Chromosomal Basis of inheritance Flashcards
Chromosome Theory of inheritance
- Mendelian genes have specific loci (sites) along chromosomes
- Chromosomes undergo segregation and independent assortment
Wild Type
normal/most common phenotypes
opposite of mutant type
Fly with red eyes
Mutant Type
least common phenotypes
opposite of wild type
Fly with white eyes
Fathers pass X-linked alleles to:
all of their daughters but to none of their sons
Mothers pass X-linked alleles to:
both sons and daughters
Genetic Map
An ordered list of the genetic loci along a particular chromosome
loci - plural of locus
Recombination Frequency
the farther apart two genes are, the higher the probability that a crossover will occur between them and therefore the higher the recombination frequency
Nondisjunction
Pairs of homologous chromosomes do not separate normally during meiosis
Aneuploidy
occurrence of one or more extra or missing chromosomes in a cell or organism
Results from fertilization of gametes in which nondisjunction occurred
Polyploidy
A condition in which an organism has more than 2 complete sets of chromosomes
Triploidy (3n) is three sets of chromosomes
Tetraploidy (4n) is four sets of chromosomes
Alterations in Chromosome Structure
Deletion
removes a chromosomal fragment
Alterations in Chromosome Structure
Duplication
repeats a segment
Alterations in Chromosome Structure
Inversion
reverses orientation of a segment within a chromosome
Alterations in Chromosome Structure
Translocation
moves a segment from one chromosome to another
