Midterm 1 Flashcards
dihybrid cross
cross between two organisms with different variations at 2 locuses
monohybrid cross
cross between two organisms with different variations at 1 locus
mitosis
somatic cells, results in 2 diploid genetically identical daughter cells, PPMATC
diploid
cell with 2 sets of chromosomes, 1 from each parent
prophase
chromosomes condense, centrosomes migrate to opposite poles and release microtubules
prometaphase
microtubules attach to chromosome and nuclear envelope breaks down
metaphase
chromosomes align at middle of cell
anaphase
sister chromatids separate to opposite poles
telophase
nuclear envelope reforms, chromosomes decompress
cytokenesis
division into 2 daughter cells
sister chromatids
replicated chromosome
homologous chromosomes
2 pairs of sister chromatids with genes at the same location
meiosis
germ and sex cells, results in 4 haploid genetically unique daughter cells
prophase I
chromosomes condense, undergo synapsis, each pair forms bivalent with 2 sister chromatids
synapsis
pairing up of homologous chromosomes and swapping of alleles
prometaphase I
spindle attach to kinetochores on chromosomes
metaphase I
homologous pairs line up at middle of cells
anaphase I
pairs separate but sister chromatids do not
telophase I and cytokinesis
chromosomes gather at opposite poles, cytoplasm divides, 2 haploid cells
meiosis II
same process as mitosis
null/amorphic alleles
recessive, nonfunctional protein produced or no protein
hypomorphic alleles
recessive, poorly functioning or less amounts of normal functioning protein produced
hypermorphic alleles
dominant, over production of protein or production of protein with increased activity
neomorphic/negative alleles
dominant, protein has new function or interferes with wildtype protein
G2 of interphase
before prophase, DNA doubles
incomplete dominance
BB Bb and bb all differ phenotypically, Bb is between both
codominance
BB Bb and bb all differ phenotypically, Bb exhibits phenotypes of both
recessive lethal alleles
essential genes when mutated lead to lethal phenotype, YY, both big Y required to be lethal, 2:1
penetrance
proportion of individual organisms having a particular genotype that express the expected phenotype
dominant lethal alleles
only one big Y required to be lethal
expressivity
degree to which phenotype is expressed
complete penetrance
identical know genotypes yield 100% expected phenotype
incomplete penetrance
identical know genotypes produce <100% expected phenotype
constant expressivity
identical known genotypes with no expressivity effect yield 100% expected phenotype
variable expressivity
identical know genotypes with an expressivity effect yield a rang of phenotypes