1. Review the Brief Chapter Summary.
2. Answer and submit the Learning Objectives. Write the question and then the answer.
3. Complete and submit the Learning Activity. Write the question and then the answer.
1354 CHAPTER 2 MODULE 2: Chapter 2 Biological and Environmental Foundations
BRIEF CHAPTER SUMMARY
This chapter examines the foundations of development: heredity and environment. The principles of genetic
transmission determine the characteristics that make us human and contribute to individual differences in appearance
and behavior. Inheritance of harmful recessive genes and abnormalities of the chromosomes are major causes of
serious developmental problems. Genetic counseling and prenatal diagnosis help people at risk for transmitting
hereditary disorders assess their chances of giving birth to a healthy baby.
Environmental influences on development are no less complex than hereditary factors. The family has an
especially powerful impact. It operates as a complex, dynamic social system in which members exert direct, indirect,
and third-party effects on one another. Socioeconomic status influences child-rearing practices: Poverty and
homelessness undermine effective family functioning and childrenÕs well-being, while affluence may lead to
overscheduling and lack of emotional closeness, which also have negative effects. The quality of community life,
from neighborhoods and schools to small towns and cities, is another influence on childrenÕs development. Cultural
valuesÑfor example, the degree to which a society emphasizes collectivism versus individualismÑcombine with
public policies, laws, and government programs to shape experiences in all of these contexts.
Some child development specialists believe that it is useful and possible to determine Òhow muchÓ heredity and
environment contribute to individual differences. Others think that the effects of heredity and environment cannot be
clearly separated. Instead, they want to discover ÒhowÓ these two major determinants of development work together
in a complex, dynamic interplay.
LEARNING OBJECTIVES
After reading this chapter, you should be able to:
2.1 Distinguish between genotypes and phenotypes. (p. 51)
2.2 Describe the structure and function of chromosomes and DNA molecules. (p. 52)
2.3 Explain the process of mitosis. (pp. 52-53)
2.4 Describe the process of meiosis, and explain how it leads to genetic variability. (pp. 53-54)
2.5 Describe the genetic events that determine the sex of the new organism. (pp. 54-55)
2.6 Identify two types of twins, and explain how each is created. (pp. 55-56)
2.7 Explain how alleles influence the inheritance of traits, such as through dominantÐrecessive inheritance,
incomplete dominance, X-linked inheritance, polygenic inheritance, mutation, and genetic imprinting. (pp. 56-60)
2.8 Describe the origins and consequences of Down syndrome and abnormalities of the sex chromosomes. (pp. 60-62)
2.9 Discuss reproductive choices available to prospective parents, noting the pros and cons of reproductive
technologies. (pp. 63-68)
2.10 Describe family functioning from the ecological systems perspective, citing direct and indirect family
influences and explaining the view of the family as a dynamic, changing system. (pp. 69-71)
2.11 Discuss the impact of socioeconomic status, including affluence and poverty, on family functioning. (pp. 71-75)
2.12 Summarize the role of neighborhoods and schools in the lives of children. (pp. 75-77)
2.13 Discuss how cultural values and public policies influence the well-being of children. (pp. 77-82)
2.14 Explain the various ways heredity and environment may combine to influence complex human traits. (pp. 82-89)
LEARNING ACTIVITY 2.4: More on The Human Genome Project (pp. 64Ð66)
The Human Genome Project has identified thousands of genes, including those involved in hundreds of diseases. To
extend the text discussion of the Human Genome Project, visit the website http://www.ornl.gov/sci/
techresources/Human_Genome/home.shtml, which provides current research, progress in DNA sequence mapping,
and ethical, legal, and social concerns.
1. What are the benefits of the Human Genome Project?
2. What are some ethical and legal concerns? How do you feel about genetic research?