Why does mitosis occur within a cell

Chromosome Theory and the Castle and Morgan Debate. Discovery and Types of Genetic Linkage. Genetics and Statistical Analysis. Thomas Hunt Morgan and Sex Linkage. Developing the Chromosome Theory. Genetic Recombination. Gregor Mendel and the Principles of Inheritance. Mitosis, Meiosis, and Inheritance. Multifactorial Inheritance and Genetic Disease. Non-nuclear Genes and Their Inheritance. Polygenic Inheritance and Gene Mapping. Sex Chromosomes and Sex Determination. Sex Determination in Honeybees.

Test Crosses. Biological Complexity and Integrative Levels of Organization. Genetics of Dog Breeding.

Human Evolutionary Tree. Mendelian Ratios and Lethal Genes. Environmental Influences on Gene Expression. Epistasis: Gene Interaction and Phenotype Effects. Genetic Dominance: Genotype-Phenotype Relationships. Phenotype Variability: Penetrance and Expressivity.

Citation: Miko, I. Nature Education 1 1 Although mitosis and meiosis both involve cell division, they transmit genetic material in very different ways. What happens when either of these processes goes awry? Aa Aa Aa. Gene Transmission in Mitosis. Figure 1. Gene Transmission in Meiosis. Figure 2: Examples of polytene chromosomes.

Pairing of homologous chromatids results in hundreds to thousands of individual chromatid copies aligned tightly in parallel to produce giant, "polytene" chromosomes. High-pressure treatment of polytene chromosomes improves structural resolution. Nature Methods 4, All rights reserved. Aberrations That Alter Chromosome Number. Figure 3: Nondisjunction results in daughter cells with unusual chromosome numbers. Nondisjunction, in which chromosomes fail to separate equally, can occur in meiosis I first row , meiosis II second row , and mitosis third row.

These unequal separations can produce daughter cells with unexpected chromosome numbers, called aneuploids. When a haploid gamete does not receive a chromosome during meiosis as a result of nondisjunction, it combines with another gamete to form a monosomic zygote. When a gamete receives a complete homologous chromosome pair as a result of nondisjunction, it combines with another gamete to form a trisomic zygote.

Genetics: A Conceptual Approach , 2nd ed. Figure 4: Jimsonweed seed pod shapes. Trisomy in any of Jimsonweed's 12 chromosomes will cause seed pods to deviate from a wild-type, spherical shape. References and Recommended Reading Belling, J. Genetics: A Conceptual Approach W. Freeman, New York, Article History Close.

Share Cancel. Revoke Cancel. Keywords Keywords for this Article. Save Cancel. Flag Inappropriate The Content is: Objectionable. Flag Content Cancel. Email your Friend. Submit Cancel. This content is currently under construction. See the graphic below. Prophase : The chromosomes coil and shorten, and become visible. It becomes apparent that the chromosomes have duplicated. Pairs of identical chromosomes remain attached to each other at the centromere and each chromosome is called a chromatid.

Metaphase : Chromosomes line up along the center of the cell. Why does mitosis take place? Biology The Eukaryotic Cell Mitosis. Linica Uday. May 25, Explanation: Mitosis ensures that all the cells will have same number of chromosomes. Related questions Why is mitosis necessary for living organisms? How is metaphase distinguished? How do cytokinesis and telophase differ?

How do chromosomes divide during anaphase?