Cell Division Chapter 6 Flashcards
(25 cards)
What are the stages in cell division
Cytokinesis
Karyokinesis
What are the function of cytokinesis and karyokinesis?
Karyo: Division of Nucleus
Cyto: Division of cytoplasm
What are the organism’s body cell divided into?
Somatic cells and gametes
What are gametes?
- Reproductive cells
- Produced through Meiosis
- Contains a haploid number of chromosomes ( 23 ) , that is each cell contains one set of chromosomes
What are somatic cells?
- Body cells apart from gametes
- Produced through mitosis
- Contains a diploid number of chromosomes, that is each cell contains two set of chromosomes
What are the pairs of chromosomes present in cells called?
Homologous chromosomes
What are the chromosomes from the male parent called?
Paternal chromosomes
What are chromosomes from the female parent called?
Maternal Chromosomes
What does the cell cycle consist of?
Interphase and M phase
What is the cell cycle?
Sequence of events that involve DNA multiplication and cell division to produce 2 daughter cells
Which of the phases in cell cycle is the longest?
Interphase
What is the interphase made up of?
G1, G2 and S
What is the M phase made up of?
Mitosis and Meiosis
What is the function of the G1 phase during cell cycle
- Cell grows
- Cell components ( Mitochondrion ) are produced at this stage
- Proteins are synthesised during this time
- At this stage, nucleus looks big and chromosome is the form of chromatin
What is the function of the S phase during the cell cycle?
- DNA synthesis occurs
- DNA in the nucleus is replicated
- Each chromosomes multiplies into 2 identical chromosomes known as sister chromatids which contains the same copy of the DNA molecules and are joined at the centromere
What is the function of the G2 phase during cell cycle?
- Cells continue to grow and remain active metabolically
- Cells gather energy and make final arrangements to enter the next stage of cell division
- After this, cell enters M phase
What is mitosis
Division of the nucleus of the parent cell into 2 nuclei.
Each nuclei contains the same number of chromosomes and genetic content with the nucleus of parent cell
What phases are in mitosis?
Prophase
Metaphase
Anaphase
Telophase
What goes on during the prophase of the mitosis?
- Chromatin starts to shorten and thicken to form a chromosome structure
- Each chromosome is made up of 2 identical threads known as sister chromatids
- Nucleus membrane disintegrates, nucleolus disappears, centriole start to move towards opposite poles and spindle fiber start to form
What goes on during the metaphase of mitosis
- Centrioles are at opposite poles of the cell
- Spindle fiber maintain the chromosomes at the equatorial plane are are aligned in a single row
- Metaphase ends when centromere starts to divivde
What goes on during the anaphase of mitosis?
- Centromere divides into two and sister chromatids separate
- Spindle fibers shorten, contract and sister chromatids are pulled to the opposite poles of the cell
- Anaphase ends when chromatids arrives at the pole of the cell
What goes on during the telophase of mitosis
- When chromatids are at opposite poles, they are now called daughter chromosome
- Each pole contains one set of complete and identical chromosomes
- Chromosomes re-form as fine chromatin threads
- Nucleoli are formed again
- Spindle fibers disappear
- New nucleus membrane is formed
- Cytokinesis follows
How does cytokinesis occur in animal cells?
- When the plasma membrane constricts in the middle of the cell between 2 nuclei
- Microfilaments at the point of constriction contract. causing the cell to constrict and split to form 2 daughter cells
How does cytokinesis occur in plant cells?
- Formed vesicles combine to form cell plates at the centre of the cell
- Cell plates are surrounded by new plasma membrane and a new cell wall substance is formed among the spaces of the cell plates
- The cell plates expand outwards until they combine with the plasma membrane
