Chapter 2
GENETICS AND PRENATAL
DEVELOPMENT
Agree or Disagree?
Individual differences in violent or
antisocial behavior are heritable.
• I agree with this statement.
• I disagree with this statement.
Do You Know?
Many cultures have beliefs about how to
predict a baby’s sex.
What are some of the predictive beliefs
found in American culture or
subcultures?
Agree or Disagree?
Children can influence the effects of their
environments by seeking out niches that
correspond to their genotypic
characteristics.
A.I agree with this statement.
B.I disagree with this statement.
Agree or Disagree?
Life begins when a neonate takes his or her
first breath.
A.I agree with this statement.
B.I disagree with this statement.
• Strategies
– The old fashioned way
– In vitro
– Surrogate
– Artificial insemination
• Following ovulation, fertilization occurs in
fallopian tube
• Cell division occurs in the zygote
• Flows into uterus
• Germinal Stage
– Fertilized egg not yet implanted in the uterus
– Upon initial cell division the fertilized egg
becomes a zygote
– At approximately 12 days following
fertilization, zygote is implanted in the lining
of the uterus
– Cells specialize into what will become organs
• Embryonic Stage
– Differentiation of tissues into what will become organs
(organogenesis)
– Movements to stimuli based on “hard-wired” reflexes;
– Critical period of pregnancy in that as organogenesis
occurs, anomalies can result in miscarriage
– Umbilical cord and placenta develop and provide
nutrition and oxygen to and remove waste from the
embryo
– Developmental patterns:
• Cephalocaudal Patterns
• Proximodistal Patterns
• Fetal Period
– Begins approximately 8 weeks post fertilization
– Organogenesis is complete
– At approximately 3 months, genitalia can be
identified
– At approximately 4 months, movements can be felt by
the mother
– At approximately 7 months fetus may be “viable”
(can survive outside the womb with nutrition and
temperature regulation support).
• Growth: brain cells develop from the neural tube
across the prenatal period and into infancy
• Migration: brain cells migrate or move from the
center of the developing brain to the periphery
• Elaboration:
– connections among the axons and dendrites of
the cells are based on genetics during the
prenatal period;
– postnatal experience (nurture) enhances and
inhibits elaboration (e.g. first 6 months of life
the infant is particularly “wired” to learn
sounds of language)
• Teratogens: Toxins that impact the developing
organism prenatally
– Nicotine—increased heart rate; low birth weight
– Alcohol—fetal alcohol syndrome (mental retardation,
physical abnormalities)
– Rubella (German measles)—can be transmitted from
pregnant mother to fetus; can result in blindness,
other physical problems, and death
– HIV—without medication can be transmitted from
pregnant mother to fetus
– Psychoactive drugs—multiple effects
• Maternal Anxiety and Stress during late
pregnancy related to:
– Attentional problems
– Reactions to novelty
• Maternal Age (extremely young and
older)
• STD’s
– Herpes
– HIV/AIDS
– Syphilus
• Points at which key transitions occur tend
to be the most critical
– Attachment to the uterine wall
– Organogenesis tends to most vulnerable to
major “malformations.” (Germinal Stage)
– Chronic exposure to toxins during fetal stage
linked to delay in fetal growth and deficits in
intellectual potential (fetal stage)
• Health of Sperm—toxins, radiation, drugs and
alcohol
• Supportive partner—emotional support, support
for alcohol & tobacco free pregnancy
• Support and encourage access to health care
• Maternal comfort and safety is most
important in selecting birthing option
• Pregnancy complications can limit safe
options
• Prenatal health
– Emotional support
– Nutrition
– Exercise
– Prenatal health care
• Apgar (1 minute & 5 minutes; Scores: 0, 1, or
2)
– Heart rate.
– Skin color.
– Muscle tone (judged by whether the newborn's
arms and legs are flexed or limp).
– Breathing, or respiratory effort
– Reflex irritability (judged by whether the
newborn cries or reacts when the skin is stroked
or touched).
• Can earn a total score of 10…most don’t get it
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Phenylketonuria (PKU) test for neonates
Hearing
Antibiotic eyedrops
Vitamin Injections
Early breast feeding provides antibodies
Caring, supportive, safe, and healthy
environment
L.O. 2.10
True or False?
In most of the world the survival rate is
about 50 percent before 26 weeks.
• True
• False
L.O. 2.11
Do You Know?
All cultures have a store of advice about
what a woman should and should not
do during pregnancy.
Do you know one helpful method of
prenatal care common to developing
and developed cultures?
L.O. 2.13
True or False?
Chromosomal problems occur not because
the parents have an inherited problem
that they pass on to their children, but
usually because of the age of the parents.
• True
• False