Chromosomes are not visible in the cell's nucleus—not even under a microscope—when the cell is not dividing. However, the DNA that makes up chromosomes becomes more tightly packed during cell division and is then visible under a microscope. DNA and histone proteins are packaged into structures called chromosomes .
The chromosome that we see during cell division is a very tightly packaged structure as Dhaval's answer points out. This incredibly tightly folded structure is dense enough to be seen with a microscope but is really too dense for the cell to read any of the information from it in an efficient manner.
One may also ask, what is it called when a cell is not dividing? Interphase is the period of the cell cycle during which the cell is not dividing. The majority of cells are in interphase most of the time. Mitosis is the division of genetic material, during which the cell nucleus breaks down and two new, fully functional, nuclei are formed.
Chromatin is the masses of fine fibers comprising the chromosomes in the nucleus of a eukaryotic cell in a nondividing state. During cell division (mitosis or meiosis) the chromatin fibers pull together into thick shortened bodies which are then called chromosomes.
Chromosomes can be viewed relatively easily under the microscope, but only just before, during, and immediately after cell division. When a cell divides, the nucleus and its chromosomes also divide.
Below is a list of answers to questions that have a similarity, or relationship to, the answers on "Why can chromosomes only be seen when a cell is dividing?". This list is displayed so that you can easily and quickly access the available answers, without having to search first.
The parts of a chromosome are the Centromere, the Kinetochores, the Telomeres and a pair of sister Chromatids. The chromatids are each divided into a "p" arm and a "q" arm. (The p arm is the shorter one). The centromere is the part that connects the two chromatids together in an X shape.
There are two main functions of centrioles that we will focus on. The main function of the centriole is to help with cell division in animal cells. The centrioles help in the formation of the spindle fibers that separate the chromosomes during cell division (mitosis). Cilia and flagella help the cell move.
During interphase (1), chromatin is in its least condensed state and appears loosely distributed throughout the nucleus. Chromatin condensation begins during prophase (2) and chromosomes become visible. Chromosomes remain condensed throughout the various stages of mitosis (2-5).
One chromosome of each homologous pair comes from the mother (called a maternal chromosome) and one comes from the father (paternal chromsosome). Homologous chromosomes are similiar but not identical. Each carries the same genes in the same order, but the alleles for each trait may not be the same.
Mitosis ends with 2 identical cells, each with 2N chromosomes and 2X DNA content. All eukaryotic cells replicate via mitosis, except germline cells that undergo meiosis (see below) to produce gametes (eggs and sperm).
centromeres. … that holds together the two chromatids (the daughter strands of a replicated chromosome). The centromere is the point of attachment of the kinetochore, a structure to which the microtubules of the mitotic spindle become anchored.
Terms in this set (7)Interphase. Cell performs normal functions, Cell growth (G1 and g2), Synthesizes new molecules and organelles. Prophase. Prometaphase. Metaphase. Anaphase. Telophase. Cytokinesis.
Meiosis is a process where a single cell divides twice to produce four cells containing half the original amount of genetic information. These cells are our sex cells – sperm in males, eggs in females.
During most of the cell cycle, interphase, the chromosomes are somewhat less condensed and are not visible as individual objects under the light microscope. However during cell division, mitosis, the chromosomes become highly condensed and are then visible as dark distinct bodies within the nuclei of cells.
Mitosis occurs in every cell of the body except in germ cells which are produced from meiotic cell division.
In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females.
a small, cylindrical cell organelle, seen near the nucleus in the cytoplasm of most eukaryotic cells, that divides in perpendicular fashion during mitosis, the new pair of centrioles moving ahead of the spindle to opposite poles of the cell as the cell divides: identical in internal structure to a basal body.
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