Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure. … However, the DNA that makes up chromosomes becomes more tightly packed during cell division and is then visible under a microscope.
Why do chromosomes become visible during mitosis?
At the beginning of the first mitotic stage, prophase, the thread-like doubled chromosomes contract and become visible. The two centrioles move to opposite sides of the nucleus. … During metaphase, the nuclear membrane disappears and the chromosomes become aligned half way between the centrioles.
Why do chromosomes become visible?
During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses. The chromatin coils and becomes increasingly compact, resulting in the formation of visible chromosomes.
Are chromosomes visible during mitosis?
Chromosomes, composed of protein and DNA, are distinct dense bodies found in the nucleus of cells. … However during cell division, mitosis, the chromosomes become highly condensed and are then visible as dark distinct bodies within the nuclei of cells.
During which phase of mitosis do the chromosomes become visible?
In prophase, each chromosome becomes condensed and more visible, and there is the breakdown of the nuclear membrane and appearance of spindle fibers. In the next phase, metaphase, the chromosomes line up along the metaphase plate.
What phase of mitosis are chromosomes not visible?
During interphase, individual chromosomes are not visible, and the chromatin appears diffuse and unorganized.