Mutations Flashcards
(13 cards)
What is a mutation?
A spontaneous change in the nucleotide sequence of the DNA molecule. It is capable of producing a new phenotype starting from a preexisting one.
Are all mutations transmitted through generations?
-Only mutations in germ cells gametes are transmitted to the coming generations
-Mutations affecting somatic cells are not transmitted through generations.They are either corrected or transformed into a cancerous tissue
-Mutations may arise from errors in replication or from stressful and environmented factors
What are chromosomal mutations?
affect number of structure of chromosomes
What are gene mutations?
affects the nucleotide sequence of a gene
What are point mutations? and its types?
affect a nucleotide
1) Substitution mutation
2) Deletion mutation
3) Insertion mutation
What are segment mutations?
affect a sequence of nucleotides
What are substitution mutations and its types?
The exchange of one singular nucleotide by another it could lead: 1) missense mutation
2) nonsense mutation
3) silent mutation
What is a missense mutation?
The change of one nucleotide changes only one amino acid.
What is a nonsense mutation?
The change of one nucleotide leads to a stop codon, and hence a senseless peptide.
What is a silent mutation?
The change of one nucleotide doesn’t affect the amino acid sequence.
What is a deletion mutation?
The removal of one nucleotide that leads to frame shifting
What is an insertion mutation?
The addition of one nucleotide that leads to frame shifting
As a consequence what does the mutation of the DNA sequence effect?
a mutation alters the DNA sequence changing the mRNA and consequently the a.a. sequence may change which may cause a change in the 3D confirmation and structure or the synthesized protein and thus altering its function
