Drosophila Melanogaster Experimentation.pdf

Biology

1. {
EXERCISE 13: Genetics
ROMAN, Joaquin
SAITO, Sarina
SAMONTE, Tiara
SANTOS, Mark

2. Genetics - the study of heredity.
Heredity - a biological process
where a parent passes certain genes
onto their children or offspring.
Variation – difference between
cells, organisms or groups of
organisms. Phenotypic and
genotypic.
GENETICS

3. {
ROMAN, Joaquin
SAITO, Sarina
SAMONTE, Tiara
SANTOS, Mark
EXERCISE 13.1: LIFE
CYCLE OF THE
Drosophila
melanogaster

4. The Drosophila melanogaster or also
known as fruit flies only have 4
pairs of chromosomes compared to
the 23 that humans have. Since they
are easy to understand, they have
been used to study how genes are
passed from generation to
generation.

INTRODUCTION

5. Learn the life cycle of the
Drosophila

Culture the Drosophila

Differentiate the male
Drosophila from the female
Drosophila

OBJECTIVE

6. Drosophila
flies

Culture
bottles

Absorbent
paper strips

Saba bananas

Cotton plugs

MATERIALS

7. 1. Create the bait bottle
by putting fruit peels in a
bottle and putting it in an
open space for at least
three hours.
2. Prepare the culture
bottle by sterilizing it
then mashing two saba
bananas before pouring it
into the bottle until it
reaches up to an inch. Put
an absorbent paper inside
to lessen build-up of the
moisture of the saba
bananas and the flies can
use it for pupation.
3. Create the cotton plug
to be used as the cover for
the culture bottle.
3. When there are at least
ten flies in the bait bottle,
transfer the flies into the
culture bottle.
4. Keep the culture bottle
in a pan with water to
avoid ants and maintain
low temperature.
5. Observe every day and
record the appearance of
stage of the life cycle.
METHOD

8. DAY STAGE OF LIFE CYCLE
1 Eggs
2 Larva
3 Larva
4 Pupation
5 Pupation
6 Pupation
7 New adults emerge from the
cocoons
TABLE 12.1: LIFE CYCLE

13. Pupation takes the longest in the life
cycle of the Drosophila while egg
hatching takes the shortest. It is
because in pupation, the Drosophila
is undergoing a lot of changes for it
to become an adult fruit fly.
CONCLUSION

14. OBSERVABLE FEATURE MALE FEMALE
BODY SIZE Significantly smaller than
the female
Larger than the male (about
25%)
TIP OF THE ABDOMEN Rounded Pointed
NO. OF ABDOMINAL
SEGMENTS
Five (5) segments Seven (7) segments
COLOR OF ABDOMEN There is a bigger black band
on the bottom
Black bands
DISTRIBUTION OF
BRISTLES IN ABDOMEN
Ten stout black bristles Not present
SEX COMB Present Not present
OTHER Penis Vaginal plate
TABLE 12.2: DIFFERENCE BETWEEN MALE
AND FEMALE

19. There are ways to distinguish a
male Drosophila melanogaster from
a female. However, there are ways
that are more accurate than the
others as they are innate only to
the certain sex of the fruit fly. The
best way to identify a male fruit
fly from a female fruit fly is to look
at their genitals.
CONCLUSION