How do spindle fibers shorten?
If this concept is correct, the spindle microtubules attached to the kinetochores of the sister chromatids
, shorten by depolymerization (removal) of protein subunits at their polar ends. This would shorten the microtubule and “pull” on it, tugging the chromosome half towards that pole.
How does spindle fibers lengthen and shorten?
Do spindle fibres shorten?
Do spindle fibers shorten in mitosis?
What phase to spindle fibers shorten?
What is the result of mitosis?
Mitosis results in two identical daughter cells, whereas meiosis results in four sex cells.
What do centrioles attach to?
Centrioles begin moving to opposite ends of the cell, and microtubules extend from the centrioles and begin to attach to the centromeres of chromosomes. Eventually, the microtubules extending from centrioles on opposite poles of the cell attach to every centromere and develop into spindle fibers.
What is the end result of mitosis?
Mitosis results in two identical daughter cells, whereas meiosis results in four sex cells.
How does muscle spindle work?
Functionally, muscle spindles are stretch detectors, i.e. they sense how much and how fast a muscle is lengthened or shortened [19]. Accordingly, when a muscle is stretched, this change in length is transmitted to the spindles and their intrafusal fibers which are subsequently similarly stretched.
Which is a factor that can stop normal cells from growing?
When cells are grown in a laboratory, which is a factor that can stop normal cells from dividing? obtaining enough food.
Why do cells divide?
Cells need to divide for your body to grow and for body tissue such as skin to continuously renew itself. When a cell divides, the outer membrane increasingly pinches inward until the new cells that are forming separate from each other. This process typically produces two new (daughter) cells from one (parent) cell.
What happens at the very end of mitosis?
Mitosis ends with telophase, or the stage at which the chromosomes reach the poles. The nuclear membrane then reforms, and the chromosomes begin to decondense into their interphase conformations. Telophase is followed by cytokinesis, or the division of the cytoplasm into two daughter cells.
How many stages are there in mitosis?
Today, mitosis is understood to involve five phases, based on the physical state of the chromosomes and spindle. These phases are prophase, prometaphase, metaphase, anaphase, and telophase.
How many daughter cells are produced by each of these processes?
The overall process of meiosis produces four daughter cells from one single parent cell. Each daughter cell is haploid, because it has half the number of chromosomes as the original parent cell.
Where is DNA found inside a cell?
Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA). Mitochondria are structures within cells that convert the energy from food into a form that cells can use.
How does a cell prepare to divide?
A cell spends most of its time in what is called interphase, and during this time it grows, replicates its chromosomes, and prepares for cell division. The cell then leaves interphase, undergoes mitosis, and completes its division.
What is the process of mitosis in a tissue culture?
Cell division, or mitosis (meiosis in germ cells), consists of a series of dynamic events that involve the coordinated interactions of many cellular components. During mitosis, the replicated DNA condenses into chromosomes, which then become attached to a complex structure known as the ‘mitotic spindle.
Where is the motor end plate found?
Neuromuscular junctions, also called motor end plates, are specialised chemical synapses formed at the sites where the terminal branches of the axon of a motor neuron contact a target muscle cell.
How does the stretch shortening cycle work?
The stretch-shortening cycle (SSC) refers to the muscle action when active muscle lengthening is immediately followed by active muscle shortening. This combination of eccentric and concentric contractions is one the most common type of muscle action during locomotion.
Which human cells divide the fastest?
Epithelial and and blood cells are the two of the main types of cells that need to be constantly replaced in developed organisms. As far as I know cells lining the gut epithelium are fastest to divide.
What are the fastest growing cells in the human body?
Hair follicles, skin, and the cells that line the gastrointestinal tract are some of the fastest growing cells in the human body, and therefore are most sensitive to the effects of chemotherapy.