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Mitosis is the dividing of one cell to make a clone of the orginal cell. This process allows new cells to replace damaged ones, allowing you to recover from injuries and also to grow.
During the process of mitosis, only the DNA from the original cell needs to be copied. THE STAGES OF MITOSIS: During interphase, which is the period in which a cell is preparing to duplicate itself, long strands of DNA are loosely coiled up together, called chromatin. Another way for the cell to begin mitosis is by duplicating a pair of protein cylinders called centosome. The DNA also duplicates itself. Phophase- The chromatin coils up on itself and becomes thick strands of chromosomes. There are now pairs of chromotids, which together looks like an 'X'. The chromosomes begin moving to opposite ends of the cell, leaving behind a trail of protein ropes called microtubules. Metaphase- The chromosomes get attached to the protein ropes. Motor proteins then attach to the protein ropes and move the chromosomes around. All the chromosomes are then alligned straight down the middle of the cell, getting ready for the next part of mitosis. Ananphase- The protein ropes begin pulling so hard that the 'X' shaped chromosomes are split and pulled to opposite ends on the cell. Telephase- Each of the new cell structures are rebuilt, first the nucleur membrane, then membrane, and chromosomes relax back into chromotin. A small crease is formed between the two new cells, which is called cleavage. A clean break then occurs, leaving two similar cells. Cytoinesis is the process in which the two nuclei pull away from each other, separating the two cells. Each cell now has 46 chromosomes. The clones of the orginal cells are called 'daughter cells'. |
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MUTATION: 'Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message by that gene. A mutagen is an agent of substances that can bring about a permanent alteration to the physical composition of a DNA gene such that the genetic message is changed.'
Some examples of mutation in humans are:
Progia- this causes accelerated aging. It's caused by a mutation in the LMNA gene, a protein that provides support to the cell nucleous.
Hypertrichosis- this is also called the 'werewolf syndrome'. It causes people to have lots of hair all over their bodies, including their faces. This occurs due to a problem of the 'crosstalk' between the epidermis and dermis as hair follicles form in 3 month- old fetuses.
Some examples of mutation in humans are:
Progia- this causes accelerated aging. It's caused by a mutation in the LMNA gene, a protein that provides support to the cell nucleous.
Hypertrichosis- this is also called the 'werewolf syndrome'. It causes people to have lots of hair all over their bodies, including their faces. This occurs due to a problem of the 'crosstalk' between the epidermis and dermis as hair follicles form in 3 month- old fetuses.