Este documento proporciona una introducción al ciclo celular y la división celular. Explica las diferentes fases del ciclo celular, incluida la interfase y la mitosis. Describe los eventos que ocurren durante cada fase de la mitosis y cómo el huso mitótico controla el movimiento de los cromosomas. También cubre la organización del material genético en células procariotas y eucariotas, y los mecanismos de división celular como la fisión binaria y la citocinesis.
26. Fig. 12-8
EXPERIMENT
Kinetochore
Spindle
pole
Mark
RESULTS
CONCLUSION
Chromosome
movement
Kinetochore
Motor Tubulin
Microtubule protein subunits
Chromosome
48. Fig. 12-13
EXPERIMENT
Experiment 1 Experiment 2
S G1 M G1
RESULTS
S S M M
When a cell in the When a cell in the
S phase was fused M phase was fused with
with a cell in G1, the G1 a cell in G1, the G1
nucleus immediately nucleus immediately
entered the S began mitosis—a
phase—DNA was spindle formed and
synthesized. chromatin condensed,
even though the
chromosome had not
been duplicated.
55. Fig. 12-17
M G1 S G2 M G1 S G2 M G1
MPF activity
Cyclin
concentration
Time
(a) Fluctuation of MPF activity and cyclin concentration during
the cell cycle
S
Cyclin accumulation
G1
Cdk
M
Degraded G2
cyclin
G2 Cdk
Cyclin is checkpoint
degraded
Cyclin
MPF
(b) Molecular mechanisms that help regulate the cell cycle
56. Fig. 12-17a
M G1 S G2 M G1 S G2 M G1
MPF activity
Cyclin
concentration
Time
(a) Fluctuation of MPF activity and cyclin concentration during
the cell cycle
57. Fig. 12-17b
Cyclin accumulation
1
S
G
Cdk
M
Degraded G2
cyclin
G2 Cdk
Cyclin is checkpoint
degraded
Cyclin
MPF
(b) Molecular mechanisms that help regulate the cell cycle
65. Fig. 12-20
Lymph
vessel
Tumor
Blood
vessel
Cancer
Glandular
cell
tissue Metastatic
tumor
1 A tumor grows 2 Cancer cells 3 Cancer cells spread 4 Cancer cells may
from a single invade neigh- to other parts of survive and
cancer cell. boring tissue. the body. establish a new
tumor in another
part of the body.
66. Fig. 12-UN1
G1 S
Cytokinesis
Mitosis G2
MITOTIC (M) PHASE
Prophase
Telophase and
Cytokinesis
Prometaphase
Anaphase
Metaphase