Cytogenetics Flashcards
(31 cards)
Refers to the presence of three or more haploid sets of chromosomes
Polyploidy
Usually not viable. Inability to synapse and form tetrads impairs meiosis
Animal Polyploidy
Plant Polyploidy: sometimes these are viable because plants can use ___ chromosomes are copied, but a cytoplasmic division does not occur
Somatic doubling
All chromosome sets from the same species (double fertilization)
Autopolyploidy
Two different species contribute to the extra chromosomes
Allopolyploidy
Failure to separate
Non-disjunction
The process of meiosis in mammalian females is halted until the onset of ___
Puberty
The result of non-disjunction of homologous chromosomes during meiosis
Aneuploidy
Half missing a chromosome
Monosomy
If non-disjunction occurs during ___, all four gametes are defective
Anaphase I
Half have an extra chromosome
Trisomy
If non-disjunction occurs during ____, half of the gametes would be normal
Anaphase II
___ leads to spontaneous abortion
Autosomal Monosomy
Most ___ leads to spontaneous abortion
Autosomal Trisomy
___ causes Patau Syndrome
Trisomy 13
___ causes Edwards Syndrome
Trisomy 18
___ causes Down Syndrome
Trisomy 21
Mental development stalls at 6 month stage; small or fused eyes, cleft palate, kidney and heart abnormalities
Patau Syndrome
Mental development stalls at 6 month stage; heart and liver defects; clenched fists
Edwards Syndrome
Mild to moderate mental retardation; short stature, broad hands, epicanthal eyelids
Down Syndrome
Female: Karyotype is 45, XO
Short, less breast tissue, infertile (amenorrhea)
No Barr bodies
Turner’s Syndrome
Male: Karyotype is 7, XXY
Tall, less body hair, less muscular, infertile
1 Barr Body
Klinefelter’s Syndrome
Errors of crossing over
Structural Aberrations
Chromosome breaks, reattaches in the wrong place. Results include chromosomes with 2 copies of the same allele or missing an allele
Deletions and Duplications
