WORKSHEET 10
Group No.: 3
Members: Elmer John Castro
Jay Arthur Guanzon
Charry Shane Peluta
Date Performed: _______________
Date Submitted: _______________
Objectives:
1. Identifying the differences between Identical and Fraternal twins
2. Examining the role of genetic and environmental influences on a specific trait
DATA SHEET
Name of Twins:
Jane Anne
Jane Keith
Age: 15
Type of Twin (fraternal/identical): Identical
Table. 10.1. Table showing the anatomical, physiological and behavioural traits of the studied
twins.
Trait
Jane Anne
Jane Keith
A. Anatomical trait
1. Height
5’0
5’0
2. Weight
45 kg
46 kg
3. Skin color
Fair
Fair
4. Pimple
None
None
5. Sex
Female
Female
B. Physiological trait
1. Blood type
A
A
2. Blood pressure
Normal
Normal
3. Allergy
None
None
C. Behavioral trait
1. Handedness
Right
Right
2. Temper
Stable
Stable
3. Sociability
Extrovert
Introvert
Name of Twins:
Honey Grace
Hanna Grace
Age: 19
Type of Twin (fraternal/identical): Fraternal
Trait
Honey Grace
A. Anatomical trait
1. Height
5’0
2. Weight
48 kg
3. Skin color
Fair
4. Pimple
None
5. Sex
Female
B. Physiological trait
1. Blood type
B
2. Blood pressure
Normal
3. Allergy
None
C. Behavioral trait
1. Handedness
Right
2. Temper
Stable
3. Sociability
Introvert
Hanna Grace
5’2
50 kg
Fair
None
Female
B
Normal
None
Right
Stable
Extrovert
TWIN STUDY CLASS DATA
TRAIT
Height
Weight
Skin color
Pimple
Sex
Blood type
BP
Allergy
Handedness
Temper
Sociability
Trait
Height
Weight
Skin color
Pimple
Sex
Blood type
BP
Allergy
Handedness
Temper
Sociability
+ concordant
- disconcordant
IDENTICAL TWINS
TOTAL
FRATERNAL TWINS
1
2
3
4
+
1
2
3
4
+
+
+
3
1
0
4
+
+
+
+
4
0
+
+
+
+
+
2
2
+
+
+
+
+
+
+
4
0
+
+
+
+
+
+
+
+
4
0
+
+
+
+
+
+
+
3
1
+
+
+
+
+
+
3
1
+
+
+
+
+
3
1
+
+
+
+
2
2
+
+
+
1
3
-
IDENTICAL (n=4)
FRATERNAL (n=4)
TOTAL
+
0
4
0
4
3
1
3
1
4
0
4
0
3
1
2
2
2
2
2
2
0
4
Legends:
Positive:
Negative:
Assessment Questions:
1. Differentiate identical and fraternal twins.
Identical twins- are also called monozygotic twins. They result from the fertilization of a
single egg with a single sperm. And at some point, very early in embryonic growth they
split into two individuals.
Fraternal twins- are also called dizygotic twins. And the difference between fraternal
and identical twins is that fraternal twins derive from two different eggs. Fraternal twins
may be the same gender, they may have many of the same characteristics, but also may
be very different from each other.
2. Based on the graph, which traits examined would more likely be due to genetic
endowment? Which are more likely be due to the environment? Justify.
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3. What are the applications of twin study?
Twins provide a valuable source of information for health and psychological
research, as their unique relationship allows the researchers to pull apart and examine
the genetic and environmental influences. Twin studies estimates and examine the
overall role of genes in the development of a trait or disorder. The comparisons
between monozygotic twins and dizygotic twins are conducted to evaluate the degree
or extent of genetic and environmental influence on a specific trait. Monozygotic twins
are the same sex and share 100% of their genes. Dizygotic twins can be the same or
opposite sex and share, on average, 50% of their genes.
4. What are the limitations of the study? In other words, what extra care should be
considered when making generalizations based on twin study data?
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