Chapter 2 - E1 Flashcards
What is the idea of the blending theory of heredity?
Traits are presented as a mixture of the characteristics passed down from the parents
- Ex: red flower mother + white flower father = pink offspring
Pure/True Breeding individuals
Strains that consistently produce the same phenotype
- homozygous dom or recessive
What does the “F” in F1, F2, F3 stand for?
Filial generation
What is a reciprocal cross?
Where the donating sex is alternated to see if the trait is linked to a certain sex
What is a test cross?
Where you cross and individual with a dominant phenotype to a pure-breeding recessive individual to identify the genotype of the dom individual
What is the phenotypic ratio in the F2 generation of a monohybrid cross?
3:1, Dom:Recessive
What is particulate inheritance?
The idea that each plant carries two alleles for each trait
What is the genotypic ratio in the F2 generation of a monohybrid cross?
1:2:1 - Homo dom: hetero: homo recessive
What is the Law of Segregation?
Two alleles seperate during gamete formation
What is the genotype and phenotype of a dihybrid?
Heterozygous for both traits but display the dominany phenotype
In a cross between RrGg and RrGg, what are the gametes formed?
RG, rG, Rg, rg
What is the phenotypic ratio for a dihybrid cross?
9:3:3:1
Both dom: one trait dom: one trait dom: both recessive
What is a trihybrid cross?
Cross involving 3 traits
How many genotypes are there for AaBbCc?
2^n where n=heterozygous traits
2^3 = 8 genotypes
What is the phenotypic ratio of a trihybrid cross?
27:9:9:3:9:3:3:1
When do you use the product rule?
When 2 or more events are independent, multiply the probabilities if each were to occur
- Ex: What is the probabilty that 2 coins will both land on heads?
- – 1st coin: 1/2 —–2nd coin: 1/2 = 1/2 x 1/2 = 1/4
What is special about conditional probability?
Use both the product and sum rule
Applied to a specific outcome
- Ex: what is the probabilty that yellow plants are herozygous like the parents?
—–Do NOT consider any plant that is not yellow
What is the formula for a chi square analysis test?
Sum of (O-E)^2/E
Correlation between chi square and p-value?
High chi square value = low p value
How do you find the degrees of freedom?
n-1
n = the number of independent variables
What does it mean if the p value is significant? Not significant?
Hypothesis of chance is rejected
Fail to reject chance hypothesis
If individuals who are AaBBCcdd and AabbCcDd are crossed, what is the probability of having offspring with the genotype aaBbCcdd?
For A: 1/4 For B: 4/4 For C: 2/4 For D: 2/4 Multiply all these together = 16/256 = 1/16
Characteristic of Autosomal Dominant traits
2 unaffected parents will have no affected offspring
2 affected parents can have unaffected offspring
Characteristic of Autosomal Recessive traits
Parents with affected offspring are often unaffected
If both parents are affected, all children will be affected
