HYS - CH12.3 - Analytical Approaches In Genetics Flashcards
Monohybrid
One trait is being studied
Parent or P is the crossed generation
Offspring are F or filial generation
Uses subscripts for generations
Monohybrid cross creates what genotypes and what phenotypes
100% Pp genotype and P phenotype
Crossing two heterozygotes for a trait with complete dominance results in what genotype and what phenotype ratio?
Genotype
1:2:1
PP, Pp, pp
Phenotype
3:1
Test cross (back crosses determines parent genotype based on phenotype of offspring)
Determines the unknown genotype
Organism with unknown genotype is crossed with an organism known to be homozygous recessive
If 100 percent are dominant, unknown is likely homozygous dominant
If 1:1 or split of dominant to recessive phenotypes then the unknown is likely heterozygous
Dihybrid cross with complete dominance
What if we cross 2 plants which are heterozygous for 2 traits?
Inheritance of two different genes
Remember inheritance of one gene is independent from inheritance of another gene (unlinked genes)
If we use P and p for purple
And T and t for height
Crossing 2 plants which are heterozygous for 2 traits
Phenotypic ratio 9:3:3:1
9 tall and purple, 3 tall and white, 3 dwarf and purple, 1 dwarf and white
3:1 phenotypic ratio exists for each trait (12 tall 4 dwarf and 12 purple 4 white
Sex linked crosses
What do we use for a disease carrying allele on X chromosome?
Females have 2 X chromosome and can be heterozygous (carrier) or homozygous for a condition
Males are hemizygous for X linked conditions as they have 1 X chromosome
Xh for disease carrying allele
What are the genotyping and phenotypic ratios of crossing carrier female of X related disorder and normal male
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What are the genotypes for cross between carrier female and hemophiliac male?
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What is a Chiasma and gene separation? What is recombination frequency?
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What is a genetic map, map unit, centimorgan?
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Allele frequency
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Hardy Weinberg principle assumptions
X
What is hardy Weinberg equation and what does it stand for?
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If a plant pop has pea plant frequency of T allele as 0.8 what is the frequency of the short allele, heterozygous dominant, homozygous recessive, and dominant phenotype (homozygous and heterozygous dominant genotypes)?
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why type of zygosity is in the figure?
hemizygous
zygosity
degree of similarity of DNA between homologous chromosomes at a gene locus
Loci A, B, C are on the same chromosome. What could represent a chromosome of cell with genotype AABbcc?
since genotype is AABbcc
AA shows dominant A
Bb shows recessive b and dominant B
cc shows 2 recessive c
two combinations can be
ABc or
Abc
depends on if B is recessive or dominant
which blood types show codominance
when both AB are present
AB- and AB+
which events happen in mitosis and meiosis?
DNA replication (interphase in meiosis)
spindle formation
chromosmal segregation
what events occur in meiosis and not mitosis?
synapsis (when homologous chromosomes pair up in prophase I meiosis),
recombination (crossing over in prophase I meiosis) and
reduction division only occur in meiosis bc in the second division it takes 1 female inherited daughter cel (2n) and 1 male inherited daughter cell (2n) and reduces chromsomes in half of each making 4 daughter cell, 2 hapliod with female sister chromatid and 2 hapliod with male sister chromatid
polyalleism
presence of multiple alleles at a gene locus
shows aaBBCc
which sister chromatids exhange genetic material?
the NON sister chromatids (across female and male) in meiosis
centriole vs centromere
centromere holds sister chromatic together
centriole is a protein structure tha forms poles and pulls sister chromatid
which is an example of codominance and which is an example of imcomplete dominance
-dominant BB for black
-recessive bb for white
- offspring with grey (Bb)
- offpsring with spots of black and white (Bb)
incomplete dominance - intermediate phenotype of heterozygous offspring
- offpsring with grey hair (Bb)
complete dominance - both alleles are dominant
- offpsring with black and white hair (Bb)
