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10 1-2 MitosisMeios
Yr 10 Ch 1-2 Mitosis
Term | Definition |
---|---|
Replication | the process of copying DNA |
Chromosome | is made of a single DNA piece, which has been supercoiled and organized around various proteins. It's the dense form of DNA and seen just prior to cell replication. |
Chromatid | is half of a replicated chromosome. When the chromosome replicates, it results in the well known X shape. The X contains two copies of the same DNA. Two sister chromatids are attached at the centromere to make up a replicated chromosome. |
Mitosis | produces two daughter cells that are exact replicas of the original cell - cloning (23 pairs of chromosomes in each new cell). This is done for growth and repair. Diploid or two. Makes It Two M-i-t (makes twins) |
Meiosis | produces gametes (egg and sperm cells) each has only 23 single chromosomes. Haploid or Half. When a sperm and egg combine the result is a new cell with 23 pairs of chromosomes. |
Interphase | replication of the DNA to become double stranded |
Prophase | double stranded chromosomes become visible (condense) |
Metaphase | chromosomes line up at the middle of the cell |
Anaphase | the chromosomes split and move to opposite ends of the cell |
Telephase | the two new nuclei form - each with the diploid number of chromosomes eg in humans 23 pairs |
Cytokinesis | membrane forms that splits the two nuclei and the cell pinches into two new fully functional daughter cells - clones of the original. |
Autosomes | 22 pairs of human homologous chromosomes (are not sex determining) - homologous means ideally they are exact replicas. |
Sex chromosomes | Pair 23 has either 2 X's in the case of females and an X and a Y for a male |
Diploid | 23 pairs of chromosomes |
Haploid | 23 single chromosomes |
Asexual reproduction | cloning - no mixing of genetic material as there is only one parent. Produces off spring that are ideally suited to the current environmental conditions. |
Sexual reproduction | genetic material is supplied by both parents and the offspring take on some characteristics of both parents - more variable and responsive to changes in the environment. |