REPRODUKSI • Reproduksi merupakan sarana makhluk hidup untuk mempertahankan eksistensinya • Reproduksi: – Reproduksi Sel – Reproduksi Tumbuhan – Reproduksi Hewan dan Manusia
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
REPRODUKSI SEL • Sel merupakan unit struktural dan fungsional terkecil dalam hierarki kehidupan • Sel mengalami proses pertumbuhan, perkembangan dan perbanyakan. – Pertumbuhan: Ukuran – Perkembangan: Fungsi – Perbanyakan: Jumlah
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
REPRODUKSI SEL • Tiga macam cara reproduksi tingkat sel: – Amitosis – Mitosis – Meiosis
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
AMITOSIS 100 µm
(a) Reproduction. An amoeba, a single-celled eukaryote, is dividing into two cells. Each new cell will be an individual organism (LM).
Figure 12.2 A
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
AMITOSIS • Pembelahan sel tanpa melalui tahapan khusus. • Dilakukan dengan proses kariokinesis langsung dilanjutkan dengan sitokinesis • Digunakan sebagai cara perkembangbiakan oleh organisme tingkat rendah. • Amitosis = Pembelahan biner = Pembelahan spontan Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
Pembelahan Biner pada E. coli Origin of replication
Cell wall
E. coli cell Two copies of origin
Origin
Priyambodo, M.Sc.
Plasma Membrane Bacterial Chromosome
Origin
Biologi Umum
Sistem Reproduksi Makhluk Hidup
MITOSIS DAN MEIOSIS • Merupakan pembelahan sel dengan melalui tahapan khusus – Interfase • G1 • S • G2
– Fase mitotik • • • • •
Profase Metafase Anafase Telofase Sitokinesis Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
SIKLUS SEL INTERPHASE
S (DNA synthesis)
G1
G2
Figure 12.5
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
MITOSIS • Pembelahan sel tanpa adanya reduksi jumlah kromosom • Terjadi pada sel-sel somatis • Dalam satu kali mitosis hanya sekali terjadi pembelahan (fase mitotik) • Fungsi: Pertumbuhan, Perbaikan
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
MITOSIS
G2 OF INTERPHASE Centrosomes (with centriole pairs)
Figure 12.6
Nucleolus
Nuclear envelope
Chromatin (duplicated)
Plasma membrane
Priyambodo, M.Sc.
PROMETAPHASE
PROPHASE
Early mitotic spindle
Aster Centromere
Chromosome, consisting of two sister chromatids
Biologi Umum
Fragments of nuclear envelope
Kinetochore Nonkinetochore microtubules
Kinetochore microtubule
Sistem Reproduksi Makhluk Hidup
MITOSIS
METAPHASE
ANAPHASE
Metaphase plate
Figure 12.6
Spindle
Centrosome at one spindle pole
Priyambodo, M.Sc.
TELOPHASE AND CYTOKINESIS
Cleavage furrow
Daughter chromosomes
Biologi Umum
Nucleolus forming
Nuclear envelope forming
Sistem Reproduksi Makhluk Hidup
MITOSIS PADA SEL TUMBUHAN Chromatine Nucleus Nucleolus condensing
Chromosome
Metaphase. The 2 Prometaphase. 3 1 Prophase. spindle is complete, 4 The chromatin We now see discrete and the chromosomes, is condensing. chromosomes; each attached to microtubules The nucleolus is consists of two at their kinetochores, beginning to identical sister are all at the metaphase disappear. chromatids. Later plate. Although not in prometaphase, the yet visible nuclear envelop will in the micrograph, fragment. the mitotic spindle is staring to from.
Anaphase. The 5 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.
Figure 12.10
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
Sitokinesis pada sel hewan
Cleavage furrow
Contractile ring of microfilaments
Figure 12.9 A
100 µm
Daughter cells
(a) Cleavage of an animal cell (SEM)
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
Sitokinesis pada sel tumbuhan
Vesicles forming cell plate
Figure 12.9 B
Priyambodo, M.Sc.
Wall of patent cell
1 µm
Cell plate
New cell wall
Daughter cells (b) Cell plate formation in a plant cell (SEM)
Biologi Umum
Sistem Reproduksi Makhluk Hidup
MEIOSIS • Pembelahan sel disertai adanya reduksi jumlah kromosom • Terjadi pada sel-sel gamet • Dalam satu kali meiosis terjadi dua kali pembelahan (fase mitotik) • Fungsi: Reproduksi organisme tingkat tinggi
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
Interphase Homologous pair of chromosomes in diploid parent cell
MEIOSIS
Chromosomes replicate Homologous pair of replicated chromosomes
Sister chromatids
Diploid cell with replicated chromosomes
Meiosis I
1 Homologous chromosomes separate
Haploid cells with replicated chromosomes Meiosis II 2 Sister chromatids separate
Figure 13.7
Priyambodo, M.Sc.
Haploid cells with unreplicated chromosomes
Biologi Umum
Sistem Reproduksi Makhluk Hidup
• Interphase and meiosis I MEIOSIS I: Separates homologous chromosomes
INTERPHASE
PROPHASE I
METAPHASE I
ANAPHASE I
Sister chromatids remain attached
Centromere (with kinetochore)
Centrosomes (with centriole pairs) Sister chromatids
Chiasmata Spindle
Metaphase plate
Nuclear envelope
Homologous Microtubule chromosomes Tetrad attached to Chromatin separate kinetochore Pairs of homologous Chromosomes duplicate Tertads line up chromosomes split up Homologous chromosomes (red and blue) pair and exchange segments; 2n = 6 in this example
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
Meiosis I
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
• Telophase I, cytokinesis, and meiosis II MEIOSIS II: Separates sister chromatids TELOPHASE I AND CYTOKINESIS
METAPHASE II
PROPHASE II
Cleavage furrow
Figure 13.8
Two haploid cells form; chromosomes are still double
ANAPHASE II
Sister chromatids separate
TELOPHASE II AND CYTOKINESIS
Haploid daughter cells forming
During another round of cell division, the sister chromatids finally separate; four haploid daughter cells result, containing single chromosomes
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
Oogenesis dan Spermatogenesis
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
Perbandingan Mitosis dan Meiosis MITOSIS
MEIOSIS Chiasma (site of crossing over)
Parent cell (before chromosome replication)
MEIOSIS I
Prophase I
Prophase Chromosome replication Duplicated chromosome (two sister chromatids)
Chromosome replication
Tetrad formed by synapsis of homologous chromosomes
2n = 6
Metaphase
Chromosomes positioned at the metaphase plate
Anaphase Telophase
Sister chromatids separate during anaphase
2n
Tetrads positioned at the metaphase plate
Homologues separate during anaphase I; sister chromatids remain together
Metaphase I
Anaphase I Telophase I Haploid n=3
Daughter cells of meiosis I
2n
MEIOSIS II
Daughter cells of mitosis n
n
n
n
Daughter cells of meiosis II Sister chromatids separate during anaphase II
Figure 13.9
Priyambodo, M.Sc.
Biologi Umum
Sistem Reproduksi Makhluk Hidup
