Algae, Tree, Herbs, Bush, Shrub, Grasses, Vines, Fern, Moss, Spermatophyta, Bryophyta, Fern Ally, Flower, Photosynthesis, Eukaryote, Prokaryote, carbohydrate, vitamins, amino acids, botany, lipids, proteins, cell, cell wall, biotechnology, metabolities, enzymes, agriculture, horticulture, agronomy, bryology, plaleobotany, phytochemistry, enthnobotany, anatomy, ecology, plant breeding, ecology, genetics, chlorophyll, chloroplast, gymnosperms, sporophytes, spores, seed, pollination, pollen, agriculture, horticulture, taxanomy, fungi, molecular biology, biochemistry, bioinfomatics, microbiology, fertilizers, insecticides, pesticides, herbicides, plant growth regulators, medicinal plants, herbal medicines, chemistry, cytogenetics, bryology, ethnobotany, plant pathology, methodolgy, research institutes, scientific journals, companies, farmer, scientists, plant nutrition
Select Language:
 
 
 
 
Main Menu
Please click the main subject to get the list of sub-categories
 
Services offered
 
 
 
 
  Section: Genetics » Physical Basis of Heredity » Cell Division (Mitosis and Meiosis)
 
 
Please share with your friends:  
 
 

Mitosis

 
     
 
Content
Physical Basis of Heredity 2.  Cell Division (Mitosis and Meiosis)
Mitosis
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
Meiosis 
Significance of meiosis
Reproductive cycles
Stages of meiosis
Synaptonemal complex
Recombination nodules
Comparison of meiosis and mitosis


The development of an individual from zygote to adult stage takes place through mitotic cell divisions. Although growth also takes place through increase in cell size, but when cell size increases, surface area of cell does not increase in the same proportion as the cell volume. Therefore, cell division helps in growth also by way of increasing surface area of the cells. Therefore, mitosis is a necessity for maintenance and perpetuation of life.

One of the basic requirements of cell division meant for growth should be that it should give rise to two daughter cells, which should resemble each other and also the parent cell qualitatively and quantitatively. The basic outline of such a cell division is the same in all kinds of living forms. It consists of following stages forming a cell cycle. It should be realized that mitotic division is a continuous process and its division into stages is done only for convenience of description. Cell cycle (interphase and mitosis)

In continuously dividing cells, an individual cell passes through four phases, listed in Table 7.1 and diagrammatically shown in Figure 7.1.
 
Diagrammatic representation of cell cycle of mouse L cells doubling every 24 hours (redrawn from Lewin's Gene Expression-2).
Fig. 7.1. Diagrammatic representation of cell cycle of mouse L cells doubling every 24 hours (redrawn from Lewin's Gene Expression-2).

G1 is a resting phase; during S phase, DNA synthesis takes place and G2 phase is again a resting phase following DNA synthesis. These three phases viz. G1, S and G2 constitute interphase, while the main mitotic division takes place during M phase. Durations of different phases vary not only in different materials, but also in different tissues of the same organism. These may also vary in cells in culture using different culture media. The durations of different phases in three materials are given in Table 7.1. The mitotic phase consists of the following stages :

genteic botany Biocyclopedia.com
 
     
 
 
     




     
 
Copyrights 2012 © Biocyclopedia.com | Disclaimer