Question

What is a common misconception in genetics, especially at the high-school level?

a. All genes follow a codominant inheritance pattern
b. Phenotypes are determined by environmental factors only
c. Ascertainment bias is irrelevant in genetics
d. All genes exhibit a classic Mendelian dominance/recessive relationship

Which genetic models often perform well, assuming linearity and additivity?
a. Dominance models
b. Co-dominance models
c. Quantitative genetics models
d. Epistatic genetics models

What is a potential reason for our fixation on dominance in genetics?
a. Ascertainment bias inherited from Mendel
b. Lack of understanding of genetic concepts
c. Complexity of additive models
d. Overemphasis on codominance

In the study by Okbay et al. (2022), what did they find regarding dominance GWAS for educational attainment?
a. Dominance alleles explain a significant fraction of the variance
b. No genome-wide significant SNPs in dominance GWAS
c. A high number of dominant alleles governing the phenotype
d. Dominance deviations significantly explain variance in EA

What do studies on genetic variance components suggest about the contribution of dominance variance to complex traits?
a. Dominance variance often accounts for a significant portion
b. Dominance variance is negligible for most complex traits
c. Dominance variance exceeds additive variance
d. Dominance variance is consistent across all phenotypes

Why might there be a biological bias for additivity in genetic traits?
a. Additive mutations require simultaneous occurrences
b. Dominant mutations are more likely to be beneficial
c. Polygenicity itself contributes to additive variance
d. Mutations leading to additivity are random and unpredictable

Answer 1

Mendel studied traits with dominant and recessive alleles, but there are exceptions to this pattern such as incomplete dominance and codominance.

Step-by-step explanation:

Mendel studied traits with only one mode of inheritance in pea plants. The inheritance of the traits he studied all followed the relatively simple pattern of dominant and recessive alleles for a single characteristic. However, alleles do not always behave in dominant and recessive patterns. There are exceptions to Mendel's model of inheritance, such as incomplete dominance and codominance. Incomplete dominance occurs when the heterozygote exhibits a phenotype that is intermediate between the homozygous phenotypes, while codominance involves the simultaneous expression of both alleles in the heterozygote.