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.
Cancer
general term for more than 100 diseases that are characterized by uncontrolled, abnormal growth of cells.
Cell plate
a membrane that forms midway between dividing plant cells during cytokinesis and later becomes the cell wall.
Centrioles
a self-replicating cylindrical organelle that is involved in the process of nuclear division.
Centromere
the region joining the two sister chromatids where it becomes attached to the spindle fibres.
Chromosomes
linear strand of DNA bonded to proteins in the nucleus of eukaryotic cells that carries the genetic information.
Cyclins
a family of closely related proteins that regulate the cell cycle in eukaryotic cells.
Cytokinesis
the division of the cytoplasm and the plasma membrane, following the division of the nucleus, resulting in two cells in mitosis.
Equatorial plate
the figure formed by the chromosomes in the centre of the spindle during mitosis.
Metaphase
stage in mitosis in which chromosomes become arranged at the equatorial plate.
Metastasis
characteristic of malignant tumours of transferring the disease from one organ to another not directly connected with it.
Microtubule fibres
hollow protein tubes seen during the mitosis of animal cells.
Mitosis
the process where a single cell divides into two identical cells, each containing the same number of chromosomes and genetic content as that of the original cell.
Mitotic index
the ratio between the number of cells in mitosis to the total number of cells.
Mutagens
chemical agents that increase the rate of genetic mutation.
Oncogenes
a gene that causes normal cells to change into cancerous tumour cells.
Prophase
first stage of mitosis during which the chromosomes become visible as paired chromatids and the nuclear envelope disappears.
Sister chromatids
two identical strands of DNA joined by a common centromere.
Spindle fibres
network of filaments that collectively form a mitotic spindle in mitosis. They are involved in moving the chromosomes during nuclear division.
Supercoiling
twisting in the opposite direction to the turns of the double helix during the first stage of mitosis.
Telophase
the final stage of mitosis in which the separated chromosomes reach the opposite poles of the dividing cell and the nuclei of the daughter cells form around them.
Tumours
abnormal proliferation of cells, either benign or malignant.
