2. When alleles are not completely dominant or recessive
3. When a particular gene has more than 2 alleles
Most genes have multiple phenotypic effects. This is called?
What is it called when phenotypes of the heterozygote and the dominant homozygote are identical?
What it is called when the phenotype of the F1 hybrids is somewhere between the phenotype of the 2 parental varieties?
True or False: Dominant alleles are always more common in population than recessive alleles.
What is codominance?
Two alleles both affect the phenotype in separate, distinguishable ways
Phenotype depends on _______ and ________.
environment and genotype
What is epistasis?
The alleles of one gene mask the expression of the alleles of another gene. It was discovered by Bateson and Punnett in the early 1900's when studying sweet peas
Traits that are "either or"traits are referred to as what?
Traits that vary in a population along a continuum creating a bell shaped curve are called what?
Who was the first scientist to associate a specific gene with a specific chromosome?
Thomas Hunt Morgan
A normal character phenotype is referred to as what?
What 3 ideas did Morgan propose?
1. Genes are said to be linked and are inherited together as a unit called a linkage group
2. Due to crossing over during meiosis, homologous chromosomes can exchange pieces of chromosomes and create new combinations of alleles
3. The likely hood of a crossover occurring in the region between two genes depends on the distance between two genes
Map distance =
number of recombinants
------------------------------------ x 100
total number of offspring
True or False: The farther apart two genes are, the higher the probability that a cross will occur.
What is it called when some inheritance patterns do not conform to the law of segregation and when some genes are not found on the same chromosomes in the cell nucleus and do not segregate the same way
What is the maternal effect?
The genotype of the mother determines the phenotype of the offspring