Questions: During gestation, a fetus's exposure to toxins, nutrients, and other stresses can turn off some genes and stimulate the expression of others. After birth, new positive and negative experiences further modify genetic expression and the activity of the nervous system. These represent components of: - heredity-environment correlation - behavioral genetics - the epigenetic view

The answer is the third one: the epigenetic view.

Explanation for each option:

1. Heredity-environment correlation: This concept refers to the idea that an individual's genes can influence the environment they are exposed to, and vice versa. However, it does not specifically address the modification of gene expression due to environmental factors during gestation and after birth.

2. Behavioral genetics: This field studies the role of genetic and environmental influences on behaviors. While it is related to the topic, it does not specifically focus on the changes in gene expression due to environmental factors.

3. The epigenetic view: This concept involves the study of how environmental factors can cause changes in gene expression without altering the DNA sequence. It specifically addresses how exposure to various factors during gestation and after birth can turn genes on or off, which aligns with the description provided in the question.

Summary: The correct answer is the epigenetic view, as it directly pertains to how environmental factors can influence gene expression during and after gestation.