1. Chapter 3
Forming a New Life

2. Fertilization: conception, sperm meet ovum.
Zygote: single cell union of sperm and ovum
Girls: 2 million immature ovum in two ovaries at birth. Every 28 days is swept along fallopian tube by tiny cilia, toward the uterus or womb. Fertilization usually occurs during the 2-3 days when the ovum is passing through the fallopian tube.

3. Boys: sperm produced by testicles at a rate of about several hundred million per day and are ejaculated in the semen at orgasm. Sperm attempt to swim though cervix (opening of the uterus) and into fallopian tubes, but only a few make it. Pregnancy can occur up to five days after sperm enters vagina.

4. Figure 4.1 Life is sexually transmitted Myers: Psychology, Eighth Edition Copyright © 2007 by Worth Publishers

5. Multiple births
Dizygotic twins (fraternal twins): unfertilized egg splits and both are fertilized
Monozygotic twins (identical twins): single fertilized ovum splits into two. Temperament may differ, but most everything else the same.

6. Two Types of Multiple Births
Monozygotic (MZ)
One egg – One sperm
Identical Twins
Share 100% of genes
Dizygotic (DZ)
Two eggs – Two sperm
More common
Fraternal Twins
Share 50% of genes – just like non-twin siblings

7. Determination of Sex

8. Sex Determination Chromosomes: Coils of DNA carrying genes Autosomes:
22 pairs not related to sexual expression
Sex chromosomes:
1 pair determining sex
XX = female
XY = male

9. DNA: deoxyribonucleic acid: double-helix containing genetic code.
Chromosomes are coils of DNA that contain segments called genes (units of heredity)
23 pairs of chromosomes from each parent. Each sex cell ends up with 23 chromosomes (meiosis)
though mitosis, the nonsex cells continue to divide and replicate so that every cell has same DNA.

10. The Collaborative Gene
Genetic Foundations
The Collaborative Gene
Genes and chromosomes
Mitosis — cell nucleus duplicates
Meiosis — cell division forms gametes
Fertilization — egg and sperm form zygote
Genetic variability in the population
X and Y chromosomes determine sex

12. Cells, Chromosomes, Genes, and DNA
Genetic Foundations
Cells, Chromosomes, Genes, and DNA
Nucleus (center of cell) contains chromosomes and genes
Gene: a segment of DNA (spiraled double chain) containing the hereditary code
Chromosomes are threadlike structures composed of DNA molecules
Fig. 2.3

13. 22 pairs of chromosomes are not related to sex (autosomes).
The 23rd pair are sex chromosomes: all ovum chromosomes are x, but sperm may have the x or y chromosome. The y is for males (XY) and the x for females (XX).
Dominant inheritance: when heterozygous, dominant trait governs.
Recessive inheritance: expression of a recessive trait, occurs when received two recessive alleles, one from each parent.

14. Polygenetic inheritance: pattern of inheritance in which multiple genes at different sites on chromosomes affect a complex trait
Multifactorial transmission: comb of genetics and environmental factors produce certain complex traits
Phenotype: observable characteristics of a person
one from each parent.

15. Father B b Mother B b B B B b B b b b
Genetic Foundations
How brown-haired parents can have a blond-haired child: the gene for blond hair is recessive B
Brown hair
Blond hair b
Father
B b
Mother
B b
B B
B b
B b
b b

16. Genotype: genetic make-up of a person, containing both expressed and unexpressed characteristics
Defects: both parents give recessive gene for the abnormality; also if dominant parent’s DNA has it
Mutations: spontaneous or environmentally induced

17. Genotype: genetic make-up of a person, containing both expressed and unexpressed characteristics
Defects: both parents give recessive gene for the abnormality; also if dominant parent’s DNA has it
Mutations: spontaneous or environmentally induced
Problems
Genetic and environmental causes; if has genetic marker, environment may trigger. May also trigger without environment. (traits, personality, intellectual, obesity, diabetes)

18. Fertilization to two weeks: germinal stage, zygote divides and becomes complex, implanted into uterus wall- formally beginning pregnancy.
(see pages for development stages)

19. Figure 4.2 Prenatal development Myers: Psychology, Eighth Edition Copyright © 2007 by Worth Publishers

20. Stages of Prenatal Development
Duration
Germinal
Conception to 2 weeks
Embryonic
2 to 8 weeks
Fetal
8 weeks to birth

21. Germinal Stage Development

22. Embryonic stage (2-8 weeks)
Major bodily systems develop
Spontaneous abortion: usually due to chromosomal abnormalities, severely defective embryos. Occurs usually without mother aware (50% end in miscarriage; 15% known to mother)
Fetal Stage (8-birth)
Appearance of bone cells; rapid growth; more complex organ development; begin to interact with environment; learn and remember (sound, voices)

23. Hazards to Prenatal Development
Teratogen: agent causing birth defects
Severity of damage affected by
Dose
Genetic susceptibility
Time of exposure
Effects of prescription and nonprescription drugs

24. Teratogens and Timing of Their Effects on Prenatal Development
Fig. 2.10

25. Teratogen: is a substance that can cross the placental barrier and harm the child. Alcohol and tobacco are perhaps the most common and damaging. Mercury, landfills, lead paint
Fetal Alcohol Syndrome (FAS): combo of retarded growth, face and body malformations, disorders of the nervous system. ADHD symptoms, attention, distractibility, learning difficulties, memory and mood impairment.
Nicotine: low birth weight, miscarriage, retardation, still birth, small head syndrome, medical problems.

26. Marijuana: birth defects, low birth weight, ADHD, learning problems, visual and perceptual skills deficit, impulsivity- impacts frontal lobe.
Cocaine: spontaneous abortion, delayed growth, premature labor. Low birth weight, birth defects, neurological deficits; acute withdrawal following birth; overall, significant neurological deficits.

27. HIV/AIDS: likely to spread it to fetus.
Maternal Illnesses: colds, STDs, general medical problems.
Maternal Stress: wide psychological disorders, deformities. Negative emotional/behavioral
Over 35: for the mother-diabetes, high BP, severe bleeding. Child- premature birth, birth defects, retarded growth.

28. Physical Development— Hazards to Prenatal Development

29. Assessing the Newborn Apgar Scale: heart, reflexes, and color
Birth
Assessing the Newborn
Apgar Scale: heart, reflexes, and color
Brazelton Neonatal Behavioral Assessment Scale (BNBAS)
A sensitive index of neurological competence
Four categories in global terms
Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS)
Analysis of behavior, neurological and stress responses, and regulatory capacities

30. Birth
The Apgar Scale
Fig. 2.11

31. Bonding Needs to occur shortly after birth
Early emotional attachments may create healthy interactions after leaving hospital
Rooming-in arrangements offered
Massages and tactile stimulation for premature infants affect development

32. Recommended now: Comfort your baby:
comfort baby when they cry
feed them when they are hungry
play with them when they are awake
“spoil” them as much as you can! (studies show that baby must learn that they have an effect on their environment, and therefore control over their own experience. Important for cognitive and social development
babies need to know that they can make things happen
being responsive to baby