disease to increase yield Mitosis and Telomeres Telomere are caps at the ends

Disease to increase yield mitosis and telomeres

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disease to increase yield
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Mitosis and Telomeres - Telomere are caps at the ends of chromosomes - Scientists have determined that telomeres reduce in length each time a cell goes through the cell cycle and divides - Telomeres might have a role in cell aging and in the behaviour of cancer cells - Yeast cells that lack the enzyme telomerase undergo telomere shortening and eventually die - As human cells age, telomere length shortens - The length of chromosomes of a 70 year old human is much shorter than that of a child - Normal cells pass through the cell cycle only a finite number of times - Once a cell can no longer undergo mitosis, cell death occurs - Telomere length serves as a molecular “clock” for cellular aging
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Human Cell Mitosis - In the human body, cells generally undergo mitosis only 50 to 100 times during their lifespan - Cancer cells, however, never seem to lose their ability to divide, and their telomere length is also maintained - Telomerase is also not present in most normal cells - Telomerase is reactivated in human cancer cells - This allows cancer cells to maintain telomere length and, therefore, their ability to divide - Decreasing telomerase activity might slow cell division of cancer cells, though it has little impact on normal cells Summary: Applications of the Cell Cycle - Cloning is the process of forming identical offspring from a single cell or tissue - Cloning permits the production of offspring with characteristics identical to those of the parent - Some plants and animals naturally clone themselves (reproduce asexually) - Technologies have been developed to clone both plants and animals - Further development of cloning technology relies on increased understanding of cell processes such as mitosis
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17.3 Meiosis Meiosis - Meiosis is the type of cell division involved in the formation of sex cells, or gametes - In humans, this takes place in the testes and ovaries - Meiosis involves two stages of cell division that have some similarities to the phases in mitosis - In mitosis, the chromosome number of the daughter cells is the same as the parent cell - In meiosis, the chromosomes number of the daughter cell is half that of the parent cell - A human cell containing 46 chromosomes will undergo meiosis and produce gametes that have 23 chromosomes - Each gamete will contain both the same number and the same kind of chromosomes Haploid and Diploid - The number of chromosomes in a gamete is called haploid chromosome number, or n - The number of chromosomes in all other cells having a nucleus is twice the haploid number and is called the diploid number, or 2n - In humans, the haploid chromosome number is 23 and the diploid chromosome number is 46 Offspring Genetic Information - Offspring carry genetic information from each of the parents - This explains why offspring share some physical aspects of both parents - Although an offspring may look more like one parent than another, genetic information is received from each parent - For example, your father gives you a chromosome with genes that code for eye colour,
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