Ch. 12 Flashcards
What is the chromosome theory of inheritance?
- states that genes are located at specific loci on chromosomes
- the behavior of chromosomes during meiosis accounts for inheritance patterns
Who was Thomas Hunt Morgan?
a biologist best known for experimenting with fruit flies and confirming that genes are stored in chromosomes
What chromosomes do males and females have in an x-y chromosome system?
females have xx chromosomes and males have xy
What are sex-linked genes?
- those located on either sex chromosome
- mostly found on the x chromosome and show distinct patterns of inheritance
- very few found on the y chromosome
What is non-disjunction?
an error in cell division where members of a pair of homologous chromosomes or sister chromatids fail to separate properly
What does monosomic mean?
refers to diploid cells that have only one copy of a particular chromosome instead ot the normal two
What does trisomic mean?
refers to diploid cells that have 3 copies of a particular chromosome instead of the normal two
What is polyploidy?
a chromosomal alteration in which the organism possesses more than 2 complete chromosome sets
What are the four types of chromosomal aberrations?
- deletion
- duplication
- inversion
- translocation
What is deletion?
occurs when a chromosome breaks and some genetic material is lost
What is duplication?
occurs when one or more copies of a DNA segment is produced
What is inversion?
occurs when a segment breaks off and reattaches within the same chromosome, but in reverse orientation
What is translocation?
occurs when a piece of one chromosome breaks off and attaches to another chromosome
