Ch. 5 Extensions and Modification of Basic Principles Flashcards
If red is dominant and white is recessive and they are crossed, the offspring are pink
incomplete dominance
If red is dominant and white is recessive, and they are crossed, the offspring are red with white spots
codominance
Incomplete dominance phenotypic ratio of two heterozygotes
1:2:1
Individuals with the same genotype can have the phenotype or not have the phenotype
incomplete penetrance
Some people have the phenotype to a different degree (more vs less affected), but all are affected to some degree
variable expressivity
One of the genotypes will never be viable
lethal allele
When there are more than 2 alleles at a given locus
multiple alleles
True or False: blood type is an example of multiple alleles
True
This occurs when one gene masks the expression of another gene
epistasis
True or False: the hypostatic gene is the gene that may. be masked
True
True or False: the epistatic gene is the gene that does the masking
True
True or False: Epistasis is always a dihybrid
True
What is the phenotypic ratio for two complete heterozygotes in a dihybrid cross?
9:3:3:1
What is the phenotypic ratio for two complete heterozygotes in recessive epistasis?
9:3:4
What is the phenotypic ratio for two complete heterozygotes in dominant epistasis?
12:3:1
What is the phenotypic ration for two complete heterozygotes in duplicate recessive epistasis?
9:7
What traits are dominant in males and recessive in females (or vice versa)?
sex-influenced traits
What traits only appear. in females and never in males (or vice versa)?
sex-limited traits
True or False: sex-influenced traits are on the sex-chromosomes
False
True or False: sex-linked are on the sex chromosomes
True
True or False: sex-limited traits are on the sex chromosomes
False
The phenotype of the offspring is determined by the genotype of the mother
genetic maternal effect
True or False: if a trait follows the genetic maternal effect, the father can affect the physical appearance of his grandchildren
True
What type of allele is only expressed in certain temperatures
temperature-sensitive allele
