1 Objective: List the types of DNA mutations and their affect on the translation/activation of DNA. http://news.softpedia.com/images/news2/Researchers-discover-how-to-detect-mutations-2.jpg Introns and Extrons Eukaryotes have spans of DNA that do not code for genes, followed by lengths of DNA that do code for genes. Introns are longs segments of DNA that do not code for a gene. Often called “junk DNA”. What good are introns? Exons are spans of DNA that do code for a gene. DNA POINT MUTATIONS POINT MUTATION : CHANGE IN A SINGLE NITROGEN BASE PAIR IN DNA. (EXAMPLE: INSTEAD OF AN “A”, THERE IS NOW A “G”). FRAMESHIFT MUTATION : CAUSED BY THE ADDITION OR DELETION OF A SINGLE NITROGEN BASE. THESE MUTATIONS CAN BE VERY DEADLY.

DNA POINT MUTATIONS - Quia · 2020-04-08 · dna point mutations point mutation : change in a single nitrogen base pair in dna. (example: instead of an “a”, there is now a “g”)

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Page 1: DNA POINT MUTATIONS - Quia · 2020-04-08 · dna point mutations point mutation : change in a single nitrogen base pair in dna. (example: instead of an “a”, there is now a “g”)

Objective: List the types of DNA mutations

and their affect on the translation/activation

of DNA.

http://news.softpedia.com/images/news2/Researchers-discover-how-to-detect-mutations-2.jpg

Introns and Extrons

Eukaryotes have spans of DNA that do not code for genes, followed by lengths of DNA that do code for genes.

Introns are longs segments of DNA that do not code for a gene. Often called “junk DNA”.

What good are introns?

Exons are spans of DNA that do code for a gene.

DNA POINT MUTATIONS

POINT MUTATION: CHANGE IN A SINGLE NITROGEN BASE PAIR IN DNA. (EXAMPLE: INSTEAD OF AN “A”, THERE IS NOW A “G”).

FRAMESHIFT MUTATION: CAUSED BY THE ADDITION OR DELETION OF A SINGLE NITROGEN BASE. THESE MUTATIONS CAN BE VERY DEADLY.

Page 2: DNA POINT MUTATIONS - Quia · 2020-04-08 · dna point mutations point mutation : change in a single nitrogen base pair in dna. (example: instead of an “a”, there is now a “g”)

TYPES OF MUTATIONS

DELETION MUTATIONS: A NUCLEOTIDE IS CUT OUT. EFFECT: CHANGED PROTEIN (FRAMESHIFT MUTATION)

INSERTION MUTATION: A NUCLEOTIDE IS ADDED. EFFECT: CHANGED PROTEIN. (FRAMESHIFT MUTATION)

SUBSTITUTION MUTATION: ONE NUCLEOTIDE REPLACES ANOTHER NUCLEOTIDE IN A STRAND OF DNA. EFFECT: OFTEN LITTLE OR NO CHANGE TO THE PROTEIN.(POINT MUTATION)

http://www.members.cox.net/amgough/Mutation_frameshift-01_03_03d.jpg

http://staff.jccc.net/PDECELL/evolution/mutations/mutypes.gif

Page 3: DNA POINT MUTATIONS - Quia · 2020-04-08 · dna point mutations point mutation : change in a single nitrogen base pair in dna. (example: instead of an “a”, there is now a “g”)

Chromosome Mutations

Sometimes during cell division, chromosomes do not properly separate. This is called a nondisjunctionmutation. Sometimes, instead of one chromosome going to each new cell, one cell get both, while the other gets none.

This can also occur during meiosis, resulting in gametes that have too many or too few chromosomes.

Down’s Syndrome is an example of a nondisjunctionmutation.