modern understanding of inheritance Flashcards
how do chromosome pairs migrate
as discrete structures
gametes
gametes are either the egg or the sperm with the same number of chromosomes, as well as equal contribution from each parent
what combines during fertilization
the gametes to create offspring with the same chromosome number as the parents
what do parent gametes do
they synthesize gametes that have half of their chromosomal complements
what traits are inherited together according to TH morgan
the sex and eye color (they do not segregate independently)
what do traits on the same chromosome do
they do NOT segregate independently, they link together
what do traits that are far apart or not on the same chromosome do
they segregate independently
which traits segregate more often
traits thats are farther apart from each other
what type of chromosomes do not separate properly
homologous chromosomes
what is nondisjunction
failure to separate chromosomes
what is trisomy
it is an individual with several copies of one chromosome
Ex: people with down syndrome
what is monosomy
it is an individual with one copy of a chromosome
when is nondisjunction the most serious
it is most serious in meiosis one because ALL of the gametes become messed up
Ex: n-1, n-1, n+1, n+1
what nondisjunctions are embryonic lethal (miscarriage)
trisomies and monosomies
most commonly known trisomy is down syndrome!!!
trisomy 21
1) this possibility increases with mothers age
2) traits are heart defects, poor muscle tone, and eye slanting
3) this is due to nondisjunction!!
