What is amphitelic attachment?
(A) Amphitelic attachments are defined by the attachment of the two sister kinetochores to microtubules from opposite spindle poles. This type of attachment is necessary for accurate chromosome segregation.
What is mono orientation?
Hence, sister kinetochores are attached in a monopolar fashion-this is called mono-orientation; however, in meiosis II, sister kinetochores are attached in a bipolar manner, they are bi-oriented (Petronczki et al, 2003; Duro & Marston, 2015) .
What is merotelic attachment?
Merotelic kinetochore attachment is an error that occurs when a single kinetochore is attached to microtubules emanating from both spindle poles. Merotelically attached kinetochores are frequently observed in the early stages of mitosis but most are corrected [1,2].
What is the metaphase checkpoint?
During metaphase, the kinetochore microtubules pull the sister chromatids back and forth until they align along the equator of the cell, called the equatorial plane. There is an important checkpoint in the middle of mitosis, called the metaphase checkpoint, during which the cell ensures that it is ready to divide.
What is mono orientation of sister chromatids?
This type of segregation is called reductional segregation. To achieve this, sister kinetochores must always be captured by microtubules emanating from the same poles, which is called mono-orientation of sister kinetochores.
What does G2 checkpoint do?
The G2 checkpoint prevents cells from entering mitosis when DNA is damaged, providing an opportunity for repair and stopping the proliferation of damaged cells. Because the G2 checkpoint helps to maintain genomic stability, it is an important focus in understanding the molecular causes of cancer.
What does G2 checkpoint check for?
The G2 checkpoint ensures all of the chromosomes have been replicated and that the replicated DNA is not damaged before cell enters mitosis. The M checkpoint determines whether all the sister chromatids are correctly attached to the spindle microtubules before the cell enters the irreversible anaphase stage.
Which of the following event occur in prometaphase?
Which of the following events occurs during prometaphase of mitosis? The nuclear envelope fragments. In animal cell mitosis, the cleavage furrow forms during which stage of the cell cycle?
What are the two features of prometaphase?
At prometaphase (late prophase) the chromosomes condense inside the nuclear envelope and asters of fibers appear on the outside of the chromosomes. When the nuclear envelope has disappeared, a spindle forms in prometaphase.
What is meant by centrosome cycle?
The centrosome cycle consists of four phases that are synchronized to the cell cycle. These include: centrosome duplication during the G1 phase and S Phase, centrosome maturation in the G2 phase, centrosome separation in the mitotic phase, and centrosome disorientation in the late mitotic phase—G1 phase.