History of cell division
Hugo von Mohl, a German botanist, made the first observation of a cell division under a microscope in 1835 while studying the green alga Cladophora glomerata.
Kurt Michel initially captured cell division on film in 1943 while using a phase-contrast microscope.
Define Cell division
The procedure cells go through to divide is called cell division. Depending on the kind of organism dividing, there are various types of cell division. Over time, organisms have developed to have various, sophisticated ways of cell division. The majority of prokaryotes, or bacteria, divide their cells via binary fission.
Mitosis is the division process used by all eukaryotes. Meiosis is a particular kind of cell division that sexually reproducing eukaryotes utilize to minimize the amount of genetic material in each cell. This is essential for sexual reproduction because, without it, the offspring would have too much DNA, which can be problematic. Each parent must provide only half of the necessary genetic material.
What are the types of cell division?
Prokaryotic cell division:
Binary fission is a type of cell division used by prokaryotes to reproduce. Prokaryotes are straightforward organisms with a single membrane and no internal division. A prokaryote simply splits in two after replicating its DNA when it divides. The procedure is slightly more difficult since DNA must first be unraveled by unique proteins. Prokaryotes often have rings of DNA, but as the cell uses it, the DNA can become highly twisted. Stretching the DNA is necessary for effective DNA replication. Additionally, it makes it possible to separate the two new DNA rings after they are formed. The prokaryote cell’s two DNA strands divide into two distinct sides.
The braided line is the DNA. Other parts are identified by labels. Plasmids are tiny rings of DNA that are also replicated during binary fission and can be ingested from dead cells that disintegrate in the environment. Then, these plasmids can be repeated. A plasmid will spread more widely in a population if it is useful. This is one of the reasons why bacteria develop antibiotic resistance. The ribosomes are little protein building blocks that aid in the synthesis of proteins. For each cell to have enough to operate, they are also reproduced.
Binary fission:
Single-celled creatures like bacteria use binary fission to reproduce.
Eukaryotic cell division
Eukaryotic cell division is more difficult in eukaryotic creatures due to the presence of DNA on chromosomes and organelles that are membrane-bound. Before dividing, eukaryotes must reproduce their organelles, DNA, and cell structures. Scientists believe that eukaryotes were created by prokaryotes living inside of other prokaryotes since many of the organelles divide through a method that is virtually binary fission.
Meiosis
Usually, genetic information must be reduced before conception in sexually reproducing animals. In most species, having too many copies of the genetic code is generally damaging, while some plants can survive with too many copies. A human’s physique can change negatively if they have even one additional copy of a particular chromosome. Sexually reproducing creatures go through a process of cell division called meiosis to combat this. The DNA and organelles are duplicated just as they were before mitosis. Meiosis involves two distinct cell divisions that take place back-to-back. Homologous chromosomes are separated during the first meiosis, or meiosis I.
The two alleles of each gene an organism possesses are represented by the homologous chromosomes that are present in a cell. The daughter cells produced as a result of this recombination and separation have only one allele for each gene and no homologous pairs of chromosomes. Similar to mitosis, the second division, known as meiosis II, divided the two copies of DNA. In one cell, meiosis produces four cells, half the usual number, each containing one copy of the genome.
Usually, these cells are packaged by organisms into gametes, which can travel the environment in search of additional gametes. When the proper kind of gametes gets together, one will fertilize the other, creating a zygote. A single cell called the zygote will go through mitosis to divide into the millions of cells that make up an enormous organism. As a result, most eukaryotes go through both mitosis and meiosis at various points throughout their life cycle.
Mitosis
The eukaryote can start the process of mitosis once the DNA and organelles are replicated during the interphase of the cell cycle. When the chromosomes condense during prophase, the process starts. Chromosomes would not condense if mitosis continued, causing the DNA to twist and break. Numerous proteins that are found in eukaryotic cells help fold the DNA into intricate structures. The chromosomes are arranged in a straight line in the center of the cell as mitosis progresses to metaphase.
As mitosis progresses, a chromosome’s two halves, known as sister chromatids because they are duplicate copies of one another, are divided into two halves of the cell. The cell divides into two new daughter cells after the conclusion of mitosis by a different process known as cytokinesis. All eukaryotic species divide their cells via mitosis. However, mitosis is solely a method of reproduction used by single-celled organisms. The majority of multicellular organisms reproduce sexually, fusing their DNA with that of other living things. Organisms require a different strategy for cell division in these circumstances. Meiosis, which creates cells with half the genetic information of a typical cell, allows two cells from different animals of the same species to join. Mitosis produces identical cells.
Difference between prokaryotic and eukaryotic cell division
| Prokaryotic cell divisions | Eukaryotic cell divisions | |
| Definition | The process in which cells divide into two by binary fission | The process in which cells divide into two by mitosis & meiosis |
| Mechanism | It occurs through binary fission | It occurs through Mitosis, meiosis |
| Stages | The stages of division of cells are DNA replication and segregation | The stages of division of cells are nuclear division and cytokinesis |
| DNA replication | Replication occurs inside the cytoplasm | Replication occurs inside the nucleus |
| Complexity | Cell division is a relatively simple process | Cell division is relatively complex in eukaryotes |
| Type of Reproduction | It is a type of asexual reproduction | It contains vegetative and sexual reproduction |
Reference:
https://askabiologist.asu.edu/cell-division
https://byjus.com/biology/cell-division/
Cell Division
https://bio.libretexts.org/Bookshelves/Human_Biology/Book
