1.6 cell division Flashcards
Binary fission
A type of asexual reproduction common among prokaryotes where one cell divides giving rise to two cells, each having the potential to grow to the size of the original cell [this is not mitosis].
Mitosis
The division of the nucleus into two genetically identical daughter nuclei.
Interphase
A very active phase of the cell cycle, when the cell is not in mitosis.
The cell cycle
The sequence of events between one cell division and the next.
Centriole
A self-replicating cylindrical organelle, found in pairs that is involved in the process of nuclear division.
Centromere
The region joining the two sister chromatids where it becomes attached to a microtubule during mitosis.
Chromosome
A strand of DNA that carries the genetic information.
Sister chromatids
Two identical strands of DNA joined by a common centromere.
Supercoiling
The condensing of chromosomes as they become repeatedly coiled to make them much shorter, wider structures during prophase.
Microtubules
Hollow protein tubes seen during the mitosis of animal cells.
Spindle fibres
Network of microtubules that collectively form a mitotic spindle in mitosis.
Prophase
First stage of mitosis during which the chromosomes become visible as paired chromatids and the nuclear envelope disappears.
Metaphase
Stage in mitosis in which chromosomes become arranged at the equatorial plate.
Equatorial plate
Also, called the metaphase plate, the figure formed by the chromosomes in the centre of the spindle during mitosis.
Anaphase
Stage in mitosis in which sister chromatids are separated, pulled to opposite poles of a cell.
Telophase
The final stage of mitosis in which the separated chromosomes reach the op
Cytokinesis
The division of the cytoplasm and the plasma membrane, following the division of the nucleus resulting in two cells in mitosis.
Cell plate
A membrane that forms midway between dividing plant cells during cytokinesis and later becomes the cell wall.
Cyclins
A family of closely related proteins that regulate the cell cycle in eukaryotic cells.
Serendipity
Discovery by fortunate accident.
Oncogenes
A gene that causes normal cells to change into cancerous tumour cells.
Mutagens
Chemical agents that increase the rate of genetic mutation.
Tumours
An abnormal growth of tissue that develop at any stage of life in any part of the body.
Cancer
A malignant tumour and is named after the part of the body where the primary tumour first develops.
Primary tumour
Original histological site of cancerous growth of cells.
Secondary tumour
A colony of cancerous cells formed by the spread of cells from a primary tumour [metastasis].
Metastasis
The movement of cells from a primary tumour to set up secondary tumours in other parts of the body.
Mitotic index
The ratio between the number of cells in mitosis to the total number of cells.
