Section 13.3 Mutations - 4Schools

spouse may be carrying mutations that show up only in your offspring. 3. Mutations can accumulate throughout your life ... Section 13.3 Mutations Auth...

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Mutations

Mutations - Are inheritable changes in genetic information. Spelling errors in the DNA. - Mutations can also accumulate throughout your own individual life span -Can be harmful,beneficial or neither - Have two major types:

- Chromosomal mutations - Point mutations

Causes of Mutations - Include naturally-occuring errors - Can occur during replication

- Include chemical and physical agents in the environment, called mutagens - Chemicals - Radiation

Effects of Mutations - Can be harmful - Change protein structure or gene activity in a negative way - Sickle cell anemia

- Can be helpful - Change protein structure or gene activity in a positive way - Increase disease resistance - Create better physiological function

- Some mutations have no effect at all

Human Karyotype

This is a picture of a person’s chromosomes right after DNA replication and right before cell division. All the DNA is packaged into 46 individual units. 23 you get from mom and 23 you get from dad. Mutations can involve entire pieces of any one of these chromosomes or involve individual letters (A, T, C, G) on individual genes.

Chromosomal Mutations - Involve changes in the number or structure of chromosomes - Deletion

- Loss of all or part of a chromosome

- Duplication

- Produces an extra copy of all or part of a chromosome

- Inversion

- Reverses the direction of parts of a chromosome

- Translocation

- Part of one chromosome breaks off and attaches to another chromosome

What are some types of mutations? There are many different types:

Chromosomal mutations 1.

Insertion

What are some types of mutations?

2. Deletion

Cri du chat Syndrome

Williams Syndrome

What are some types of mutations? 3. Translocation

What are some types of mutations? 4. Duplication

Point Mutations - Are mutations that involve changes in one or more nucleotides - Occur at a single point in the DNA sequence - Can cause changes to occur further along the DNA molecule from the initial mutation

Point Mutations - Substitution - One nucleotide is changed to a different nucleotide

Sickle Cell Anemia

Point Mutations

- Insertion, Deletion or Substitution - One or more nucleotides are inserted removed or substituted into the DNA sequence

Huntington’s Disease

Muscular Dystrophy

Point Mutations - Frameshift - Mutations that change the “reading frame” of DNA - Change the sequence of DNA from the initial point of mutation

translocation

translocation

* Summary notes about mutations: 1. Mutations can be harmful, lethal or even provide a benefit for the organism 2. Mutations can be "silent". That is, you and your spouse may be carrying mutations that show up only in your offspring. 3. Mutations can accumulate throughout your life depending on the lifestyle you choose, so live wisely!