I) At some points during a cell\'s life, its genetic material is \"unraveled\" a
ID: 87106 • Letter: I
Question
I) At some points during a cell's life, its genetic material is "unraveled" and diffuse (see Cell A below). At other points during times during a cell's life, its genetic material becomes compacted so that you can see individual chromosomes (see Cell B below). a) Which of the above cells shows what the genetic material looks like during interphase? Cell A OR Cell B b) In your own words, briefly describe what cells are doing during interphase. In other words, what's the purpose of interphase? c) In your own words, briefly describe what cells are doing during mitotic phase. In other words, what's the purpose of mitotic phase? d) Consider the time period that starts when a cell is "born" and ends when the cell divides.Explanation / Answer
(a) Cell A has the genetic material looking like interphase.
(b) In the interphase, the cells grow and make structural proteins that repair damaged parts, transport nutrients to where they are needed, eliminate wastes, and prepare themselves for mitosis by building proteins. The genetic material during an interphase is termed as a chromatin. This phase is the time interval between nuclear divisions. During this phase, the cell increases in mass that is it doubles the cytoplasmic components and duplicates its chromosomes.
This phase comes between mitosis in the cell cycle which is the period of normal cell growth. Those cells that do not need to replicate will spend their time in this stage. And, if a cell does need to divide, it will copy its entire DNA in this period. This way, the cell has two complete copies of its DNA before it begins the process of mitosis.
(c) Mitosis is a four-stage process that creates two identical daughter cells from one original cell. It comprises 4 stages:
(1) Prophase - this is the first and longest stage of mitosis where, the chromosomes become visible and the centrioles separate and move to opposite poles of the cell.
(2) Metaphase - this is the second stage of mitosis where, the chromosomes line up across the center of the cell and become connected to the spindle fiber at their centromere.
(3) Anaphase - this is the third stage of mitosis where, the sister chromatids separate into individual chromosomes and are pulled apart.
(4) Telophase - this is the fourth or last stage of mitosis where, the chromosomes gather at opposite ends of the cell and lose their distinct rod-like shapes. Two new nuclear membranes then form around each of the two regions of DNA and the spindle fibers disappear.
This stage is followed by cytokinesis where, the two complete copies of the DNA are formed in two different regions of one cell. The cell membrane pinches and divides the cytoplasm in half which results in two individual cells those are identical to the original cell. Each of the two cells has a complete copy of the DNA and contains all of the organelles that the original cell had.