In their study of the heritability of autistic traits among Dutch teens, Rosa Hoekstra and her colleagues were careful to choose participants from a variety of backgrounds and circumstances. Why is careful sampling especially important to studies of heritability?
a. The effects of heritability are most obvious in populations that exclude extreme environmental conditions, such as affluent or very poor families.
b. Environmental influences are magnified in extreme environmental conditions, such as among affluent or very poor families.
c. Extremes of environmental conditions, such as affluent or very poor families, tend to magnify the influence of heritability.
d. These precautions are really not relevant, because heritability cannot be assessed experimentally.
Question 2
What causes muscles to twitch?
a. depolarization of the muscle fiber produced by an influx of sodium ions
b. depolarization of the muscle fiber produced by an influx of potassium ions
c. hyperpolarization of the muscle fiber produced by an influx of calcium ions
d. hyperpolarization of the muscle fiber produced by an outflow of potassium ions
Dutch Smoushond
Study of human diseases
Estimates of Heritability for Traits in Different Organisms part 2
Frequency of Heterozygotes for Some Recessive Traits in Several Populations
Study Tips
Threshold traits