm cell from the animals. It
is transferring the egg of the helper mother, which was impregnated in
an outside setting to the carrier mother.
As for the question
about DNA fingerprinting, only 22% of the pre-service teachers
responded with meaningful opinions, while 78% didn’t answer
or responded with no scientific validity.
As for the question
which regarding who should be able to access to the genetic profile of
an individual, 51% of the pre-service teachers stated the doctor and
only the person concerned, 28% replied the person and immediate family
members, 10% replied the police and security agencies, 11% responded as
nobody, employer, school and college officials etc (Table 2).
Table 2. Pre-service
teachers’ choices about the preference to access genetic
information.
|
|
%
|
|
Doctor and only the
person concerned
|
51
|
|
Person and
immediate family members
|
28
|
|
Police and security
agencies
|
10
|
|
Other
|
11
|
When the pre-service
science teachers were asked if they ever heard of GMOs, 86% stated that
they had not and that they had no idea how the GMOs were created. From
those who said they had heard of GMOs, they didn’t give any
meaningful responses.
When the pre-service
teachers were asked to write down some of the GMOs and GM drug names,
92% didn’t responded. A few of the pre-service teachers gave
examples of banana, corn and tomato.
To the question that
asked, “should GM plants allowed to be grown in
Turkey”, 38% of the pre-service science teachers responded
positively. Among those who replied negatively, they gave such
responses as “they might create health problems, it is not
ethical, .........’’
Copyright
(C)
2008
HKIEd APFSLT.
Volume
9,
Issue
1,
Article 8 (June, 2008).
All Rights Reserved.
