Mitosis
Cell division involves the distribution of identical genetic material, DNA, to two daughters cells. What is most remarkable is the fidelity with which the DNA is passed along, without dilution or error, from one generation to the next.
Core Concepts:
- All Organisms Consist of Cells and Arise from Preexisting Cells
- Mitosis is the process by which new cells are generated.
- Meiosis is the process by which gametes are generated for reproduction.
- The Cell Cycle Represents All Phases in the Life of a Cell
- DNA replication (S phase) must precede mitosis, so that all daughter cells receive the same complement of chromosomes as the parent cell.
- The gap phases separate mitosis from S phase. This is the time when molecular signals mediate the switch in cellular activity.
- Mitosis involves the separation of copied chromosomes into separate cells.
In order to better understand the concept of cell division and genetics, some basic definitions are in order:
- gene – basic unit of heredity; codes for a specific trait
- locus – the specific location of a gene on a chromosome (locus – plural loci)
- genome – the total hereditary endowment of DNA of a cell or organism
- somatic cell – all body cells except reproductive cells
- gamete – reproductive cells (i.e. sperm & eggs)
- chromosome – elongate cellular structure composed of DNA and protein – they are the vehicles which carry DNA in cells
- diploid (2n) – cellular condition where each chromosome type is represented by two homologous chromosomes
- haploid (n) – cellular condition where each chromosome type is represented by only one chromosome
- homologous chromosome – chromosome of the same size and shape which carry the same type of genes
- chromatid – one of two duplicated chromosomes connected at the centromere
- centromere – region of chromosome where microtubules attach during mitosis and meiosis
Terms to know about Mitosis and Meiosis.
Cell division and Mitosis Quiz.
Meiosis
Genetics
Gregor Mendel
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