During mitosis, the chromosomes condense so that each chromosome is a distinct unit. Prior to mitosis, the cell copies its DNA so that it contains two copies of each chromosome. … Condensing the DNA into tightly packed chromosomes makes the process of chromosome alignment and separation during mitosis more efficient.
Why the DNA must coil up into chromosome structures before it divides?
They contain all the genetic information of the living organism. Before the cell divides the chromosomes in the original parent cell must first be doubled (replicated). This happens so that when the cell divides into two new cells, both will be identical to the parent cell.
Why does a cell coil up before dividing?
During most of the life of a cell, its DNA is spread out in the nucleus. This allows the cellular machinery access to it in order to translate it into proteins. But when a cell is about to divide it makes a copy of its entire DNA, and then the chromosomes condense and line up in a row.
Why does mitosis have to come before cytokinesis in the cell cycle?
Explain why mitosis has to come before cytokinesis in the cell cycle. The contents of the nucleus must be duplicated and the chromosomes must be correctly divided up before the actual cell can divide into two new cells.
Why is it necessary that the nuclear membrane disintegrates during mitosis?
Why do you think it is necessary to disintegrate the nuclear membrane during mitosis? The nuclear membrane must be temporarily removed so the chromosomes can be divided into the two cells.
What is the reason why cells divide?
Cells must divide repeatedly for an embryo to develop or for you to grow. Cells also divide in order to replace damaged or worn-out cells. Most cell division produces genetically identical cells, meaning they have the same DNA.
What is it called when chromosomes coil up?
Prophase: The chromosomes coil and shorten, and become visible. It becomes apparent that the chromosomes have duplicated. Pairs of identical chromosomes remain attached to each other at the centromere and each chromosome is called a chromatid. Metaphase: Chromosomes line up along the center of the cell.
What happens before a cell divides?
Before a cell divides, the strands of DNA in the nucleus must be copied, checked for errors and then packaged into neat finger-like structures. The cell division stages encompass a complicated process that involves many changes inside the cell.
Does mitosis occur before cytokinesis?
At the end of interphase comes the mitotic phase, which is made up of mitosis and cytokinesis and leads to the formation of two daughter cells. Mitosis precedes cytokinesis, though the two processes typically overlap somewhat.
What stage of mitosis occurs immediately before cytokinesis?
Cytokinesis is initiated in prophase when a cytoskeleton of actin filaments and microtubules forms around the cell. This band is known as the preprophase band, and will later determine the positioning of the cell plate.
What is the purpose of the spindle fibers during mitosis?
Spindle fibers form a protein structure that divides the genetic material in a cell. The spindle is necessary to equally divide the chromosomes in a parental cell into two daughter cells during both types of nuclear division: mitosis and meiosis.
During which phase does the nuclear membrane reappear?
During telophase, chromosomes arrive at opposite poles and unwind into thin strands of DNA, the spindle fibers disappear, and the nuclear membrane reappears.
During which stage of mitosis do the chromosomes coil and condense?
Explanation: Prophase is the first stage of mitosis, during which the cell begins to position itself in order to separate the chromatids and divide. During prophase, the nuclear envelope and nucleolus are dissolved and the chromosomes condense.
Why is it important that mitosis occurs before cytokinesis quizlet?
Explain why mitosis has to come before cytokinesis in the cell cycle. Mitosis has to come before because cytokinesis because the chromosomes need to be separated. mitosis to make new cells to replace the damaged cells.