Ch 14 mutations and Genetic Variation Flashcards
What is the wild type sequence?
The most common that appears
What is a polymorphism?
A variation in the DNA sequence that is too common to be due to mutation. for example SNPs
How can mutations result?
Errors in dna replication, Environmental damage, spontaneous dna decay
What are mutations?
heritable changes in DNA
What are somatic mutations?
Mutations in body cell and is passed from daughter cells but not offspring
What are Germ Line Mutations?
mutations in cells that produce gametes and passed to offspring
What is the effect of a silent mutation?
Changes Amino Acid sequence but not the protein function
What is the effect of a loss of function mutation?
affects protein function and may lead to a loss of function
What is the effect of a gain of function mutation?
Leads to a protein with altered function
What is the effect of a conditional mutation?
Causes phenotypes under restrictive conditions
What is a point mutation?
change in single base pair that results in loss, gain, or substitution
What is a silent point mutation?
A base change results in a changed amino acid but has no effect on the Protein sequence
What is a missense point mutation?
When the base substitution results in Amino Acid change and either disabled, altered, or no effect on the protein
What is a nonsense point mutation?
Base substitution results in stop codon early on
What is a frame shift point mutation?
Single bases are inserted or deleted causing all Amina Acids beyond it to change. Must be something not a multiple of 3.
What are the four types of chromosomal mutations?
Deletion (single chromosome is shorter), Duplication( homologous chromosomes where one is shorter and the other longer), Inversions (one chromosome is flipped), and translocations ( two not homologous chromosomes are joined)
True or False Mutations are Random?
True- like mutations causing resistance are just becoming more common.
How did Lederberg prove mutations are random?
By the culture plates and proving the environment does not induce mutations
Genotype is
The DNA sequence
Phenotype is…
Physical appearance influenced by genotype and environment
What is a Genetic Risk Factor?
a mutation that increases the risk of a particular disease
What does DNA fingerprinting use?
Uses VNTR’s which is number of repeats to see matches like comparing DNA at crime scene to suspects through Gel electrophoresis
What are SNP’s?
Single Nucleotides polymorphism like eye color
What is copy number variation?
Differences among individuals in the # of copies of a region in the genome
Trisomies, Monosomies, and Polyploid
Trisomies are one extra, mono is one less, polyploidy is extra sets
What are the three types of DNA Repair?
Mismatch, base excision, and nucleotide excision
