11.2 The cell cycle and mitotic cell division
Ø New cells can be
produced by (1) cell division
Ø
During the process of cell division,
n
a (2) parent cell divides into two or more new cells
called (3)daughter cells
n the (4)genetic
information of the parent cell passes to the daughter cells.
This information
determines the cellular structure and function, and is carried by (5)DNA
Ø
Many body
cells can divide by (6)mitotic cell division (有絲細胞分裂).
Ø The sequence of
events that takes place in a body cell from one cell division to the next is
called
(7)
cell cycle (細胞週期)
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A
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What are the stages of the cell cycle?(Book 2, p. 11-6)
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Stage
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Description
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(8) Interphase (間期)
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It is also
called cell growth.
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Mitotic cell division
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It consists of (9)nuclear
division and (10)cytoplasmic division.
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1 Interphase
(間期) (cell growth)
n
Many biochemical activities take place to prepare for cell division, including:
l synthesisof new
(11) organelles
and proteins.
l DNA (12) replicates (複製). Each chromosome becomes
duplicated (複製)
and it consists of (13) two
identical DNA
molecules.
l the growth of
cell to its (14) maximum size.
n
Chromosomes are (15) visible / invisible at
this stage.
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2 Mitotic
cell division (有絲細胞分裂)
n A body cell divides to form (16) two
daughter cells.
n
The daughter cells contain the same (17) numbers and (18) types of chromosomes as their
parent cell.
i) Nuclear division (核分裂)
l The nuclear
division of mitotic cell division is called (19) mitosis (有絲分裂). It involves:
² the separation of the (20) sister
chromatids of each chromosomes
²
the equal (21)
distribution
of the separated chromatids between two daughter nuclei, so that each
daughter nucleus obtains a complete set of chromosomes
l
The produced nuclei are (22) diploid (2n) (same as the
parent cell)
l Mitosis can be
divided into four stages:
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Stage
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Description
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1.
(23)
Prophase (前期)
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l Chromosomes shorten and thicken.
They become (24) visible / invisible
l Two chromatids link together at
(25) centromere, forming the
chromosome.
l
The
(26) nuclear
membrane breaks down.
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2.
(27)
Metaphase
(中期)
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l The chromosomes
line up along the
(28) equator
l (29)spindle fibres (紡錘絲)attach to the
chromosomes.
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3.
(30)
Anaphase
(後期)
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l The spindle fibres(31)
contract.
l The (32) chromatid
separates and move to opposite poles of the cell.
l The (33)cytoplasm
start to divide.
èSeparation of chromosomes
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4.
(34) Telophase (末期)
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l
New (35) nuclear membrane form around
each group of chromosomes.
l The chromosomes
uncoil展開 to become
(36) chromatins
again.
èProcess of mitotic division
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ii) Cytoplasmic division (胞質分裂)
l
is also called (37) cytokinesis (胞質分裂).
l takes place near
the end of the mitosis.
l
The (38) cytoplasm of the parent cell divides into two equal halves, forming
two daughter cells.
l In animal cells,the cell membrane around the centre of the cell (39) contracts inwards until the cell separates into two.
l In plant cells, a (40) cell plate (細胞板) is formed between the two daughter
nuclei and grows outwards from the
centre of the cell, dividing the (41) cytoplasm into two halves.
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B
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What is the importance of mitotic cell division?(Book
2, p. 11-11)(CE-2006-I-A Q.4)
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Ø Mitotic cell
division produces daughter cells that
are genetically(42) identical to
/ different from their parent cell.
Ø Mitotic cell
division is important for:
n (43) growth:
providing new cells for multicellular organism;
n (44) repair:
providing new cells to replace dead or damaged cells;
n (45) asexual reproduction(無性生殖).
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