18.3: Mutations and Genetic Recombination Flashcards
What is a Mutation?
A permanent change in the genetic material of an organism
How are all mutations heritable?
They can be copied during the replication process and passed down to daughter cells. Only mutations that affect gametes are passed down to offspring
What are Somatic Cell Mutations?
Mutations that occur in the body cells
What are Germ Line Mutations?
Mutations that are passed from one generation the next and occur in reproductive cells
What are Mutations?
Small changes in the nucleotide sequence
What is a Point mutation?
A chemical change that affects one or a few nucleotides
What may happen in a Point mutation?
One nucleotide may be substituted for another or there may be an insertion and deletion of a nucleotide
How might a point mutation by substitution affect a cell?
It will have a minor effect on the metabolism of the cell because it may not affect the coding of the protein
What is Silent mutation?
A mutation that has no effect on the cells metabolism
What is a Mis-sense mutation?
A mutation that results in an altered protein
How can a Mis-sense mutation be harmful?
It can change the sequence of polypeptides. This can be seen in sickle cell disease
What is a Nonsense Mutation?
A mutation that renders a gene unable to code for a functional polypeptide ex. codes for a stop prematurely
What is Frameshift mutation?
A mutation that causes the entire reading frame to be altered
Why do Substitution mutations not affect the entire frame?
Because they only substitution one nucleotide in for another
What are many Mutations caused by?
Molecular interactions that take place naturally within cells
What are Spontaneous Mutation?
Mutations that are caused by molecular interactions that take place naturally within cells
What is one source of spontaneous mutation?
Incorrect base pairing by DNA polymerase during replication
What are Induced Mutations?
Mutations that are caused by agents outside the cell
What are Mutagens?
The substance or event that increases the rate of mutation in an organism
What are the two type of Mutagens?
Physical and Chemical
How do X-rays affect DNA?
They tear through DNA molecules causing random changes therefore X-rays are physical mutagens
Why a Physical Mutagens known as Physical Mutagens?
Because they cause physical changes in the structure of DNA
How does UV light affect cells?
It can cause a chemical reaction between C and T bases, resulting in the distortion of the DNA molecule, that interferes with replication
What is a Chemical Mutagen?
A molecule that can enter the nucleus of the cell and induce mutation by reacting chemical with DNA
How do Chemical Mutagens affect DNA?
They may insert itself into the DNA molecule causing a substitution or frameshift
How do other Chemical Mutagens affect DNA?
They have structure similar to but with different base pairing properties which can cause incorrect nucleotides to be inserted during DNA replication
What are most Chemical mutagens?
Carcinogenic
What is cancer in Molecular terms?
The result of somatic cell mutations that disrupt the expression of genes that regulate the cell cycle
What are most cancers caused by?
Combinations in mutations
What are the exceptions to the idea that DNA is universal?
Mitochondria and Chloroplasts have different DNA
What supports the theory that organelles were once independent cells?
The ability for mitochondrial and chloroplasts DNA to be different and synthesized differently
What is the Endosymbiont theory?
The idea that different organelles used to be single cells
What is mtDNA?
Mitochondrial DNA
Whose mtDNA is yours identical to?
Yo mama
What part of DNA has a higher rate of mutation?
Non-coding stretches DNA
What is genetic engineering?
When researchers can manipulate genetic material to alter genes
What is Recombinant DNA?
Genetic material from different sources
What do Restriction Enzymes do?
Catalyze the cleavage of DNA at specific nucleotide sequences
What are Restriction endonucleases?
A Restriction enzyme of an that cts within the interior of a DNA molecule
What do Restriction Nucleases do?
Recognize short sequence nucleotides (called a target sequence) and cut the particular strand
Why are restriction Nucleases so important to researchers?
Because their cuts are predictable and specific. And the create staggered cut at the end which are unpaired nucleotides (sticky ends), so they can bind with other cuts
What is Gel Electrophoresis used for?
Seperating molecules according to their mass and charge
How does Gel Electrophoresis work?
A solution containing DNA fragments is is applied to one end of the gel. When an electric current is passed through because DNA is more negative, it moves towards the positive end of the. Smaller fragments move quicker.
What is a DNA Fingerprint?
The outcome of Gel Electrophoresis, where DNA is separated based on charge.
