EXERCISE 1
July 3, 2013 TYPES OF VARIATION
Differentiate the types of variations
Illustrate the variations noted in the specimen
and,
Appreciate the beauty and wonders of the
things around brought by the types of
variations
OBJECTIVES
variation
basic quality of an organism
phenotype
an individual’s observable trait (height, eye color, and blood
type)
genotype
genetic contribution of the phenotype; a collection of genes; a
combination of alleles for a particular gene
GENOTYPIC VARIANCE
variation in phenotype caused by genetic make-up additive variance (deviation from mean phenotype due to
inheritance of a particular allele; average differences)
dominance variance (expression is not equal)
epistatic variance (interaction with alleles but associated with different loci)
ENVIRONMENTAL VARIANCE specific environmental variance (deviation from mean due to envt
conditions uniquely experienced by individual)
general environmental variance (non-genetic sources experienced by multiple individuals in population)
genotype by environment interaction (unique or diff responses of genetic lines to GEV)
MAJOR CAUSES OF VARIATION
In a CORN, genes A and B control the yield of the corn.
A – 2 corns a – 1 corn
B – 6 corns b – 3 corns
each allele will contribute to the yield of the corn
AaBb X AaBb AABB - 16 (2+2+6+6) AABb - 13 AABb - 13
AaBB - 15 Aabb - 9 AaBb - 12
aaBB - 14 aabb - 8 aaBb - 11
ADDITIVE VARIANCE
A plant produces white flowers if its genotypes are A1A1 and
red flowers if its genotypes are A2A2
we would assume that A1A2 leads to pink flower but in
dominance variance there is NO MIDPOINT
If A2 is dominant, A1A2 would produce red flowers
DOMINANCE VARIANCE
In the same flower, a B1 gene produces pigment whereas a B2
gene does not produce any pigment (flower appears white)
A2A2B1B1 – red flower
A1A1B2B2 – white flower
A2A2B2B2 – white flower
EPISTATIC VARIANCE
5 pcs common fruit belonging to same species
5 pcs mayana, San Francisco, or Duranta leaves
5 pcs flowers of any plant species
2 groups of 5 invertebrates
Drawing materials and coloring pens
ruler
MATERIALS
A. Variation in plants
Examine the 5 fruits, the 5 leaves and the 5 flowers
of the plant specimens that you brought. Note the
variations in size, shape, color, and their other
features.
Illustrate and list down at least 5 variations that you
have observed in each of the specimens.
Compute for the total magnification of each
specimen.
PROCEDURE
B. Variations in animals
Do the same in your animal specimens. Observe not only its
morphological or anatomical variations but also their
similarities and differences physiologically, behaviorally and
sexually.
Compute for the total magnification of the specimen.
All drawings must be of 50 mm. in length and in width.
Computations about reduction and magnification must be
included. Determine if the specimen is magnified or reduced.
PROCEDURE
Name Date
Course/Yr/Section
Types of Variation
A. In Plants
1. Fruits of
(illustrations)
Similarities Differences
1. 1.
2. 2.
3. 3.
4. 4.
5. 5.
Computations of magnification:
FORMAT
Types of Variation
2. Leaves of
(illustrations)
Similarities Differences
1. 1.
2. 2.
3. 3.
4. 4.
5. 5.
Computations of magnification:
FORMAT
Types of Variation
3. Leaves of
(illustrations)
Similarities Differences
1. 1.
2. 2.
3. 3.
4. 4.
5. 5.
Computations of magnification:
FORMAT
Types of Variation
B. In animals
1. (Common name: _________)
(illustrations)
Similarities Differences
1. 1.
2. 2.
3. 3.
4. 4.
5. 5.
Computations of magnification:
FORMAT
Types of Variation
B. In animals
2. (Common name: _________)
(illustrations)
Similarities Differences
1. 1.
2. 2.
3. 3.
4. 4.
5. 5.
Computations of magnification:
FORMAT
1. What is variation. Give its importance.
2. What are the possible causes of variations? Give specific examples.
3. How would you know or identify if the cause of variation is genetic, environmental, or both?
4. Classify these variations as to “species characteristics” or “individual characteristics”.
Thorns in the stalk of the rose flower
Body size of ants
Color of apple skin
Color mosaic in San Francisco leaf
Number of body segments in worm
QUESTIONS
Make a survey of at least ten 2 nd or 3 rd year college students.
Note their sex, age, height, weight, and thumbprint.
Fill out Table 1
With the guide, classify the dif ferent surveyed thumbprints.
Summarize the data gathered on age, height and weight and
complete Table 2
Make a list of twenty (20) human traits and classify them as
to morphological, physiological, sexual or behavioral
variations. Fill out Table 3.
CONT. HUMAN VARIATIONS
FINGER PRINT CLASSIFICATION
Start collecting wild-type fruit flies
Place banana or its peel in a jar and expose near a garbage
can.
Observe frequently until enough fruit flies are trapped in the
jar. Cover with paper and poke the paper with pin (enough to
produce air circulation) Secure the paper with rubber band. Do
not keep in locker or expose in direct sunlight. Keep in room
temperature.
Keep collecting for culturing.
REMINDERS
Bring:
Samples of the fruit fly.
Hand lens
cotton balls
scissor
scotch tape
face mask
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