Question

3. What is the role of the spindle fibers during mitosis? (1 point)

Answer 1

• Spindle fibers are responsible for segregating the chromosomes.

• Plant cells comprise a cell plate whereas animal cells have cleavage furrow.

Further Explanation:

Spindle fibers are basically protein structures which are made during early mitosis or the cellular division. It comprises of microtubules which arise from the centrioles. The spindle fibers supply a framework as well as means of attachment which keeps the chromosomes aligned, organized, as well as assorted during the whole cycle of mitosis. The chromosomes align themselves on the equatorial plate, during the second stage of mitosis called metaphase.  

Once the chromosomes are onto this plate, the adhesions found between the two groups of chromosomes dissolve and this action permits the spindle fibers which attach the chromosomes onto the centrioles at each terminal of the dividing cell in order to pull the 2 groups of the chromosomes apart. As anaphase begins, these spindle fibers pull each group towards the opposite side of the dividing cell.  

There are 2 methods of spindle shortening which aid in moving the chromosome:  

1. In one, the spindle fibers connect to the chromosomal kinetochores and begin to break down rapidly and depolymerize that shortens the microtubules and also moves the chromosomes near to the pole.  

2. Second mechanism is when the motor proteins found at the spindle poles pull the chromosomes near. At this stage phase, each group of chromosome separates to the terminals of the dividing cell and the spindle fibers also depolymerize. The cell them segregates into the 2 daughter cells.

Cell plate refers to the structure which occurs in the cells of the land plants when they are undergoing a cellular division. These cells, unlike animal cells, comprises of a cell wall which is made up of stiff sugars and are also surrounded by a cellular membrane. Cytokinesis found in the terrestrial plants takes place by the formation of the cellular plate. This process entails the delivery of the endosomal vesicles and Golgi-derived vesicles carrying a cell membrane as well as cell wall elements to the plane of the cellular division.  

Cleavage furrow, in animal cells, refers to the indentation of the surface of the cell which starts the progression of the cleavage by which certain algal cells as well as animal cells undergo cytokinesis. The positioning of the cell plate is decided by the microtubules, however, the position of the cleavage furrow is decided by the microfilaments. The cellular plate is observed to be in the middle and grows in centrifugal fashion by the deposition of the vesicles, but, a cleavage furrow is seen from the cell membrane and it grows in the centripetal fashion.

Learn more:

1.Learn more about  cell brainly.com/question/8900186

2. Learn more about  cell cycle brainly.com/question/1600165

3. Learn more about  cell division brainly.com/question/10767798

Answer Details:

Grade: Middle or high school

Subject: Biology

Chapter: Cell growth & division

Keywords:

Cell division, cytokinesis, cell cycle, cell plate, mitosis, spindle fibers, cleavage furrow, chromosomes, centrioles, kinetochores, anaphase, metaphase, telophase, animal cell, and plant cell.

Answer 2

3. A. They help separate the chromosomes
Spindle fibers attach to chromosomes and pull them towards different poles of the cell during the final phases of mitosis. The result is two identical cells with the same chromosomes.

4. C. A cell plate
A cell plate is a structure found in plant cells on the top and bottom of the cell. It is a perforated wall made of cellulose and it allows for substances to move in and out of the cell, as the outer most layer of a plant cell, the cell wall, is impermeable.