quiz 10 transmission genetics Flashcards
phenotype
outward appearance
allele
one version of a gene
uppercase letter A
dominant allele
lowercase letter a
recessive allele
genotype Aa
combination of genes/alleles carried
every mendelian cross begins with _______ parents
true breeding
parental variety seen in the f1 progeny is considered the ______ trait
dominant
parental variety that is absent in the f1 progeny is considered the _____ trait
recessive
f2 progeny distribution
3/4 dominant, 1/4 recessive
Po: PP (______ dominant) Pp (______ recessive)
F1: Pp (_______)
F2: PP (_______ dominant) Pp/pP (_______) pp (_____ recessive)
homozygous dominant; homozygous recessive; heterozygous
homozygous dominant; heterozygous; homozygous recessive
A mendelian cross always begins with _________
true breeding parents
There are at least three generations in a mendelian cross - what are the three?
The parental, F1, and F2
The dominant and recessive variations of a trait can be determined with which generation?
F1 generation
What ratio is seen in the F2 generation, what is it indicative of?
3:1 ratio, indicative of the segregation of two alleles
Mendelian theory - what part of mendelian theory challenged preformation?
females and males contribute equally to the offspring - preformation states that every gamete carried a potential child
Mendelian theory - what part of mendelian theory challenged blending?
recessive traits were not irreversibly blended together - blending states that the offsprings characteristics were an average between two parents
incomplete dominance
not all dominant alleles produce a fully dominant phenotype
incomplete dominance - full phenotype, half phenotype, no phenotype present
FF, Ff, ff
in an incomplete dominant mendelian cross, what does the F1 generation consists of?
Ff, heterozygous, split phenotypes
in an incomplete dominant mendelian cross, what does the F2 generation consist of?
a ratio of 1:2:1, instead of 3:1
co-dominance
a case where there is more than 1 possible dominant allele
codominance - mixing and creation of a new _________
dominant - heterozygous is completely new phenotype
a dominant allele is almost always an allele that ________ a product. A ________ allele does not
produces; recessive
_______ and ________ alleles have similar inheritance patterns, but they can be distinguished by understanding how each allele is producing or failing to produce a product
incomplete and co-dominant
What do we call the phenotype(s) seen in the F1 generation?
dominant
Random cross: which is the dominant trait?
NO WAY TO TELL RANDOM CROSS
What is the genotype of the F1 generation in a Mendelian cross?
Heterozygous
What is the genotypic ration of the F2 generation in a monohybrid mendelian cross?
1:2:1
what phenotypic ratio would you expect to see in the third generation of a human family?
1:1
You find a brown female (agouti) rabbit and take it home. How could you determine its genotype?
perform a test cross
What is the genotype of the F1 generation as it refers to incomplete dominance?
Heterozygous
What is the distribution for the F2 generation of a incomplete dominance cross?
1/4 AA, 1/2 Aa, 1/4 aa
What does incomplete dominance tell us about these alleles?
The dominant produces a product but the recessive does not. The intermediate phenotype is a result of reduced dosage
Codominance
No true recessive, neither allele is necessarily dominant over the other
What is the result of this codominant cross? ArAr x AbAb
ArAb - F1
What is the result and distribution of this codominant cross? ArAb x ArAb
1/4 ArAr, 1/2 ArAb, 1/4 AbAb - F2
What is suggested by “two dominant alleles?”
both alleles make a functioning product but the products differ from one another. The mixing of the two products creates the intermediate phenotype
Which type of inheritance best describes the patterns in this cross?
P: White x Red
F1: All have Red
F2: 1/4 white, 3/4 red, 3:1 ratio
fully dominant allele
which type of inheritance best describes the patterns in this cross?
P: White x Red
F1: Pink
F2: 1/4 white, 1/2 pink, 1/4 red
co-dominance
which type of inheritance best describes the patterns in this cross?
P: yellow x red
F1: both red and yellow spots
f2: 1/4 yellow, 1/2 red+yellow, 1/4 red
incompletely dominant allele
