Mod 6 IQ 6 Flashcards
Electromagnetic radiation sources
Radiation can damage the DNA and the cell cycle
ionizing radiation can break DNA molecules, damage bases, and cause base and larger chromosomal and cross linin of DNA
Most of this damage can be repaired through continued exposure can increase the risk that damage cannot be repaired
Chemical mutations
chemical mutagens cause changes to DNA nucleotide bases or to the three-dimensional structure length. In many cases, the mutagens were discovered because of its role as a carcinogen
What is an example of electromagnetic radiation
The UV light, X rays, and gamma rays
What is an example of a chemical mutation
Nitrogen mustards from world war 1 and 2
produce mutation by adding small hydrocarbon groups, such as methyl groups, to either the bases or the backbone phosphate groups of DNA
Naturally occurring mutagens
Natural occurring mutagens may physically or chemically promote mutations. Historically naturally occurring mutagens have often been detected and investigated because they correlate strongly with the increased incidence of cancer
What is an example of naturally occurring mutagen
Reactive oxygen species (ROS) results in a mutagen attached to nitrogenous bases, as well as DNA strand breaks and crosslinks
Source of it is could be the mitochondria and or exposure yo pollutants like tobacco smoke, or radiation and plants
Point mutation
is a change in one nucleotide in a DNA
when one base is substituted for another with sufficient frquency it will result in an (SNP)
Chromosomal mutation
occurs when a cell is undergoing cell division. It can also occur as a result if exposure to ionizing radiation
What are the four types of chromosomal rearrangements
Deletion occurs when a chromosome breaks and a section of a chromosome is lost
Duplication occurs when a section of a chromosome is copied and added
Inversion occurs when a section of chromosome breaks free, reorients and re-joins in reverse order
Translation occurs when a section of chromosome breaks odd but rejoins a different, non-homologous chromosome
Somatic mutation
somatic mutations in the osmatic or normal body cells that occur in an individual after contraception but are not passed onto the offspring
Germline mutation
Germline cells are the gametes that carry DNA and genes through fertilization to the next generation zygote
Coding DNA
coding sections of DNA segments comprise the gene that are templates for the formation of polypeptides
Noncoding DNA
regulation of gene expression. The impact of mutations in ‘non-coding’ segments can range from having no effect on preventing polypeptide synthesis hence some protein functions
if the noncoding DNA that experiences a mutation is promoter sequence, DNA polymerase may not be able to bind, thereby preventing transcription of a polypeptide
What is the cause of genetic variation relating to the processes of fertilization, meiosis, and mutation
fertilization allows for new combinations of alleles
Meiosis through random segregation causes new combinations of chromosomes and hence alleles
als crossing over which gives new combinations of alleles along chromosomes
Mutation produces new alleles and changes in gene regulation and expression or chromosome number arrangement
What are the outcomes of of a mutation occurring in the coding DNA
Silent mutation a different mRNA codon bt the same amino acid is inserted into the polypeptide there is no change in phenotype.
Missense mutation a mutation may result in a different amino acid in the polypeptide sequence
The nonsense mutation results in the substitution of a stop codon resulting in a shorter polypeptide chain hence becoming a dysfunctional protein
