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Mutation, Mutation II aneuploidy and polyploidy, Mutation I consists of…
Mutation
Gene Mutation
Genetic mutations may occur during cell division when cells divide and replicate. There are two types of cell division:
Mitosis: The process of making new cells for your body. During mitosis, your genes instruct your cells to split into two by making a copy of your chromosomes.
Meiosis: The process of making egg and sperm cells for the next generation. During meiosis, chromosomes copy themselves with half the amount of chromosomes as the original (from 46 to 23). That’s how you’re able to get your genetic material equally from each parent.
A genetic mutation is a change in a sequence of the DNA. The DNA sequence gives cells the information they need to perform their functions. Some mutations can lead to genetic disorders or illnesses.
Cause
Error in DNA replication: When a cell divides, a copy of DNA is made. However, not every copy of DNA is perfect and a small difference occur. This causes mutation. The more cell divisions there are, the higher chance of errors happening in DNA replication.
Fail in repairation: When a DNA is damaged, a cell would try to repair it or put the strand back together. However, it is possible for the cell to mistakenly substitute the genetic letter. This leads to mutation.
External cause: Heat, radiation or specific chemicals known as mutagens (such as UV light) can damage or cause changes to the covalent bonds between nitrogenous bases in DNA.
Cell division
Genetic mutations occur during cell division. When your cells divide, they hand-write your body’s instruction manual by copying the original document word for word. There’s a lot of room for error during cell division because your cells might substitute (replace), delete (remove) or insert (add) letters while they’re copying. If you have an error (genetic mutation), your genetic instruction manual for your cells may not be readable by the cells, or may have missing parts or unnecessary parts added. All of this can mean that your cells can’t function as they normally should.
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We can inherit germline genetic mutations. There are several patterns that genetic mutations can pass from the parent to a child (hereditary) :
Autosomal dominant.
Only one parent needs to pass the genetic mutation onto their child for their child to inherit the mutation.
Example of it is marfan syndrome
Autosomal recessive.
Both parents need to pass the same genetic mutation onto their child for their child to inherit the mutation.
Example of this is Sickle cell disease
X-linked.
Babies assigned male or female have an X chromosome. Mutations on the X chromosome can pass in a dominant or recessive pattern, but not every pattern is clear on how the child acquired the mutation from their parents.
Example of it is Thrombocytopenia
Y-linked.
Only babies assigned male at birth have a Y chromosome and can inherit this type. Only one mutation on the Y chromosome needs to pass to the child to inherit the mutation.
Example of it is Webbed feet
Codominant.
Each gene has two parts (one from the egg and one from the sperm). They usually work together to create a single trait. But sometimes, they each work separately to produce variations of the trait.
Example of it is Alpha-1 antitrypsin deficiency
Chromosome Mutation
Definition: Chromosome structure mutations are alterations that affect whole chromosomes and whole genes rather than just individual nucleotides. These mutations result from errors in cell division that cause a section of a chromosome to break off, be duplicated or move onto another chromosome.
Short definition: a chromosome mutation affects the chromosome and genes as a whole. This mutation creates irregular chromosome patterns which can end up in the wrong places or go through the wrong process.
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Cause
A chromosomal mutation happens because of a change in chromosome structures, chromosomal rearrangement, or other chromosomal abnormalities such as a change in chromosome number or missing chromosome.
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Lagging in division phase: If some portions of chromosomes "lag" in anaphase, they could be lost during the nuclei reorganization phase (Telophase)
External cause: Heat, radiation or specific chemicals known as mutagens (such as UV light) can damage or cause changes to the covalent bonds between nitrogenous bases in DNA.
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Mutation I consists of inversion, deletion, duplication, and translocation
