cell division cancer癌症和细胞分裂
合集下载
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
chromosomes
© 2003 Johg 2.4 The structure of a highly condensed, replicated chromosome.
A Chromosome
BASIC GENETICS
• Each cell in the human body contains two sets of 23 chromosomes
Mitotic centre
A cell at metaphase
Microtubule
a spindle
Chromosomes attached to spindle during nuclear division
INTERPHASE
After a cell has divided, the two new cells begin the process again, the cells at this stage are in Interphase.
One of life’s solutions to this challenge: “Package” the bits of information into single units called chromosomes
= one bit of genetic information
Packaging of genetic material in prokaryotes and eukaryotes prokaryote cell eukaryote cell
I
II
III
IV
The information transfer problem becomes more challenging as more bits of information are incorporated into the organism
= one bit of genetic information
Reproduction: Not as simple as it loo
Reproduction presents a major problem for cells and organisms: (how can information be transmitted faithfully to progeny) = one bit of genetic information
• As this is happening the nucleolus begins to break down
• The centrioles move to opposite ends of the nucleus.
• Nuclear membrane begins to break down
Diagram showing the Stages of Mitosis
Cytokinesis
Thus enabling the body to continuously make new body tissue for
growth and repair.
Prophase Metaphase
Anaphase
Prophase
• Chromatin condenses (remember that chromatin/DNA replicate during Interphase), the nuclear envelope dissolves, centrioles (if present) divide and migrate, the spindle forms.
The cell cycle.
© 2003 John Wiley and Sons Publishers
The Stages of the Cell Cycle
Mitosis
M stage
Mitotic Stage
The nucleus and cytoplasm split to make two new cells
• Mitosis identically replicates this information
• Each cell therefore has the same genetic material
• Reproductive cells only have one set of chromosomes. These combine to make a new person with different genetic material to both parents
The Stages of
Mitosis
Interphase
Telophase
The Spindle
A spindle is a web type structure made up of microtubule fibres. It is essential for mitosis because it arranges the chromosomes into their correct positions in preparation for cell division.
It is divided into three mini stages:-
G1
S
Cell cycle
G2
Eukaryotic chromsome replicating
PROPHASE
• The chromatin (unravelled DNA) in the nucleus, condenses to form pairs of chromosomes.
known as DIPLOID cells
STAGES OF MITOSIS
Every dividing tissue cell in the body is always at a stage of the cell cycle. Whether it is at :-
Interphase Prophase Metaphase Anaphase Telophase
© 2003 Johg 2.4 The structure of a highly condensed, replicated chromosome.
A Chromosome
BASIC GENETICS
• Each cell in the human body contains two sets of 23 chromosomes
Mitotic centre
A cell at metaphase
Microtubule
a spindle
Chromosomes attached to spindle during nuclear division
INTERPHASE
After a cell has divided, the two new cells begin the process again, the cells at this stage are in Interphase.
One of life’s solutions to this challenge: “Package” the bits of information into single units called chromosomes
= one bit of genetic information
Packaging of genetic material in prokaryotes and eukaryotes prokaryote cell eukaryote cell
I
II
III
IV
The information transfer problem becomes more challenging as more bits of information are incorporated into the organism
= one bit of genetic information
Reproduction: Not as simple as it loo
Reproduction presents a major problem for cells and organisms: (how can information be transmitted faithfully to progeny) = one bit of genetic information
• As this is happening the nucleolus begins to break down
• The centrioles move to opposite ends of the nucleus.
• Nuclear membrane begins to break down
Diagram showing the Stages of Mitosis
Cytokinesis
Thus enabling the body to continuously make new body tissue for
growth and repair.
Prophase Metaphase
Anaphase
Prophase
• Chromatin condenses (remember that chromatin/DNA replicate during Interphase), the nuclear envelope dissolves, centrioles (if present) divide and migrate, the spindle forms.
The cell cycle.
© 2003 John Wiley and Sons Publishers
The Stages of the Cell Cycle
Mitosis
M stage
Mitotic Stage
The nucleus and cytoplasm split to make two new cells
• Mitosis identically replicates this information
• Each cell therefore has the same genetic material
• Reproductive cells only have one set of chromosomes. These combine to make a new person with different genetic material to both parents
The Stages of
Mitosis
Interphase
Telophase
The Spindle
A spindle is a web type structure made up of microtubule fibres. It is essential for mitosis because it arranges the chromosomes into their correct positions in preparation for cell division.
It is divided into three mini stages:-
G1
S
Cell cycle
G2
Eukaryotic chromsome replicating
PROPHASE
• The chromatin (unravelled DNA) in the nucleus, condenses to form pairs of chromosomes.
known as DIPLOID cells
STAGES OF MITOSIS
Every dividing tissue cell in the body is always at a stage of the cell cycle. Whether it is at :-
Interphase Prophase Metaphase Anaphase Telophase