APPROVAL SHEET

The complete report of experiment genetic and Evolution with title “Giant

Chromosome” created by:

Name : Andi Nurlaeli

Reg.No : 071404159

Group : IV (Fourth)

Have been checked and consulted by Assistant and Assistant Coordinator and this

report is accepted.

Makassar, November 2009

Assistant Coordinator, Assistant,

Nur Muhajirah Yunus Djumarirmanto,S.Pd Reg.No: 061404049

Known by:

Lecturer of responsibility

Hartati, S.Si, M.siID: 1974 04 05 2000 003 2002

CHAPTER IINTRODUCTION

A. Background

Human as the organism, has as specialize from the other organism. The

specialized include mind and idea. Science that study about organism and the

relationship between one organism and the other organism called biology science.

Biology is central science. This now biology can be relation from all natural

science, and can meet of natural science, humaniora and social science. Biology is

science that invited a person to can doing inspiration. Biology not only about

human, but study about plant and animal.

Genetic is science that study about heredity. Genetic have large veil, have

academic and practice characteristic, likes discuss about the function of

chromosome, heredity and anthropology characteristic, happen of body and

mental deformed that caused by chromosome apartness, appear of diseases

because innate metabolism wrong, several of response variety toward medicines,

transplantation, autoimmune diseases and blood groups.

In the diploid number, chromosomes are always found in pairs. In each

pair there are two identical chromosomes, called homologous chromosomes.

These chromosomes are identical in size, appearance and position of the

centromeres. Apart from this, the two homologous chromosomes are genetically

identical, carrying the same number of genes, controlling the same characters.

One member of each pair is called paternal chromosome since it comes from the

male parent and the other member is called maternal chromosome since it comes

from the female parent. So that the numbers of chromosome in the body cells

called diploid (2n). Sex cells (gamete) just contain a half from the chromosome

number that found in the somatic cells, because the number of chromosome in the

gamete called haploid (n). One pack of haploid chromosome in the species called

genome. Chromosome divided between autosom (body chromosome) and sex

chromosome. Fruitfly (Drosophila melanogaster) that usually used to observation

of genetic have 8 chromosomes that consist of 6 autosom and 2 sex

chromosomes. Because of that easily of our doing observation about the giant

chromosome at Drosophila melanogaster.

B. Purpose

The purpose of this practicum is observed of giant chromosome at

Drosophila melanogaster larvae.

C. Benefit

The benefit of this practicum is we can know shape and the parts of giant

chromosome at Drosophila melanogaster larvae.

CHAPTER IIPREVIEW OF LITERATURE

There are chromosomes which are extremely large compared to normal

chromosomes. Such chromosomes, called giant chromosomes occur in some animal

cells. The types of giant chromosome are lampbrush and polytene chromosomes.

Lampbrush Chromosomes Polytene Chromosomes.

At lampbrush chromosomes these chromosomes occur in the oocytes (germ cells in

the ovary) of amphibians and in some insects. They are extremely large synapsed

homologous chromosomes which can be seen in the diplotene stage of prophase-I in

meiosis. They measure about 1500 to 2000 in length. A lampbrush chromosome

consists of an axis from which paired loops extend in opposite directions, giving the

appearance of a lamp brush. The axis consists of chromomeres (nucleosomes) and

interchromomere regions. The loops consist of transcriptional active DNA which can

synthesize large amount of mRNA, necessary for the synthesis of yolk. Polytene

chromosomes these are giant chromosomes found in the salivary gland cells of the

fruitfly Drosophila. They are many times larger than the normal chromosomes

reaching a length of 2000 and are visible even under a compound microscope.

The polytene chromosomes appear to contain five long and one short arm radiating

from a central point called chromocentre. It is formed by the fusion of centromeres of

all the eight chromosomes found in the cell. (Anonyma, 2009).

To increase cell volume, some specialized cells undergo repeated rounds of

DNA replication without cell division (endomitosis), forming a giant polytene

chromosome. Polytene chromosomes form when multiple rounds of replication

produce many sister chromatics that remain synapse together. In addition to

increasing the volume of the cell's nuclei and causing cell expansion, polytene cells

may also have a metabolic advantage as multiple copies of genes permits a high level

of gene expression. In Drosophila melanogaster, for example, the chromosomes of

the larval salivary glands undergo many rounds of endoreplication, to produce large

amounts of glue before pupation. Polytene chromosomes have characteristic light and

dark banding patterns which can be used to identify chromosomal rearrangements and

deletions. Dark banding frequently corresponds to inactive chromatin, while light

banding is usually found at areas with higher transcriptional activity. The banding

patterns of the polytene chromosomes of Drosophila melanogaster were sketched in

1935 by Calvin B. Bridges, in such detail that his maps are still widely used today.

The banding patterns of the chromosomes are especially helpful in research, as they

provide an excellent visualization of transcriptional active chromatin and general

chromatin structure (Anonymb, 2009).

At the high level organism, somatic cells (body cells, except sex cells)

contain one pack of cells that receive from the parental. The chromosome from the

female parental has form that similar from male parental. So that the pair of this

chromosome called homolog chromosome. So that the numbers of chromosome in

the body cells called diploid (2n). Sex cells (gamete) just contain a half from the

chromosome number that found in the somatic cells, because the number of

chromosome in the gamete called haploid (n). One pack of haploid chromosome in

the species called genome. Chromosome divided between autosom (body

chromosome) and sex chromosome. Fruitfly (Drosophila melanogaster) that usually

used to observation of genetic have 8 chromosomes that consist of 6 autosom and 2

sex chromosomes (Suryo, 2005).

Genome is the term used to describe the sum total of all the genes in one

haploid set of chromosomes. Sum total at every somatic cells same with all of group

species. Like human somatic cells contain 46 chromosomes, tobacco cells contain 48,

cow 60, Pisum sativum 14 and Drosophila melanogaster 8 chromosomes.

Chromosome arranged from DNA that associated with several kinds of protein. DNA

complex ant it protein usually see in the cell as chromatin (namely like that because it

complex easy given of color with colorations). The groups member of protein called

histon, can organized the chain of DNA long become a structure that usually called

nucleosomes. Centromeres that divide of chromosome become two arms that have

long variety, there are or not and the area place that large called chromomeres, there

are or not of length in the tip part chromatin called satellite (Elrod, 2007).

Chromosome base of centromeres place consist of metasentric, if the

centromeres place in the central, divide the both arm chromosome (p arm and q arm)

same long. Submetasentric, if the centromeres divide chromosome arm not same

long, p arm shorter that q arm. Telosentric, if centromeres place in the top

chromosome, there are length that called satellite. Base of chromosome morphology,

know that every chromosome have pair chromosome that same of shape. The pair of

it chromosome called pair of homologous chromosome (Tim dosen Unhas, 2007).

The organism that choice by Morgan for experiment is fruitfly species

Drosophila melanogaster, kinds of insect that generally not dangerous and eater of

fungi at fruit. Fruitfly is insect that easy to multiply. One of breeding ca result

hundreds offspring, and new generation can multiply every two weeks. This

characteristic become organism fruitfly that correct for genetic experiment. The other

advantages from Drosophila melanogaster is this fruitfly just have four pairs

chromosome, can with easy divided through light microscope. Found three pairs

autosom chromosome and one pair sex chromosome. The female fruitfly have one

pair X chromosome that homologue, than the male fruitfly have one chromosome X

and one Y chromosome (Campbell, 2002).

CHAPTER IIIPRACTICUM METHOD

A. Time and Place

Day / Date : Monday / November 16th 2009

Time : At 13.20 until at 14.20 pm

Place : Laboratory FMIPA Biology department floor II west part Makassar

State University (UNM)

B. Tools and Materials

1. Tools

a. Microscope

b. Object glass and deck glass

c. Pincer

d. Bunsen burner

e. Cutter

f. Petri dish

2. Materials

a. Drosophila melanogaster larvae

b. NaCl physiology

c. Aceto carmine

d. Aquades

C. Work Procedures

1. Took Drosophila melanogaster larvae, soaked in the NaCl physiology.

2. Lifted of larvae and leaked, then soaked in the aquades.

3. Then cut anterior part, put in the object glass, pressed and closed with deck

glass.

4. Filled aceto carmine in the peripheral part of deck glass and fixation.

5. Observed in under microscope.

CHAPTER IVOBSERVATION RESULT AND DISCUSSION

A. Observation result

Drosophila melanogaster larvae

Giant chromosome at Drosophila melanogaster larvae Explanations:

1. Arm

2. Centromeres

3. Chromatic

4. Satellite

5. Dark band

6. Light band

B. Discussion

At this observation we observated with using Drosophila melanogaster

larvae. Where the anterior part of larvae is cut and then soaked in NaCl

physiology then in the aquades and next given aceto carmine. The function of

NaCl physiology is to easy pressed of larvae and function of aceto carmine is

given of color at larvae until the chromosome is clear if see in under microscope.

Then the function from fixation is attached of deck glass at object glass.

At this observation we use Drosophila melanogaster larvae because its

have chromosome just four pairs chromosome, until with can easy to observated

in under microscope. Base observation we can found giant chromosome at

Drosophila melanogaster larvae and its parts. There are centromeres, arm

chromosome and satellite. Giant chromosome is chromosome that active to

fission without joined cells fission. The giant chromosome has the different size

with normal body chromosome. At the giant chromosome have longer

chromosome than normal body chromosome. At observation we can see there are

light area and dark area, this match with theory that said giant chromosome

consisting of dark band and light band.

These are giant chromosomes found in the salivary gland cells of the fruitfly

Drosophila. They are many times larger than the normal chromosomes reaching a

length of 2000 and are visible even under a compound microscope. The

polytene chromosomes appear to contain five long and one short arm radiating

from a central point called chromocentre. It is formed by the fusion of

centromeres of all the eight chromosomes found in the cell. Of the 6 arms, the

short arm represents the fused IV chromosome and the longest represents the

fused sex chromosomes. These arms contain numerous chromonemata resulting

from repeated replication of DNA, without separation into daughter

chromosomes. The arms show characteristic dark bands and light bands. The dark

bands are euchromatic regions. Some of the dark bands temporarily swell up and

form enlargements called chromosomal puffs or Balbiani rings. These regions

contain actively transcribing DNA involved in the synthesis of RNA types.

Polytene chromosomes are a peculiarity of rather unspecialized cells. They

occur in some animal and plant groups (e. g. in some dipteran species, in protozoa

and beans). Normal chromosomes consist of one or two, polytene chromosomes

of a whole range of chromatides (around 1000). The polytene character is kept

during interphase. Often, but not always, are homologous chromosomes paired (in

Drosophila, for example). The X-chromosome of the males is easily spotted,

since it has only half the thickness of the others due to the missing homologous

chromosome.

All polytene chromosomes of Drosophila are connected at their

centromeres. The centromeres domains are strongly heterochromatic and are also

called chromocenters. Polytene chromosomes can be recognized by their clear

and regular bands, the pattern is highly specific. In Drosophila , every band has

been identified, classified and numbered. The bands of the polytene chromosomes

have nothing to do with the bands of ordinary chromosomes about which we have

just talked. They can be seen without any staining. The bands of normal

chromosomes however are a kind of artifact they can only be observed after

staining. Polytene chromosomes became a suitable specimen for the study of

changes of the chromosomal structure and its consequences.

The salivary gland cells in the larvae stages of Drosophila contain large,

multistranded polytene chromosomes. Polytene chromosomes are produced by

repeated replication during synapsis without separation into daughter nuclei. This

laboratory procedure outlines the mechanism by which salivary glands are

removed and prepared so that the polytene chromosomes may be observed.

Drosophila virilis is used instead of Drosophila melanogaster because D. virilis is

much larger and it is easier to dissect and remove the salivary glands from the

larvae of this species.

CHAPTER VCONCLUSION AND SUGGESTION

A. Conclusion

Giant chromosome is chromosome that active to fission without joined

cells fission. At Drosophila melanogaster larvae there are found giant

chromosome with it parts like satellite, centromeres, chromatic, dark band, light

band and arm chromosome. Giant chromosome at larvae Drosophila

melanogaster have longer size.

B. Suggestion

1. Hoped to the practicing must active and attend the explain from assistant

about giant chromosome at Drosophila melanogaster larvae until don’t

happen mistake.

2. The tools that use must clear like microscope so that we can get result is be

better.

3. Hoped to assistant must guidance of practicing do observated until not happen

mistake.

BIBLIOGRAPHY

Anonyma, 2009. Giant Chromosomes. http://www/Autorvista.com/sitemap.php. Acessed at November 20th2009.

Anonymb. 2009. Politone Chromosome. http:// www.wikipedia.com Accessed at November 20th2009.

Campbell, Reeche, Mitchell. 2002. Biologi Jilid I Edisi Ke Lima. Jakarta. Erlangga. Suryo. 2005. Genetika Strata 1. Yokyakarta. Gajah Mada University Press.

Elrod, Susan. 2007. Genetika Edisi Ke Empat. Jakarta. Erlangga.

Tim dosen Unhas. 2007. Biologi Dasar. Makassar. Bidang Biologi Program TPB-Unhas