Transcript File

CHAPTER 2
GENETIC AND
ENVIRONMENTAL FOUNDATIONS
LEARNING OUTCOMES
• Define genes and how they are transmitted from one generation
to the next
• Describe genetic inheritance
• Identify Reproductive choices
• Describe environmental contexts for development
• Understand the relationship between heredity and environment
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KEY WORDS
• DEFINE EACH
• CHROMOSOME
• DNA
• MITOSIS
• GAMETES
• MEIOSIS
• ZYGOTE
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Genetic Foundations
Chromosomes
Rodlike structures within the
cells that store and transmit
genetic information
DNA
Deoxyribonucleic acid, the chemical
substance that makes up
chromosomes
Gene
Segment of DNA along the
length of the chromosome
Differences Between
Mitosis and Meiosis
Mitosis
 Process by which
DNA duplicates
itself
 Produces new
body cells
containing the
same genetic
information
Meiosis
 Process by which
gametes (sex cells)
are formed
 Halves the number
of chromosomes
normally present
 Leads to genetic
variability
MITOSIS AND MEIOSIS
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QUESTIONS
• TRUE OR FALSE THE FEMALE IS BORN WITH A BANK OF OVA ALREADY
PRESENT IN HER OVARIES
• WHAT ABOUT MALES?
• X CHROMOSOME IS LARGER OR SMALLER THAN Y CHROMOSOME
• XX IS __________
• XY IS __________
• SEE PAGE 37 FOR ANSWER
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CHROMOSOMES, GENES,
AND DNA
Copyright © 2015 McGraw-Hill Education. All rights reserved.
No reproduction or distribution without the prior written consent of McGraw-Hill
Education.
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Define genes and how they are transmitted
from one generation to the next
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Autosomes, Sex
Chromosomes, and Sex Cells
Autosomes
22 matching pairs
of chromosomes
Sex
chromosomes
23rd pair of chromosomes
(XX = female, XY = male)
Gametes
Sex cells: sperm and ovum
Zygote
Formed when sperm
and ovum unite
Genotype and Phenotype
Genotype
An individual’s
genetic
information
Phenotype
An individual’s
directly
observable
characteristics
© szefei/Fotolia
Twins
Fraternal/Dizygotic
Result from release
and fertilization of two
ova
Identical/Monozygotic
Result when a single
zygote separates
to form two
individuals
© Blend Images/Shutterstock
Alleles
 Two forms of the same gene, one
inherited from each parent
 homozygous (both alleles are alike)
 heterozygous (alleles differ)
 Occur at the same place on both
chromosomes in a pair
Resources:
http://learn.genetics.utah.edu/content/inheritanc
e/observable/
CARD GAME – OBSERVATION OF TRAITS
Dominant–Recessive
Inheritance
 Only the dominant allele affects
children’s phenotypic characteristics
 Carriers:
 heterozygous (have one recessive allele)
 can pass recessive trait to their children
 Many serious diseases are product of
recessive alleles
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Incomplete Dominance
 Both alleles are expressed in the phenotype
 Possible results:
 combined trait
 trait that is intermediate between
the two
 Example: sickle cell anemia
X-Linked Inheritance
Figure 2.4
Genomic Imprinting, Mutation,
and Polygenic Inheritance
 Genomic imprinting:
 chemical marker activates one allele in a pair
 often temporary; may not occur in all individuals
 Mutation:
 sudden, permanent change in a segment of DNA
 may affect one or two genes, or many
 Polygenic inheritance:
 characteristics influenced by many genes
Chromosomal Abnormalities
 Down syndrome: caused by problems
with 21st chromosome
 Sex chromosome abnormalities:
 caused by problems
with X or Y
chromosome
 often not recognized
until adolescence
© Denis Kuvaev/Shutterstock
Prenatal Diagnostic Methods
See page 44
 Amniocentesis
 Chorionic villus
sampling
 Fetoscopy
 Ultrasound
 Maternal blood analysis
 Ultrafast magnetic resonance imaging
 Preimplantation genetic diagnosis
© PhotographyByMK/Shutterstock
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Genetic Counseling
 Helps couples
 assess chances of hereditary disorders
 choose best course of action in view of risks
and family goals
 Recommended when
 couple has had difficulties bearing children
 known genetic problems exist
 woman is over 35
Reproductive Choices
© Monkey Business Images/Shutterstock
 Genetic
counseling
 Prenatal diagnosis
and fetal medicine
 Reproductive
technologies
 Adoption
Reproductive Technologies
 Donor insemination
 In vitro fertilization
 Surrogate
motherhood
 New technologies
© Burlingham/Shutterstock
VIDEO ON REPRODUCTIVE
TECHNOLOGY
• http://abavtooldev.pearsoncmg.com/VPsms/simpleviewer.php?projectID
=BerkICA7&clipID=004_ReproductiveTechnology.flv&ui=2
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Adoption
 Trends:
 international adoption
 adoption of older children
 adoption of children with
known developmental
problems
© Vitalinka/Shutterstock
 Children typically exhibit some difficulties,
but most fare well
Environmental Contexts
for Development
 Family
 Socioeconomic
status and
family functioning
 Neighborhoods,
towns, and cities
 Cultural context
© Mat Hayward/Fotolia
Family Influences
on Development
© auremar/Fotolia
 Direct influences
 Indirect influences:
effects of third
parties
 Adaptation to
changes within
and outside
the family
Socioeconomic Status (SES)
 Social status:
 years of education
 prestige of one’s job
and skill it requires
 Economic status:
income
© Yanming Zhang/Shutterstock
Socioeconomic Status
and Family Functioning
SES is linked to:
timing of marriage and parenthood
family size
values and expectations for children
parents’ education and economic security
communication and discipline styles
investment in children’s cognitive development
Poverty
Who Is Poor?
 46 million Americans (15%) are poor
 Those hit hardest are:
 parents under age 25 with young children,
especially single mothers
 older adults who live alone,
especially women
 children, especially AfricanAmerican, Native-American,
© gcelebi/Shutterstock
and Hispanic children
Indicators of Children’s
Health and Well-Being
Table 2.3
(Sources: Canada Campaign 2000, 2009; OECD 2010; U.S. Census Bureau, 2012; U.S. Department of Education, 2012.)
Percentage of
Older Adults
Living in
Poverty
Figure 2.5
(Adapted from Luxembourg Income Study, 2011.)
KERN COUNTY POVERTY
• http://www.countyhealthrankings.org/
• http://kern.org/kcnc/wpcontent/uploads/sites/43/2015/06/2015ReportCard_interactive.pdf
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Affluence
What Are the Risks of Affluence?
 Alcohol and drug use
 High levels of anxiety
and depression
 Unavailable parents:
© Beata Wawrzyniuk/Shutterstock
 lack of emotional
closeness and
supervision
 excessive demands
for achievement
Gene–Environment Interaction
 Individuals respond differently to same
environment because of genetic makeup
 Similar responses can result from different
gene–environment combinations
© atikinka/Shutterstock
AVERAGE RISK OF SCHIZOPHRENIA
THE AVERAGE RISK OF SCHIZOPHRENIA STEADILY INCREASES IN DIRECT
RELATION TO THE CLOSENESS OF ONE'S BIOLOGICAL RELATIONSHIP TO AN
INDIVIDUAL WITH THE DISORDER.
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Gene–Environment Correlation
Page 55
 Passive correlation
 Evocative correlation
 Active correlation: niche-picking
© szefei/Shutterstock
Epigenesis
Development results from bidirectional
exchanges between heredity and all
levels of environment
 Genes affect behavior and experiences
 Experiences and behavior affect gene
expression
THE EPIGENETIC FRAMEWORK
Figure 2.7
(Adapted from Gottlieb, 2007.)
teratogenic effect
• teratogenic effect
• http://medical-dictionary.thefreedictionary.com/teratogenic+effect
• https://www.purdue.edu/ehps/rem/ih/terat.htm
• Look at Page 57 –
• What are your Thoughts,
• Do you think People in Kern County understand how their Environment and behaviors
can Impact their Child’s well Being?
• What do you think would resonate or Get someone's attention?
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KERN COUNTY REFLECTION
• KERN COUNTY ENVIRONMENT
• SMOKING EXAMPLE
• BIOLOGY AND ENVIORNMENT
• READ PAGE 57
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REVIEW LEARNING OUTCOMES
• Define genes and how they are transmitted from one generation
to the next
• Describe genetic inheritance
• Identify Reproductive choices
• Describe environmental contexts for development
• Understand the relationship between heredity and environment
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