Ploidy Back to Top Haploid and diploid are terms referring to the number of sets of chromosomes in a cell.
Binary fission, Mitosis, and Meiosis Whereas binary fission takes place in prokaryotic cells of simple single-celled organisms such as bacteria. Mitosis and meiosis take place in eukaryotic cells and are more advanced. Although there are differences between prokaryotes and eukaryotes, there are a number of features that are common during their processes of cell division.
Genetic material nucleoid in these cells is arranged in a single circular chromosome of the DNA. In a similar fashion to eukaryotes, the genetic material of these cells is duplicated before division.
As the prokaryote elongates, the two chromosomes attached to the plasma membrane also move apart, and once the two copies have separated the original and replicate chromosomesthe cell divides, a process referred to as cytokinesis.
Except in a case of mutation, the two resultant cells are identical. Eukaryotes Eukaryotic cells are more complicated given that they contain more organelles as compared to the prokaryotic cells. The cell cycle, which is composed of four main phases, is responsible for planning and the development of these cells.
This cycle is also composed of all the steps required for the reproduction of a eukaryotic cell. The four phases of a cell cycle include: G1- during this phase, a cell prepares for the synthesis stage by making sure that all material required for DNA synthesis are present.
S phase- during the phase, DNA is copied so that the daughter cells have a complete set of chromosomes at the end of the cycle. M phase- it is during this phase mitosis that the cell separates into two new cells.
The first three stages make up the interphase stage, where the cell spends about 90 percent of the cycle. Mitosis This is the process through which identical daughter cells are formed through replication and the original replication of chromosomes. The daughter cells are identical to the parent cells in that, if the parent cell is diploid, then the daughter cell will be diploid as well.
During mitosis, the replicated chromosomes are positioned at the middle of the cytoplasm. They are segregated so that the daughter cells can get a copy of the original DNA. This is made possible by the presence of microtubules spindle fiberswhich pull the chromosomes into each of the cells.
These fibers arise from the centrioles, which are on either side of the cells, and may have even smaller microtubules referred to as aster. These are thought to serve as braces for the functioning of the fibers. Interphase During the interphase period, the cell replicates its DNA chromosomes as it prepares for the division.
Chromosomes at this stage are not easily visible since they are uncoiled. Prophase This is the first phase in mitosis. The nuclear envelope also starts to dissolve. The chromosomes also starts coiling and spindle fibers start forming as centrosomes divide and start migrating to either side of the cell.
During the pro-metaphase the nuclear envelope breaks down and the kinetochore microtubules appear to interact with polar microtubules of the spindle fibers. This brings about the movement of the chromosomes.Jan 21, · Cell division is the process by which biological cells multiply.
There are three major types of cell division: Mitosis - used by Eukaryotic organisms to grow or reproduce asexually;Reviews: Meiosis is a special type of cell division that takes place only in cells involved in sexual reproduction.
In higher organisms like humans, these are immature sperm cells in . Each of these methods of cell division has special characteristics. One of the key differences in mitosis is a single cell divides into two cells that are replicas of each other and have the same number of chromosomes.
This type of cell division is good for basic growth, repair, and maintenance. Meiosis produces 4 haploid cells. Mitosis produces 2 diploid cells. The old name for meiosis was reduction/ division. Meiosis I reduces the ploidy level from 2n to n (reduction) while Meiosis II divides the remaining set of chromosomes in a mitosis-like process (division).
Cell division: mitosis and meiosis Learning Objectives Describe the chromosomal makeup of a cell using the terms chromosome, sister chromatid, homologous chromosome, diploid, haploid, and tetrad.
Start studying Chapter 8, Cellular Reproduction. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Mitosis is the type of cell division responsible for: of an egg by a sperm using a special type of cell division called meiosis. Thus, sexually reproducing organisms use: Meiosis for reproduction Mitosis .