Environment and Plasticity

These flashcards cover the key concepts related to environment, genetic variation, phenotype, genotype, and heritability from the lecture notes.

What is the difference between phenotype and genotype?

Phenotype refers to the characters of an individual organism, while genotype is the genetic constitution of that organism.

What is phenotypic plasticity?

Phenotypic plasticity is the capacity of an organism to express different phenotypes in different environments.

Define Norm of Reaction.

Norm of Reaction refers to the variety of different phenotypes that can be produced by a single genotype under different environmental conditions.

Give an example of a model organism that shows genotype x environment interaction.

Drosophila abdominal bristles show genotype x environment interaction.

What does the formula h2 = VG/(VG + VE) represent?

This formula calculates the proportion of total variance that is heritable.

What are non-genetic effects on phenotypes, and provide an example?

Non-genetic effects are influences that affect phenotypes but are not caused by genotype, such as maternal effects like temperature and nutrition.

What is epigenetic inheritance?

Epigenetic inheritance refers to inherited phenotypic differences that are not based on DNA sequences.

How is heritability of quantitative traits estimated using variance?

Heritability is estimated by partitioning total variance into genetic variance (VG) and environmental variance (VE) and calculating h2.

What is the significance of the midparent/offspring correlation in heritability studies?

The midparent/offspring correlation (R2) is used to estimate heritability (h2); a correlation close to 1 indicates high heritability.

What was the heritability estimate computed by Dobzhanski for phototaxis in fruit flies?

The heritability estimate for phototaxis in fruit flies computed by Dobzhanski was 0.09.