Term
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Definition
| Probability(2 independent events occur together) = p(1) x p(2) |
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Term
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Definition
| Probability(either of 2 mutually exclusive events occurs) = p(1) + p(2) |
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Term
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Definition
| experiment involving hybrids for a single trait |
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Term
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Definition
| alternate forms of a single gene |
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Term
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Definition
| individual showing dominant phenotype crossed with individual expressing the recessive phenotype to discover genotype of dominant (Yy or YY) |
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Term
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Definition
| individual heterozygous for two genes at the same time, AaBb |
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Term
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Definition
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Term
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Definition
Parents: AABB x aabb. Make AB and ab gametes.
F1 are all AaBb, make AB Ab aB ab games. 9:3:3:1 ratio A-B- to aaB- to A-bb to aabb.
A-B- and aabb are parents
aaB- and A-bb are recombinants |
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Term
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Definition
AaBbCcDdEeFf x AaBbCcDdEeFf
do each one independently
1/4 x 1/4 x 2/4
etc. |
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Term
| pedigree- vertical pattern of inheritance |
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Definition
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Term
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Definition
| hybrid does not resemble either pure breeding parent ex white x purple yields green |
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Term
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Definition
hybrid shows traits from both pure breeding parents
ex white x red yields pink |
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Term
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Definition
| number of alleles divided by total number of alleles in the population |
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Term
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Definition
most common allele in a population
designated by + |
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Term
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Definition
| rare allele in same population |
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Term
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Definition
| gene with only one common wild-type allele |
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Term
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Definition
genes with more than one common allele
ex blood type-- IA, IB, i all have large frequencies in population |
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Term
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Definition
| single gene determines a number of distinct and seemingly unrelated characteristics |
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Term
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Definition
homozygous recessive leads to death
allele still persists in population due to heterozygote carriers |
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Term
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Definition
homozygotes survive birth and die later
Tay-Sachs |
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Term
| complementary gene action |
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Definition
| two genes work together to produce a trait--must both be present. 9:7 |
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Term
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Definition
| allele at one gene masks the effects of alleles at another gene |
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Term
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Definition
9:3:4
homozygous recessive, bb, masks the effects of Bb or BB |
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Term
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Definition
12:3:1--B masks any A or a. need bb and any A or a
13:3--need A- and bb |
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Term
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Definition
| mutation at any of several genes gives same mutant phenotype |
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Term
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Definition
cross between two identical recessive phenotypes from different lines
if the offspring has the wild-type phenotype, or NO mutation, then complementation HAS occurred meaning the original mutations of the parents were on two separate genes and each parent contributed an allele that would cancel the other parent's mutant allele out
will not work if the mutant allele is dominant to the wild-type allele |
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Term
| penetrance vs expressivity |
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Definition
| penetrance is how many members of a population with a particular genotype show the expected phenotype. expressivity is the intensity with which a particular genotype is expressed within a phenotype, like if one eye or both eyes are affected |
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Term
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Definition
| alter phenotypes produced by alleles of other genes |
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Term
| Conditional lethal mutations |
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Definition
lethal only under certain conditions
Permissive conditions - mutant allele has wild-type functions!
Restrictive conditions - mutant allele has defective functions |
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Term
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Definition
| phenotype arising from an environmental agent that mimics the effect of a mutant gene |
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Term
| metacentric vs acrocentric centromere |
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Definition
metacentric: chromosome is in the middle
acrocentric: chromosome is near one end |
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Term
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Definition
n=23
2n=46
at metaphase of mitosis: 23 homologous pairs
somatic cells are diploid, gametes are haploid |
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Term
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Definition
| have the same genes but may have different alleles for those genes |
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Term
| Humans: XXX, XX, XO, XY, XXY, XYY, YO |
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Definition
XXX: nearly normal female
XX: normal female
XO: Turner syndrome, webbed neck
XY: normal make
XXY: Klinefelter male- sterile
XYY: nearly normal male
YO: dies |
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Term
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Definition
| gap 1 (G1) phase, synthesis (S) phase, and gap 2 (G2) phase • Period of cell growth and chromosome duplication between divisions • Formation of microtubules in cytoplasm |
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Term
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Definition
microtubule organizing center near
the nuclear envelope |
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Term
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Definition
core of centrosome, not found in
plant cells |
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Term
| most of cell growth occurs |
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Definition
Most of cell growth occurs
during G1 and G2 phases |
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Term
Chromosomes replicate to
form sister chromatids |
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Definition
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Term
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Definition
| chromosomes condense from tangle of chromatin present in interphase and become visible |
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Term
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Definition
spindle forms and sister chromatids attach to microtubules from opposite centrosomes
nuclear envelope breaks down |
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Term
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Definition
| chromosome align at the cell's equator! |
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Term
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Definition
sister chromatids separate and move to opposite
poles |
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Term
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Definition
chromosomes decondense and are enclosed in
two nuclei |
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Term
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Definition
precursors to gametes
Set aside from somatic cells during embryogenesis
Become incorporated into reproductive organs
Only cells that undergo meiosis produce haploid gametes |
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Term
| when do chromosomes duplicate in meiosis and when does the nuclei divide? |
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Definition
| chromosomes duplicate at beginning of meiosis 1 and nuclei divide in both meiosis 1 and meiosis 2 |
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Term
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Definition
1. Homologs pair, exchange parts, and then segregate
2. Sister chromatids remain intact at centromere throughout meiosis I
3. Maternal and paternal homologs
recombine
4. After recombination, homologous chromosomes (not chromatids) segregate to different daughter cells (chromatids still attached at centromere) |
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Term
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Definition
Condensation of chromatin
pairing of homologs
reciprocal exchange of genetic information between homlogs |
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Term
| crossing over occurs during |
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Definition
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Term
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Definition
| 2 pairs of homologous chromosomes--sister chromosomes have crossed over but each pair of homologs has its own centromere |
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Term
| metaphase 1 and anaphase 1 |
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Definition
| tetrads line up in middle then homologs separate to opposite sides of the cell. sister chromosomes are NOT separated |
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Term
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Definition
occurs after meiosis 1
similar to interphase but NO CHROMOSOME DUPLICATION |
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Term
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Definition
very similar to mitosis, sister chromatids separate to opposite ends of cell
resulting 4 daughter cell are haploid because at end of meiosis 1 the 2 daughter cells only have one set of homologous chromosomes |
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Term
| Mendel’s law of independent assortment is best physically explained by |
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Definition
| Independent alignment of different pairs of homologous chromosomes during metaphase of meiosis I |
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Term
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Definition
occurs with x-linked recessive genes
daughters get phenotypes of fathers and sons get phenotypes of mothers |
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