Mitosis is the process by which a cell, which has previously replicated each of its chromosomes, separates the chromosomes in its cell nucleus into two identical sets of chromosomes, each set in its own new nucleus. It is a form of nuclear division. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles, and cell membrane into two cells containing roughly equal shares of these cellular components. Mitosis and cytokinesis together define the mitotic (M) phase of the cell cycle—the division of the mother cell into two daughter cells, genetically identical to each other and to their parent cell. This accounts for approximately 10% of the cell cycle.
Mitosis occurs only in eukaryotic cells and the process varies in different species. For example, animals undergo an “open“ mitosis, where the nuclear envelope breaks down before the chromosomes separate, while fungi such as Aspergillus nidulans and Saccharomyces cerevisiae (yeast) undergo a “closed“ mitosis, where chromosomes divide within an intact cell nucleus. Prokaryotic cells, which lack a nucleus, divide by a process called binary fission.
The process of mitosis is fast and highly complex. The sequence of events is divided into stages corresponding to the completion of one set of activities and the start of the next. These stages are prophase, prometaphase, metaphase, anaphase and telophase. During mitosis the pairs of chromatids condense and attach to fibers that pull the sister chromatids to opposite sides of the cell. The cell then divides in cytokinesis, to produce two daughter cells.
Because cytokinesis often occurs in conjunction with mitosis, “mitosis“ is often used interchangeably with “mitotic phase“. However, there are many cells where mitosis and cytokinesis occur separately, forming single cells with multiple nuclei. This occurs most notably among the fungi and slime molds, but is found in various groups. Even in animals, cytokinesis and mitosis may occur independently, for instance during certain stages of fruit fly embryonic development. Errors in mitosis can either kill a cell through apoptosis or cause mutations. Certain types of cancer can arise from such mutations.
Mitosis was discovered in frog, rabbit, and cat cornea cells in 1873 and described for the first time by the Polish histologist Wacław Mayzel in 1875. The term is derived from the Greek word mitos i.e. “warp thread“.
#alleles #chromosome #geneticCode #eukaryotic #genotype #eukaryotes #molecularBiology #Genetics101 #proteins #embryonicDevelopment #AspergillusNidulans #phenotype #GeneticExamQuestionsSolutions #mitosis #mitoticPhase #GeneticsLecture #genetics #DNA #genomes #genes #chromosomes #geneExpression #gene #RNA #fungi #GeneStructure
1 view
173
59
2 months ago 00:35:26 1
Ron Vale (UCSF, HHMI) 1: Molecular Motor Proteins
3 months ago 00:03:57 1
Erick the Architect - Instincts ft. WESTSIDE BOOGIE
1 year ago 02:00:00 1
SAMADHI Meditation Music! Supreme State of Consciousness
2 years ago 00:05:21 1
Taq polymerase
2 years ago 00:03:48 1
Aneuploid, Euploid, Polyploid, Tetraploid
2 years ago 00:06:24 1
When our cells are Tetraploid and Diploid during Mitosis?
2 years ago 00:02:36 1
Interphase
2 years ago 00:04:57 1
Cell cycle explained
2 years ago 00:13:39 1
Hardy-Weinberg problem and solution
2 years ago 00:13:40 1
Hardy-Weinberg equilibrium applied to population genetics problem
2 years ago 00:07:04 1
How to find a phenotypic ratio of a cross dihybrid with double homozygous recessive
2 years ago 00:04:51 1
ABO Blood types problem and solution
2 years ago 00:07:20 1
Ptosis - Dominant genetic disorder problem and solution
2 years ago 00:07:23 1
Mitosis problem solving example
2 years ago 00:04:49 1
Ploidy level problem
2 years ago 00:13:39 1
X chromosome mosaicism in women
2 years ago 00:08:58 1
Simple Mendelian genetics problem
2 years ago 00:07:22 1
Phenylketonuria (PKU) and law of probability
2 years ago 00:05:47 1
Dihybrid crossing - problem solution
3 years ago 00:25:13 1
What Students Need to Know about Chromosomal Abnormalities.
8 years ago 00:03:56 1
Two Minute Papers - Artistic Style Transfer For Videos
9 years ago 00:02:40 72
Two Minute Papers - Deep Learning Program Learns to Paint
9 years ago 00:01:47 1
Two Minute Papers - Deep Neural Network Learns Van Gogh’s Art