BIOL 102 Chapter 2 Study guide latest 2020 - Liberty University
Chapter 2
The Start of Life: Genetics and
Prenatal Development
CHAPTER OUTLINE
Earliest Development
Genes and Chromosomes: The Code of Life
The B
...
BIOL 102 Chapter 2 Study guide latest 2020 - Liberty University
Chapter 2
The Start of Life: Genetics and
Prenatal Development
CHAPTER OUTLINE
Earliest Development
Genes and Chromosomes: The Code of Life
The Basics of Genetics: The Mixing and Matching of Traits
Transmission of Genetic Information
The Human Genome and Behavioral Genetics: Cracking the Code
Inherited and Genetic Disorders: When Development Deviates from the Norm
Genetic Counseling: Predicting the Future from the Genes of the Present
The Interaction of Heredity and Environment
The Role of the Environment in Determining the Expression of Genes: From Genotypes to Phenotypes
Studying Development: How Much Is Nature? How Much Is Nurture?
Physical Traits: Family Resemblances
Intelligence: More Research, More Controversy
Genetic and Environmental Influences on Personality: Born to Be Outgoing?
Psychological Disorders: The Role of Genetics and Environment
Can Genes Influence Environment?
Prenatal Growth and Change
Fertilization: The Moment of Conception
The Stages of the Prenatal Period: The Onset of Development
Pregnancy Problems
The Prenatal Environment: Threats to Development
LEARNING OBJECTIVES
After you have read and studied this chapter, you should be able to answer the following questions.
1. What is our basic genetic endowment, and how can human development go off track?
2. How do the environment and genetics work together to determine human characteristics?
3. Which human characteristics are significantly influenced by heredity?
4. What happens during the prenatal stages of development?
5. What are the threats to the fetal environment and what can be done about them?20
PRACTICE TEST – PRETEST
Circle the correct answer for each of the following multiple choice questions and check your answers with the
Answer Key at the end of this chapter.
1. Michelle is expecting twins that are the result of two eggs being fertilized by two sperm. Her babies are
a. dizygotic. c. monozygotic.
b. identical. d. multizygotic.
2. Becky's mother has blue eyes and her father has brown eyes. Becky has brown eyes. Becky's phenotype is
a. blue eyes.
b. brown eyes.
c. two "brown eye" genes.
d. one "brown eye" gene and one "blue eye" gene.
3. Which of the following is a genetically normal male?
a. XY c. YX
b. XX d. YY
4. A person with Down syndrome has
a. only one chromosome 5. c. an extra chromosome 21.
b. an extra X chromosome. d. two X and one Y chromosome.
5. At about the seventh week of pregnancy, a test was done on a patient that involved withdrawing and analyzing
amniotic fluid. This test is called
a. fetoscopy. c. amniocentesis.
b. ultrasound. d. chorionic villus sampling.
6. Infertility is defined as the inability to conceive after
a. 3 to 6 months of sexual intercourse.
b. 10 months of sexual intercourse.
c. 12 to 18 months of trying to get pregnant with unprotected intercourse.
d. 24 months of trying to get pregnant with the help of fertility drugs.
7. _____ usually causes death before its victims reach school age and occurs mainly in Jews of eastern European
ancestry and in French-Canadians.
a. Sickle-cell anemia c. Klinefelter’s syndrome
b. Tay-Sachs disease d. Fragile X syndrome
8. What difference in temperament did Kagan find in his study that compared 4-month-old infants in China,
Ireland, and the United States?
a. Chinese babies had significantly lower motor activity, irritability, and vocalization.
b. American babies had abnormally high motor activity, irritability, and vocalization.
c. American babies had significantly lower motor activity, irritability, and vocalization.
d. Irish babies had significantly lower motor activity, irritability, and vocalization.
9. What is the first stage of prenatal development?
a. zygotic c. germinal
b. embryonic d. blastocyst
10. A patient took DES during pregnancy. Her daughter has a possible risk of
a. sterility. c. breast cancer.
b. toxemia. d. vaginal or cervical cancer.21
11. The process by which a sperm and an ovum join to form a single new cell is called
a. ovulation. c. fertilization.
b. conception. d. insemination.
12. When couples use fertility drugs to help them conceive, what is the chance that they will have dizygotic
twins?
a. 1 in 10 c. 1 in 100
b. 1 in 50 d. 1 in 1000
13. Polygenic inheritance is
a. the phenotype of the individual.
b. a trait that is expressed in the individual, but not inherited.
c. a trait caused by an interaction of gene pairs.
d. one gene of a gene pair causing a particular trait to be expressed.
14. The gender of the child is determined by
a. the mother.
b. the father.
c. random distribution of chromosomes.
d. the mother for a girl and the father for a boy.
15. Which of the following is an inherited disorder produced by a single allele?
a. FAS c. PKU
b. CVS d. FAE
16. Which of the following disorders does NOT result in some degree of mental retardation?
a. Down syndrome c. Klinefelter’s syndrome
b. Tay-Sachs disease d. Fragile X syndrome
17. Basic units of genetic information are
a. gametes. c. chromosomes.
b. DNA. d. genes.
18. The determination of traits by a combination of both genetic and environmental factors is
a. polygenic transmission. c. chorionic transmission.
b. dizygotic transmission. d. multifactorial transmission.
19. _____ studied cross-pollination of pea plants to observe properties of dominant and recessive traits.
a. Darwin c. Jensen
b. Mendel d. Scarr
20. The conduit between the mother and fetus is the
a. blastocyst. c. placenta.
b. endoderm. d. amnion.
KEY NAMES
Match the following names with the appropriate description.
1. ___ Arthur Jensen a. dominant and recessive traits
2. ___ Jerome Kagan b. genotype-environment effects
3. ___ Gregor Mendel c. inheritance of intelligence22
4. ___ Sandra Scarr d. temperament
KEY VOCABULARY TERMS
Explain the difference between the terms in each of the following groups.
1. Monozygotic twins; Dizygotic twins
2. Homozygous; Heterozygous
3. Dominant trait; Recessive trait
4. Fetal alcohol syndrome (FAS); Fetal alcohol effect (FAE)
5. Genes; DNA; Chromosomes
6. Down syndrome; Sickle-cell anemia
Look up the definitions of the following terms and given a specific example of each.
7. Polygenic inheritance 10. Multifactorial transmission
8. Behavioral genetics 11. Temperament
9. Genetic counseling 12. Teratogen
Explain the relationship among the following.
13. Gametes, Fertilization, Zygote, Germinal stage, Embryonic stage, Fetal stage, Fetus
Differentiate among the following prenatal tests.
14. Amniocentesis; Chorionic villus sampling (CVS); Ultrasound sonography
Differentiate among the following methods of fertilization.
15. Artificial insemination; In vitro fertilization (IVF); Surrogate mother
Fill in the blanks in each of the following puzzles with the term that belongs with each definition. The first
letter of each term will spell, from top to bottom, the term that matches the last definition. (NOTE: Some
terms may be from previous chapters.)
16. _ A disorder produced by injury to a gene on the 23rd
chromosome pair, producing mild to moderate mental
retardation is called Fragile _ syndrome.
_ _ _ _ _ _ _ _ _ _ _ _ Research in which behaviors of one or more participants
in a study are measured as they age.
_ _ _ _ _ _ _ _ _ _ _ The inability to conceive after 12 to 18 months of trying
to become pregnant.
_ _ _ _ _ _ _ _ _ _ _ _ A type of observation in which naturally occurring
behavior is observed without intervention.
-
-
-
-
-
-
-
PRACTICE TEST – POST TEST
Circle the correct answer for each of the following multiple choice questions and check your answers with the
Answer Key at the end of this chapter.
1. Your hair color is your
a. gene. c. phenotype.
b. genotype. d. heredity.
2. If Jamie has blue eyes, her mother has blue eyes, and her father has brown eyes, Jamie is
a. cross-modal. c. heterozygous.
b. homozygous. d. multidimensional.
3. Bryan is an African American with the following symptoms: yellowish eyes, poor appetite, stunted growth,
and a swollen stomach. He may have
a. hemophilia. c. sickle-cell anemia.
b. Tay-Sachs disease. d. Klinefelter's syndrome.
4. A man is extremely tall, has small external male sex organs, and breast enlargement. What genetic disorder
does he have?
a. Down syndrome c. Sickle-cell anemia
b. Tay-Sachs disease d. Klinefelter's syndrome
5. Which of the following statements is true regarding a father’s effect on the prenatal environment?
a. Father’s drug use and physical or emotional abuse of the mother can adversely affect the unborn child.
b. Father’s drug use can benefit the unborn child.
c. Father’s physical abuse of the mother can positively affect the unborn child.
d. Fathers have no effect on the prenatal environment.
6. A couple having trouble getting pregnant went to an infertility specialist. The doctor shared with them that
they were not alone in their difficulty conceiving, and that ______ % of couples meet the criteria of infertility.
a. 5% c. 15%
b. 10% d. 20%
7. A patient of yours has schizophrenia. Her monozygotic twin has what chance of developing schizophrenia?
a. 50% c. 80%
b. 60% d. 95%
8. You notice that a child demands responses from her parents and babysitter. How would you describe this
child's interaction with the environment?
a. active c. prosocial
b. passive d. evocative
9. A pregnant woman works around toxic fumes and her baby is born with birth defects. It is possible that the
toxic chemical acted as a
a. virus. c. teratogen.
b. bacteria. d. pathogen.
10. You have a patient who admits to drinking several alcoholic beverages a day during her pregnancy. You will
need to monitor her child for
a. Down syndrome. c. Klinefelter's syndrome.
b. FAS. d. diethylstilbestrol (DES).31
11. When a cell duplicates itself exactly, the process is called
a. mitosis. c. fertilization.
b. meiosis. d. homozygotic.
12. Although Ashanti has a headache she decides not to take an aspirin during her pregnancy. Her decision is
a. unwise, there are no risks associated with taking legal drugs during pregnancy.
b. unwise, aspirin has no effect on a fetus during prenatal development.
c. wise, the use of aspirin may cause fetal bleeding or growth impairments.
d. wise, pregnant mothers should avoid all artificial substances during pregnancy.
13. A prenatal diagnostic procedure which involves high-frequency sound waves that form a picture of a fetus is
called
a. fetoscopy. c. ultrasound sonography.
b. amniocentesis. d. chorionic villus sampling.
14. Who studied the role of genes in intelligence?
a. Darwin c. Mendel
b. Kagan d. Jensen
15. What percent of the gene sequence is shared by all humans?
a. 25.3 c. 66.5
b. 43.8 d. 99.9
16. A developing child is able to swallow and urinate. Its arms develop hands, hands develop fingers, and fingers
develop nails. What stage of prenatal development is the child experiencing?
a. germinal c. embryonic
b. zygotic d. fetal
17. DNA tests are available for all of the following disorders EXCEPT
a. cystic fibrosis. c. hemophilia.
b. diabetes. d. retinoblastoma.
18. At the end of the _____ stage the developing human has rudimentary eyes, nose, and lips, although what
appear to be gills and a tail-like structure may make it look nonhuman.
a. conception c. embryonic
b. germinal d. fetal
19. A physician places a man’s sperm directly into a woman’s vagina in
a. CVS. c. artificial insemination.
b. IVF. d. surrogate motherhood.
20. Which of the following is transmitted to the child as it passes through the birth canal?
a. rubella c. AIDS
b. syphilis d. gonorrhea
LEARNING OBJECTIVES REVISITED
1. What is our basic genetic endowment, and how can human development go off track?
• A child receives 23 chromosomes from each parent. These 46 chromosomes provide the genetic blueprint
that will guide cell activity for the rest of the individual’s life.
• Gregor Mendel discovered an important genetic mechanism that governs the interactions of dominant and
recessive genes and their expression in alleles. Traits such as hair and eye color and the presence of
phenylketonuria (PKU) are alleles and follow this pattern.32
• Genes may become physically damaged or may spontaneously mutate. If damaged genes are passed on to
the child, the result can be a genetic disorder.
• Behavioral genetics, which studies the genetic basis of human behavior, focuses on personality
characteristics and behaviors, and on psychological disorders such as schizophrenia. Researchers are now
discovering how to remedy certain genetic defects through gene therapy.
• Genetic counselors use data from tests and other sources to identify potential genetic abnormalities in
women and men who plan to have children. Recently, they have begun testing individuals for genetically
based disorders that may eventually appear in the individuals themselves.
2. How do the environment and genetics work together to determine human characteristics?
• Behavioral characteristics are often determined by a combination of genetics and environment. Genetically
based traits represent a potential, called the genotype, which may be affected by the environment and is
ultimately expressed in the phenotype.
• To work out the different influences of heredity and environment, researchers use nonhuman studies and
human studies, particularly of twins.
3. Which human characteristics are significantly influenced by heredity?
• Virtually all human traits, characteristics, and behaviors are the result of the combination and interaction
of nature and nurture. Many physical characteristics show strong genetic influences. Intelligence contains
a strong genetic component, but can be significantly influenced by environmental factors.
• Some personality traits, including neuroticism and extroversion, have been linked to genetic factors, and
even attitudes, values, and interests have a genetic component. Some personal behaviors may be
genetically influenced through the mediation of inherited personality traits.
• The interaction between genetic and environmental effects has been classified into three types: active
genotype–environment influences, passive genotype–environment influences, and evocative genotype–
environment influences.
4. What happens during the prenatal stages of development?
• The union of a sperm and ovum at the moment of fertilization, which begins the process of prenatal
development, can be difficult for some couples. Infertility, which occurs in some 15% of couples, can be
treated by drugs, surgery, artificial insemination, and in vitro fertilization.
• The germinal stage (fertilization to 2 weeks) is marked by rapid cell division and specialization, and the
attachment of the zygote to the wall of the uterus. During the embryonic stage (2 to 8 weeks), the
ectoderm, the mesoderm, and the endoderm begin to grow and specialize. The fetal stage (8 weeks to
birth) is characterized by a rapid increase in complexity and differentiation of the organs. The fetus
becomes active and most of its systems become operational.
5. What are the threats to the fetal environment, and what can be done about them?
• Factors in the mother that may affect the unborn child include diet, age, illnesses, and drug, alcohol, and
tobacco use. The behaviors of fathers and others in the environment may also affect the health and
development of the unborn child.33
ANSWER KEYS
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