3. 100 µm
(a) Reproduction. An amoeba,
a single-celled eukaryote, is
dividing into two cells. Each
new cell will be an individual
organism (LM).
4. • Organisme multiseluler tergantung pada
pembelahan sel untuk:
– Perkembangan (dari sel yang terfertilisasi)-
reproduksi
– Pertumbuhan
– Repair
20 µm200 µm
(b) Growth and development.
This micrograph shows a
sand dollar embryo shortly
after the fertilized egg divided,
forming two cells (LM).
(c) Tissue renewal. These dividing
bone marrow cells (arrow) will
give rise to new blood cells (LM).
Figure 12.2 B, C
5. •Semua organisme
kompleks berasal dari a
single fertilized egg.
•Melalui pembelahan sel,
jumlah sel meningkat
•Sel kemudian
terspesialisasi dan
berubah menjadi
fungsinya masing2
6. Tipe pembelahan sel
• Mitosis:
– Growth, development & repair
– Asexual reproduction (yields identical cells)
– Occurs in somatic (body) cells
• Meiosis:
– Sexual reproduction (yields different cells)
– Occurs in specific reproductive cells
10. The Cell Cycle
1. G1
Phase 1st
growth phase
2. S Phase DNA duplicated
3. G2
Phase Final growth phase
4. Mitosis
5. Cytokinesis
Purpose of the first three phases (Interphase) – to duplicate
cell contents; 90% of the cell’s growth cycle (Sel tumbuh &
menyalin kromosom dalam persiapan untuk pembelahan sel)
Purpose of Mitosis – to divide the genetic material into exact
two halves (pembelahan nukleus)
Purpose of Cytokinesis – to divide all other contents (except
nucleus) into two cells. (pembelahan sitoplasma)
interphase
11. Interfase
1. G1
Phase 1st
growth phase; sel tumbuh
2. S Phase DNA duplicated; kromosom
diduplikasi
3. G2
Phase Final growth phase; tumbuh lagi
sampai sel menyelesaikan persiapannya untuk
pembelahan sel
Selama 3 subfase ini, sel tumbuh dengan
menghasilkan protein dan organel dalam
sitoplasma
12. Phases of Mitosis (M)
1. Prophase
2. Prometaphase
3. Metaphase
4. Anaphase
5. Telophase
• Pembelahan sel menghasilkan sel anak yang
secara genetik identik/sama
• Sel harus menduplikasikan material genetiknya
– Before they divide, ensuring that each daughter cell
receives an exact copy of the genetic material, DNA
13. Phases
of Mitosis
Hal-hal yang unik pada fase M
1.Kondensasi kromosom
2.Mitotic spindle
mengatur kromosom yang telah
direplikasi
- di ekuator
- ke kutub
3.Cincin kontraktil: filamen actin dan miosin
tegak lurus spindle
Menarik membran ke dalam
15. Distribution of Chromosomes During Cell
Division
• Pada persiapan cell division, DNA bereplikasi
dan kromosom memadat
• Tiap chromosome yang terduplikasi memiliki
dua sister chromatids, yang berpisah selama
cell division
• Sentromer merupakan daerah ceking dari
chromosome yang terduplikasi, dimana dua
chromatids terikat dengan erat
16. Pembelahan sel mendistribusikan
kumpulan sel yang identik ke sel anak
• Sel menduplikasikan material genetik sebelum
membelah, utk memastikan bahwa tiap sel
anak menerima copy DNA dengan tepat
• Karunia herediter keseluruhan, berisi DNA
yang dimiliki oleh suatu sel disebut genome
dari sel tersebut
• Molekul DNA dalam sel ter-pack menjadi
kromosom
17. • Setiap spesies eukariot memiliki sejumlah
tertentu kromosom pada nukleus
• Sel somatik (nonreproductive) memiliki 2 set
kromosom
• Gamet (reproductive cells: sperm and eggs)
memiliki jumlah kromosom setengah jumlah
kromosom sel somatik
• Kromosom eukaryotik terdiri dari kromatin,
sebuah komplex DNA dan protein yang
memampat selama pembelahan sel
18.
19. 0.5 µm
Chromosome
duplication
(including DNA
synthesis)
Centromere
Separation
of sister
chromatids
Sister
chromatids
Centromeres Sister chromatids
A eukaryotic cell has multiple
chromosomes, one of which is
represented here. Before
duplication, each chromosome
has a single DNA molecule.
Once duplicated, a chromosome
consists of two sister chromatids
connected at the centromere. Each
chromatid contains a copy of the
DNA molecule.
Mechanical processes separate
the sister chromatids into two
chromosomes and distribute
them to two daughter cells.
Figure 12.4
20. • Pembelahan sel pada eukariot terdiri dari:
– Mitosis, the division of the nucleus
– Cytokinesis, the division of the cytoplasm
• Gamet diproduksi dalam pembelahan sel yang
disebut meiosis
• Meiosis menghasilkan sel anak yang tidak
identik dengan induk yaitu hanya memiliki 1
set kromosom
21.
22. Fase-fase dalam siklus sel
• Siklus sel terdiri dari
– Interphase
– Fase mitosis
INTERPHASE
G1
S
(DNA synthesis)
G2
Cytokinesis
M
itosis
MITOTIC(M) PHASE
Figure 12.5
• Interphase
– G1 phase
– S phase
– G2 phase
• The mitotic phase
– mitosis
– cytokinesis
23. Phases of the Cell Cycle
• Siklus sel terdiri dari
– Interphase (cell growth and copying of
chromosomes in preparation for cell division)
– Mitotic (M) phase (mitosis and cytokinesis)
• Interphase (terdiri dari sekitar 90% dari siklus
sel) yang dapat dibagi dalam sub fase:
– G1 phase (“first gap”)
– S phase (“synthesis”)
– G2 phase (“second gap”)
24. • Mitosis terdiri dari 5 phases
– Prophase
– Prometaphase
G2 OF INTERPHASE PROPHASE PROMETAPHASE
Centrosomes
(with centriole pairs) ChromatinChromatin
(duplicated)(duplicated)
Early mitotic
spindle
Aster
Centromere
Fragments
of nuclear
envelope
Kinetochore
NucleolusNucleolus Nuclear
envelope
Plasma
membrane
Chromosome, consisting
of two sister chromatids
Kinetochore
microtubule
Nonkinetochore
microtubules
25. – Metaphase
– Anaphase
– Telophase
Centrosome at
one spindle pole
Daughter
chromosomes
METAPHASE ANAPHASE TELOPHASE AND CYTOKINESIS
Spindle
Metaphase
plate Nucleolus
forming
Cleavage
furrow
Nuclear
envelope
forming
26. • The mitotic spindle
– mikrotubul yang mengontrol pergerakan kromosom
selama mitosis
• Spindle muncul dari sentromer
– spindle microtubules
– asters
27. • Perakitan spindle microtubules dimulai dari
sentrosom - microtubule organizing center
• Sentrosom bereplikasi membentuk dua
sentrosom yang bermigrasi ke kutub yang
berlawanan, dan spindle microtubules tumbuh
dari sentrosom
• Aster (a radial array of short microtubules)
muncul dari tiap sentrosom
28. The SpindleThe Spindle
(benang gelendong)(benang gelendong)
Spindle memiliki struktur seperti web terbuat
dari microtubule . Sangat penting pada mitosis
karena mengatur kromosom untuk berada
pada posisi yang benar
Mitotic center
Microtubule
A cell at metaphase a spindle
30. Chromosomes attached to spindleChromosomes attached to spindle
during nuclear divisionduring nuclear division
31. The kinds of microtubules
• Kinetochore microtubules : berikatan dengan
kinetochores chromosomes dan menggerakkan kromosom
ke daerah metafase
• Nonkinetochores: overlap satu sama lain tetapi tidak
berikatan dengan chromosome
1 µm
32. Replikasi sentriol
Pada
G1 : 1 pasang sentriol terpisah
S : sentriol anak tumbuh
G2 : perpanjangan sentriol anak
Awal fase M : kedua pasang sentriol masih dekat,
kemudian terpisah
33. Siklus sentrosomSentrosom harus diduplikasi dan dipisahkan
Fase S dan G2: 2 ps
sentriol
Profase awal:
sentrosom membelah,
tiap anak menjadi
pusat mikrotubul
astral
Profase akhir:
mikrotubul polar
memanjang, 2
sentrosom terpisah
Metafase: mikrotubul
berinteraksi dg
kromosom, tidak ada
selubung nuklear
34. The Mitotic Spindle:
How chromosomes moved??
The mitotic spindle (structure, shape name)
– Is an apparatus of microtubules
(composition name) that controls
chromosome movement during mitosis
– Usually called by Spindle mocrotuble
35. How kinetochore microtuble works
• In anaphase, sister chromatids separate And
move along the kinetochore microtubules
toward opposite ends of the cell
EXPERIMENT
1 The microtubules of a cell in early anaphase were labeled with a fluorescent dye
that glows in the microscope (yellow).
Spindle
pole
Kinetochore
Figure 12.8
36. 2 A Laser was used to mark the kinetochore mircotubles by eliminating the fluorescnce in a region between
one spindle pole and the chromosomes. As anaphase proceeded, researches monitored the changes
in the lengths of the microtubles on either side of the mark.
Mark
RESULTS As the chromosomes moved toward the poles, the microtubule segments on the
kinetochore side of the laser mark shortened, while those on the spindle pole side stayed the
same length.
Discuss about the results
37. CONCLUSION This experiment demonstrated that during anaphase,
kinetochore microtubules shorten
at their kinetochore ends, not at their spindle pole ends. This is just
one of the experiments supporting the
hypothesis that during anaphase, a chromosome tracks along a
microtubule as the microtubule
depolymerizes at its kinetochore end, releasing tubulin subunits
Chromosome
movement
Microtubule
Motor
protein
Chromosome
Kinetochore
Tubulin
subunits
38. CONCLUSION dalam percobaan ini Selama anafase berlanjut dan
kromosom berpindah ke arah kutub, segmen mikrotubul pada sisi
kinetokor dari tanda laser memendek, sementara bagian sisi
sentromer tetap. Percobaan ini mendukung hipotesis bahwa;
kromosom menelusuri disepanjang mikrotubul pada saat mikrotubul
berdepolarisasi pada ujung kinetokornya, sehingga terjadi pelepasan
sub unit tubulin
Chromosome
movement
Microtubule
Motor
protein
Chromosome
Kinetochore
Tubulin
subunits
39. Tiga kelas
mikrotubul:
1.Mikrotubul polar :
mendorong kutub spindle
saling menjauh
2. Mikrotubul kinetokor:
berikatan dengan
kinetokor, mengatur
kromosom
3. Mikrotubul astral:
memancar ke seluruh
arah dari sentrosom
40. Yang melekat pada sentrosom : ujung –
ujung positif : dinamis, memanjang
memendek
overlap
Protein yang berasosiasi dengan mikrotubul, mengikat mikrotubul
41.
42. • Pada anafase, sister chromatid berpisah
– Dan bergerak sepanjang kinetochore microtubules
menuju arah berlawanan ujung sel
Spindle
pole
Kinetochore
Figure 12.8
46. CYTOKINESISCYTOKINESIS
Division of the cytoplasm
Mitosis is the splitting of the nucleus.
Cytokinesis is the splitting of cytoplasm
It usually begins during ANAPHASE
47. Sitokinesis
• Saat anafase berlanjut ke telofase
•Pada sel hewan : melekuknya selaput sel
kontraksi cincin contractil
• Pada sel tumbuhan : pembentukan dinding baru
Sekat sel di antara 2 sel anak
-sisa-sisa mikrotubul polar membentuk fragmoplast
-vesikuli kecil dari kompleks golgi berisi prazat
dinding sel
• Tempat sekat : telah ditentukan oleh mikrotubul pada
preprofase
48. • Pada sel hewan
– Cytokinesis terjadi oleh proses yang disebut
cleavage, membentuk sebuah a cleavage furrow
Cleavage furrow
Contractile ring of
microfilaments
Daughter cells
100 µm
(a) Cleavage of an animal cell (SEM)
49. • Pada sel tumbuhan, selama cytokinesis
– Terbentuk plat sel (cell plate)
Daughter cells
1 µmVesicles
forming
cell plate
Wall of
patent cell Cell plate New cell wall
(b) Cell plate formation in a plant cell (SEM)Figure 12.9 B
50. • Mitosis in a plant cell
1 Prophase.
The chromatin
is condensing.
The nucleolus is
beginning to
disappear.
Although not
yet visible
in the micrograph,
the mitotic spindle is
staring to from.
Prometaphase.
We now see discrete
chromosomes; each
consists of two
identical sister
chromatids. Later
in prometaphase, the
nuclear envelop will
fragment.
Metaphase. The
spindle is complete,
and the chromosomes,
attached to microtubules
at their kinetochores,
are all at the metaphase
plate.
Anaphase. The
chromatids of each
chromosome have
separated, and the
daughter chromosomes
are moving to the ends
of cell as their
kinetochore
microtubles shorten.
Telophase. Daughter
nuclei are forming.
Meanwhile, cytokinesis
has started: The cell
plate, which will
divided the cytoplasm
in two, is growing
toward the perimeter
of the parent cell.
2 3 4 5
Nucleus
Nucleolus
ChromosomeChromatine
condensing
Figure 12.10
51. • Mitosis in a plant cell
a. Profase= kromatin memadat, nukleolus masih jelas terlihat
tetapi akan segera menghilang, gelendong mitotik mulai
terbentuk
b. Prometafase= kromosom yang terpisah; masing-masing terdiri
atas dua kromatid saudara yang identik yang salin melekat.
Kemudiian seludang nukleus akan terfragmentasi dan
mikrotubula gelendong akan melekat pada kinetokor kromosom
c. Metafase= gelendong telah lengkap, dan kromosom yang
ditarik sama kuat oleh mikrotubula kinetokor yang datang dari
kutub sel yang berlawanan, berbaris pada pelat metafase
d. Anafase= kromatid setiap kromosom telah terpisah dan
kromosom anak berpindah ke kutub-kutub sel begitu
mikrotubula kinetokornya memendek
e. Telofase= nukleus anak terbentuk, sementara itu sitokinesis
mulai terjadi; pelat sel , yang akan membagi sitoplasma
menjadi 2, sedang tumbuh ke arah keliling sel induknya
52. In binary fission
– The bacterial chromosome
replicates
– The two daughter
chromosomes actively move
apart
Prokaryotes (bacteria and archaea) reproduce
by a type of cell division called binary fission
53. LE 12-11_3
Origin of
replication
Cell wall
Plasma
membrane
Bacterial
chromosome
E. coli cell
Two copies
of origin
Chromosome
replication begins.
Soon thereafter,
one copy of the origin
moves rapidly toward
the other end of the
cell.
Replication continues.
One copy of the origin
is now at each end of
the cell.
Origin Origin
Replication finishes.
The plasma membrane
grows inward, and
new cell wall is
deposited.
Two daughter
cells result.
56. Tugas
Gambar Perbedaan fase mitosis dan miosis
Setelah melihat FLASH mitosis dan Meiosis ini
Contoh flash meiosis lainnya
Editor's Notes
So far, I’ve been talking about mitosis only
What? Somatic (body) cells
Why? Growth & development, repair lost or injured cells
Allows many organisms to reproduce asexually
But there is a 2nd type of cell division - meiosis that occurs only in select cells within certain tissue at particular phases of an organism’s lifetime.
meiosis is involved with organisms that undergo SEXUAL REPRODUCTION
--means of reducing number of chromosomes in sperm or egg so when combined through fertilization, the original number is restored
-- reduction of genetic state from diploidy to haploidy necessary
--occurs in reproductive organs in humans -- ovary & testis -- produces haploid cells called gametes (sperm, egg)
--completed with fertilization of male gamete & female gamete to produce diploid zygote
Fig. 19.1, p. 345: cartoon (left), EM (right)
Chromatin = helix wrapped around protein -- giving bead-like structure
These proteins are called ‘histones’
Nucleosome = DNA + histone complex
Chromatin = a string of these beads (thread-like)
Chromosome = looped and compacted chromatin
Click the return button to return to the prophase slide. Or the house button to return to the main menu.
The purpose of the spindle is to organise the chromosomes during mitosis. It is a cradle of microtubule fibres which cause constriction around the centre of the cell, causing the cytoplasm to split.