14.1 Flashcards
down syndrome
trisomy 21
sister chromatids are identical?
Yes, but not during Meiosis. Crossing-over produces a small in one sister chromatid
nondisjunction
failure of homologous chromosomes (meiosis I) fail to separate, or failure of sister chromatids (meiosis II) fail to separate
this may lead to trisomy or monosomy because the gamete can have only 2 or 0 copies of a given chromosome
Turner’s syndrome -> 1 X chromosome
incomplete dominance
PINK roses
codominance
BLOOD types
pleiotropism
expression alters many different unrelated aspects of total phenotype (mutation -> influences development of heart, bones, and ear)
polygenism
HEIGHT
complex traits
penetrance
ex. Neurofibromatosis type I
high, incomplete, or low
the likelihood a person with a genotype will express the expected phenotype (100% if the penetrance is perfect)
epistasis
BALDNESS
when one gene impacts the expression of another
linkage
failure of Independent assortment
genes on same chromosome
recombination frequency (calculate)
recombinants / total number of offspring
smaller recombination frequency =
closer the genes are
inheritance patterns (DRAW - p. 344 table)
autosomal recessive - two copies -> youth autosomal dominant - 1 copy = disease mitochondrial Y-linked X-linked recessive X-linked dominant
X-linked
HEMOPHILIA - x-linked recessive
Colorblindness -x-linked recessive
X-linked dominant -> still affects men more than women? the dominance is not complete?
MALES DO NOT RECOMBINE ON THE X-CHROMOSOME!
Hardy-Weinburg assumptions (MMNsRmL)
- No mutation
- No migration
- no Natural selection
- Random mating
- Large population size
MMNsRmL
fitness (genetics)
how successful an organism can pass its alleles to future generations
evolution is driven by…
multiple alleles with differential fitness
mutations causes change in alleles
species
defined as ability to produce fit offspring
population versus species
species CAN mate, population DO mate
prezygotic (4 types)
prevents formation of hybrid zygote
- temporal - different mating times
- behavioral - mating rituals
- mechanical - reproductive structures or genitalia are not compatible
- gametic - sperm-egg do not recognize each other
postzygotic barriers (3)
- hybrid inviability - death of offspring in embryonic stage
- hybrid sterility
- hybrid breakdown - two mules mate but their offspring are inviable
analogous versus homologous
homologous - same ancestral line, different phenotype
analogous - different ancestral lines, same phenotype
genus and species
G and s
taxonomy table (DRAW - p. 352)
draw
abiotic synthesis
no enzymes around, but metals and clay were catalysts, producing proteinoids
protobionts
droplets of proteinoids - microspheres
liposomes - lipids added
coacervate - polypeptides, NAs, polysaccharides -> can catalyze reactions
