Genetics !! Flashcards
What is a mutation?
A change in the sequence of bases in DNA
Name different types of mutation?
Insertion, substitution and deletion
Describe a substitution mutation?
A single nucleotide changes in a codon, DNA is degenerate so the codon could remain the same. Can be catastrophic or just the same
What is a point mutation?
If only one nucleotide is affected
Depurination?
The loss of a purine base
What does an insertion and deletion lead to?
Frameshift mutation, it will change every codon
Different effects of mutations?
No effect, damaging non-functional proteins, or beneficial
What increases the rate of mutation?
Mutagen - a chemical, physical or biological agent
Depyrimidine?
The loss of a pyrimidine
What examples can affect the structures of nucleotides?
Free radicals, oxidizing agents and antioxidants
Inversion mutation?
A section of chromosome breaks off, is reversed, and then joins back onto the chromosome
Translocation mutation?
A section of one chromosome breaks off and joins another non-homologous chromosome
Difference between heterochromatin and euchromatin?
Heterochromatin = tightly wound DNA causing it to be less accessible and inactive genes.
Euchromatin = loosely wound DNA with accessible and active genes
Why is gene regulation required?
It is required for cells to specialize and work in a coordinated way
What is transcriptional gene regulation?
Transcriptional = Genes turned on and off
Post - transcriptional = mRNA can be modified which regulates translation and types of proteins produced
