Term
interference
&
coefficient of coincidence
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Definition
| the degree to which one crossover interferes with additional crossovers in the same chr/mal region |
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Term
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Definition
| 1X chromosome per call condenses into a compact object |
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Term
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Definition
| males develop from unfertilized eggs (haploid), while females develop from fertilized eggs (diploid) |
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Term
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Definition
-some plants and animals
--lacking sex chromosomes
---a single individual produces sperm and egg (HERMAPHRODITIC) |
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Term
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Definition
| not sex-linked, expressed only in one sex (ex milk production, egg laying, oviposition) |
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Term
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Definition
| genotypes, determined by autosomal genes, are expressed differently in the two sexes |
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Term
| recombination frequency (r) |
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Definition
[number of recombinants]
------------------------------------ x 100%
[total number of testcross progeny] |
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Term
When genes are far apart on a chr/me:
observed frequency of recombination is [smaller/greater than/equal to] expected frequency of recombination? |
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Definition
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Term
| Why 3 point crosses are more efficient for gene mapping: |
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Definition
| 2 point test crosses - too many of them are needed to map relatively few genes, and double crossovers are missed (thus underestimating recombination rate) |
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Term
| expected frequency of double cross-overs: |
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Definition
| [rec. freq. of region 1 / 100] x [rec. freq. of region 2 / 100] |
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Term
| gene mapping with molecular markers |
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Definition
-physical mapping (sequencing) is the ultimate mapping
-molecular markers in whole genome and gene mapping |
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Term
| chi (x) squared test of independence |
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Definition
| x^2 = (sum) [(observed-expected)^2 / expected] |
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Term
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Definition
| =(number of rows - 1) x (number of columns - 1) |
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Term
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Definition
| genes are not assorted independently |
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Term
| genomes can be altered by large scale alterations to: |
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Definition
-chromosome structure
or
-number of chromosomes |
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Term
| chromosomal changes in structure |
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Definition
| result of chromosomal breaks and abnormal rejoining |
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Term
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Definition
| when a chromosomal segment is represented twice |
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Term
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Definition
| karyotype for heterozygous mutation in chromosome |
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Term
| deletion of a chromosomal segment |
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Definition
| loss of chromosomal segment |
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Term
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Definition
| pairing of homologous chromosomes (in meiosis) |
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Term
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Definition
abnormal homologue pairing in meiosis
--deletion mutants do not revert |
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Term
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Definition
| when RECESSIVE alleles on normal chromosome affect phenotype |
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Term
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Definition
up to 1000x the size of corresponding chromosomes at meiosis or in somatic cells
--products of repeated chr'me duplications w/o cell division |
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Term
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Definition
alterations in sequence of genes on a chr/me
--a 2-point break followed by incorrent rejoining |
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Term
| Robertsonian Translocation |
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Definition
| fusion of 2 acrocentric chromosomes in centromere region |
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Term
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Definition
| the number of single sets of chromosomes in cell/organism |
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Term
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Definition
| refers to the # of chromosomal sets |
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Term
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Definition
| # of a particular chromosome is not the same as the ploidy number (for the species) |
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Term
| Nondisjunction in mitosis |
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Definition
| mosaics of normal & "affected" cells (in the individual) |
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Term
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Definition
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