Question

Suppose a study is being conducted to understand the potential heritability of artistic ability. Specifically, the study wants to recruit pairs of monozygotic and dizygotic twins raised in the same or in different environments. For each scenario, what is the theoretical genetic variance and environmental variance?
1. Monozygotic in the same environment
2. Monozygotic in a different environment
3. Dizygotic in the same environment
4. Dizygotic in a different environment
Answer Bank
0% genetic variance, 100% environmental variance
0% genetic variance, 0% environmental variance
50% genetic variance, 100% environmental variance
50% genetic variance, 0% environmental variance
Using the data collected from the study, what equation could be used to estimate the degree of phenotypic variability of artistic ability that is due to genetic factors?
H² = 2(rmz-rpz), where H² is broad-sense heritability
h2 VA/VP, where h’ is narrow-sense heritability
h2 = 2b, where ha is narrow-sense heritability
Vp = VA + VD + V1 + VE + VGE, where Vp is phenotypic variance

Answer 1

Answer:

Explanation:

Monozygotic in the same environment

Genetic Variance will be zero and the environmental variance will be zero this is because a monozygotic twin shares the same gene 100% and because they stay in the same environment they are equally exposed to the same thing this makes environmental variance Zero.

Monozygotic in a different environment

Monozygotic in different environment will have an environmental variance 100% this is because they are expose to different environment leading to variation in what they know and 0% genetic variance

Dizygotic in the same environment

They have 0% environmental variation and 50% genetic variation this is because they are fraternal twins and not 100% genetically only 50% of their traits are identical

Dizygotic in a different environment

They will have 100% environmental variance because they are raised in different envrionment leading to variation in idea and what they know and 50% genetic variance because Dizygotic twin are not genetically identical.

The formula to calculate phenotypic variance due to genetic variation is

Hb2 = 2(rmz - rdz) this is in accordance to falconer's formula for twin heritability and its estimatebroad sense heritage.

Where hb2 is broad sense heritability