Biology Lesson 9: Genetics, Part 2 Flashcards
Structural genes:
responsible for coding outward appearance and inward components of a person’s cells
Regulatory genes:
code for the proteins which turn genes on and off
Mutations:
errors in the genetic code
Translocation:
occurs when broken peices of chromosome attach to the wrong chromosome
Deletion:
occurs when a segment of a chromosome breaks off and is lost
Inversion:
occurs when a segment breaks off and reattaches in the correct place, but inverted- upside down
There can be errors in the genes called
point mutations, these occur when one or more nucleotide in the sequence
Substitution:
occurs when a nucleotide is removed and replaced with a different nucleotide
Addition:
occurs when an extra nucleotide is placed in the sequence causing a frame shift, when all the nucleotides in the DNA are shifted down by one.
Deletion:
occurs when a nucleotide is removed from the DNA causing a frames shift
There can be aneuploidy mutations:
the presence of an abnormal number of chromosomes
2 types of aneuploidy mutations
Trisomy, Monosomy
Trisomy
instead of a homologous pair, there are three chromosomes
Monosomy
instead of a homologous pair, there is just one chromosome
Example of trisomy
Down syndrome