Biology
Prophase
Chromatin condenses to form chromosomes. Centrioles migrate to opposite poles of the cells (except in plant cells which do not have centrioles). Microtubules develop and form a star shaped structure known as an aster, and spindle fibres may develop. Nucleolus disappears, and the nuclear membrane disintegrates.
Metaphase
During this phase, the chromosomes arrange themselves at the equator of the cell, and they are attached to the spindle fibres at the centromere. Each chromosome is still composed of two chromatids.
Anaphase
During this phase, each centromere duplicates and the spindle fibres contract or shorten further. This causes the chromatids of each chromosome to separate and migrate to opposite poles, led by the centromeres. The shortening of the spindle fibres is due to the progressive removal of the tubulin molecules of which they are made.
Telophase
Chromatids reach their respective poles and a new nuclear envelope forms around each group. Chromatids uncoil and lengthen. The spindle fibres disintegrate and a nucleolus reforms again in each nucleus. A new cell membrane is formed. In the case of plants, a new cell wall also forms.
Cytokinesis subsequently occurs.
- Q: Explain How Mitosis Ensures That Cells Are Genetically Identical
During S phase of interphase, semi-conservative replication of DNA occurs. Complementary base pairing rules are adhered to (on complementary strands, A is paired with T; C is paired with G). During anaphase, sister chromatids are separated and move to...
- Structure And Functions Of Organelles
The nucleus is bound by two membranes known as the nuclear envelope, which has perforations called nuclear pores. Chromatin within the nucleus condenses to form chromosomes during cell division. The nucleus controls all cellular activity. During mitosis,...
- The Cell Cycle
What are all of the stages to the Cell Cycle? The Cell Cycle starts with its first stage called Interphase. The cell will be in this stage the longest amount of time out of all of the stages of the cycle. During the first part of Interphase is called...
- #80 Question 3
(a) The diagrams show a cell in various stages ofthe mitotic cell cycle. Name the stage represented by each diagram, and arrange them in the correct sequence. (b) Describe the role of spindle microtubules in mitosis. (3 marks) (c) The graph below shows...
- #32 Summary Of Cell And Nuclear Division
1. Growth of a multicellular organism is a result of parent cells dividing to produce genetically identical daughter cells. 2. During cell division the nucleus divides first, followed by division of the whole cell. 3. Division of a nucleus to produce...
Biology
Mitosis
Prophase
Chromatin condenses to form chromosomes. Centrioles migrate to opposite poles of the cells (except in plant cells which do not have centrioles). Microtubules develop and form a star shaped structure known as an aster, and spindle fibres may develop. Nucleolus disappears, and the nuclear membrane disintegrates.
Metaphase
During this phase, the chromosomes arrange themselves at the equator of the cell, and they are attached to the spindle fibres at the centromere. Each chromosome is still composed of two chromatids.
Anaphase
During this phase, each centromere duplicates and the spindle fibres contract or shorten further. This causes the chromatids of each chromosome to separate and migrate to opposite poles, led by the centromeres. The shortening of the spindle fibres is due to the progressive removal of the tubulin molecules of which they are made.
Telophase
Chromatids reach their respective poles and a new nuclear envelope forms around each group. Chromatids uncoil and lengthen. The spindle fibres disintegrate and a nucleolus reforms again in each nucleus. A new cell membrane is formed. In the case of plants, a new cell wall also forms.
Cytokinesis subsequently occurs.
- Q: Explain How Mitosis Ensures That Cells Are Genetically Identical
During S phase of interphase, semi-conservative replication of DNA occurs. Complementary base pairing rules are adhered to (on complementary strands, A is paired with T; C is paired with G). During anaphase, sister chromatids are separated and move to...
- Structure And Functions Of Organelles
The nucleus is bound by two membranes known as the nuclear envelope, which has perforations called nuclear pores. Chromatin within the nucleus condenses to form chromosomes during cell division. The nucleus controls all cellular activity. During mitosis,...
- The Cell Cycle
What are all of the stages to the Cell Cycle? The Cell Cycle starts with its first stage called Interphase. The cell will be in this stage the longest amount of time out of all of the stages of the cycle. During the first part of Interphase is called...
- #80 Question 3
(a) The diagrams show a cell in various stages ofthe mitotic cell cycle. Name the stage represented by each diagram, and arrange them in the correct sequence. (b) Describe the role of spindle microtubules in mitosis. (3 marks) (c) The graph below shows...
- #32 Summary Of Cell And Nuclear Division
1. Growth of a multicellular organism is a result of parent cells dividing to produce genetically identical daughter cells. 2. During cell division the nucleus divides first, followed by division of the whole cell. 3. Division of a nucleus to produce...