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Definition
| the heterozygote simultainiously expresses the phenotype of both homozygotes |
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Term
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Definition
when a genotype does not produce the expected penotype
ex:extra fingers and toes |
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Term
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Definition
| the percentage of individuals having a particular genotype that expresses the expected phenotype |
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Term
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Definition
the degree to which a character is expressed
ex: full extra fingers vs. a tag of skin |
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Term
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Definition
causes death at an early stage of development
often before birth
so some genotypes may not appear amoung the porogeny |
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Term
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Definition
more than two alleles are present within a group of individuals
the locus has multiple alleles |
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Term
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Definition
| Products of genes at different loci combine to produce new phenotypes that are not predictable from the single-locus effects alone. |
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Term
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Definition
the masking of gene effects of a gene located on different loci
epistatic gene - does the masking
hypostatic gene - the masked gene
in Dominance the masking is on the same locus |
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Term
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Definition
Test designated to determine whether two different mutationsare at the same locus or at a different loci.
2 individuals that are homozygous for two independently derived mutations are crossed, producing F1's that are heterozygous for the mutations. If the mutations are at the same loci, the F1 will have a mutant phenotype. If the mutations are at a different loci, the F1 will have wild-type phenotype. |
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Term
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Definition
| 2 different mutations in the heterozygous condition are exhibited as a wild-type phenotype; indicates that the mutations are at different loci. |
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Term
| sex-influenced characteristic |
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Definition
determined by autosomal genes and are inherited according to Mendel's principals, but they are expressed differently in males and females
ex:baldness - males only need one recessive allele, females need both recessive alleles to show baldness |
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Term
| sex-limited characteristic |
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Definition
encoded by autosomal genes that are expressed only in one sex, the trait has zero penatrance in other sex
ex: breast size is not expressed in males |
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Term
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Definition
| characteristics are encoded by genes located in the cytoplasm |
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Term
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Definition
| Genes are inherited by both parents, but the offsprings phenotype is determined not by its own genotype, but by the genotype of the mother |
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Term
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Definition
the differential expression of genetic material depending on weather it is inherited from the male or female parent
ex:gene Igf2/effects fetal growth in mice |
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Term
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Definition
| due to alterations in DNA that do not include changes in the base sequence,often affect the way the DNA sequence in expressed |
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Term
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Definition
| the range of phenotypes produced by a geneotype in different enviornments |
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Term
| tempreature-sensitive alleles |
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Definition
an allele whose product is functional only at certian temperatures
ex: himalayan allele in rabbits |
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Term
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Definition
| when enviornmental factors alone can produce a phenotype |
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Term
| discontinuous characteristics |
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Definition
a few easily distingushed phenotypes
ex: round or wrinkled peas |
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Term
| continuous characteristic |
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Definition
characters that exhibt a continuous distribution of phenotypes
ex:human height
"quantitative characters" |
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Term
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Definition
| characteristics encoded by genes at many loci |
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Term
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Definition
| one gene affects multiple characteristics |
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