Search results
Results from the WOW.Com Content Network
Leland Harrison "Lee" Hartwell (born October 30, 1939) is an American former president and director of the Fred Hutchinson Cancer Research Center in Seattle, Washington.He shared the 2001 Nobel Prize in Physiology or Medicine with Paul Nurse and Tim Hunt, for their discoveries of protein molecules that control the division (duplication) of cells.
The eukaryotic cell cycle consists of four distinct phases: G 1 phase, S phase (synthesis), G 2 phase (collectively known as interphase) and M phase (mitosis and cytokinesis). M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's nucleus divides, and cytokinesis, in which the cell's cytoplasm and cell membrane divides forming two daughter cells.
The three laureates are cited "for their discoveries of key regulators of the cell cycle," while Hunt in particular is awarded for his discovery of cyclins, proteins that regulate the CDK function. He showed that cyclins are degraded periodically at each cell division, a mechanism proved to be of general importance for cell cycle control. [43]
The transposition of Ds in different cells is random, it may move in some but not others, which causes color mosaicism. The size of the colored spot on the seed is determined by stage of the seed development during dissociation. McClintock also found that the transposition of Ds is determined by the number of Ac copies in the cell. [54]
The longest appendix ever removed was 26 cm (10 in) long. [3] The appendix is usually located in the lower right quadrant of the abdomen, near the right hip bone. The base of the appendix is located 2 cm (0.79 in) beneath the ileocecal valve that separates the large intestine from the small
Steps of the cell cycle. The restriction point occurs between the G 1 and S phases of interphase.. The restriction point (R), also known as the Start or G 1 /S checkpoint, is a cell cycle checkpoint in the G 1 phase of the animal cell cycle at which the cell becomes "committed" to the cell cycle, and after which extracellular signals are no longer required to stimulate proliferation. [1]
Theodor Heinrich Boveri (12 October 1862 – 15 October 1915) was a German zoologist, comparative anatomist and co-founder of modern cytology. [1] He was notable for the first hypothesis regarding cellular processes that cause cancer, and for describing chromatin diminution in nematodes. [2]
Compared to the eukaryotic cell cycle, the prokaryotic cell cycle (known as binary fission) is relatively simple and quick: the chromosome replicates from the origin of replication, a new membrane is assembled, and the cell wall forms a septum which divides the cell into two.