Developmental Psychology PDF

Developmental Psychology Heredity & Prenatal Development JABBARI PSYC SS271 GENETIC HERITABILITY The construction of our body is guided by DNA...

Developmental Psychology Heredity & Prenatal Development JABBARI PSYC SS271 GENETIC HERITABILITY The construction of our body is guided by DNA JABBARI PSYC SS271 2 The Influence of Heredity on Development: GENETIC HERITABILITY Chromosomes and Genes Heredity Genetics Chromosomes Genes JABBARI PSYC SS271 3 GENETIC HERITABILITY ◦ Our DNA is comprised of 23 pairs of chromosomes (46 in total) ◦ Our unique combination of genes is called our genotype, but when used to build a body the features are called our phenotype ◦ Male and female gametes (sperm/ova) contain only one of each pair of chromosomes JABBARI PSYC SS271 4 GENETIC HERITABILITY Conception When the sperm and ova join, a new, full and unique set of chromosomes is created JABBARI PSYC SS271 5  GENETIC HERITABILITY 23 chromosomes come from mother 23 chromosome come form father The 23rd pair are sex chromosomes Male or Female? X X X Y Receive X chromosome from mother Father supplies X or Y chromosome If X = female If Y = male XX XY XX XY JABBARI PSYC SS271 6 Dominant and Recessive Traits Dominant trait Recessive trait Carriers JABBARI PSYC SS271 7 What happens in the process of conception? JABBARI PSYC SS271 8 PRENATAL DEVELOPMENT The first two weeks of development is the germinal stage ◦ Stem cells proliferate to form a hollow ball called a blastocyst ◦ The blastocyst implants into the uterine lining to continue development JABBARI PSYC SS271 9 PRENATAL DEVELOPMENT Weeks 2-8 is the embryonic stage ◦ Stem cells begin to differentiate and specialize ◦ Major anatomical features form and nervous system begin to form JABBARI PSYC SS271 10 PRENATAL DEVELOPMENT ◦ In weeks 4-6 sex chromosomes will either stimulate androgens to direct a male anatomy or will not, producing female anatomy ◦ Electrical activity in nerve cells observed by week 6 JABBARI PSYC SS271 11 PRENATAL DEVELOPMENT Beyond week 8 is the fetal stage ◦ Organs begin to function ◦ Neuronal proliferation ◦ Continued growth and anatomical refinement JABBARI PSYC SS271 12 PREGNANCY A typical pregnancy is 37 to 42 weeks ◦ Pre-term (42) Pregnancy is often divided into three trimesters JABBARI PSYC SS271 13  Chromosomal Abnormalities Down Syndrome Is a trisomy of the 21st chromosome, resulting in intellectual delay, characteristic features, sensory impairment and heart defects ◦ Risk related to maternal age at conception JABBARI PSYC SS271 14 Chromosomal Abnormalities Sex-Linked Chromosomal Abnormalities Hemophelia blood does not clot properly Carried on the X chromosome Colour blindness Red-green colour blindness is most common Rarest among those of Asian, Indigenous, and African descent Carried on X chromosome Muscular dystrophy Weakening of muscles, wasting away, inability to walk, sometimes death JABBARI PSYC SS271 15 Congenital Anomalies Teratogens Any substance or condition that can disrupt normal development, especially during critical periods of development May include use of alcohol or other substances, medications, maternal disease, stress, age. JABBARI PSYC SS271 16 Teratogens Heroin and Methadone: Both substances cross the placenta, causing risks like low birth weight, prematurity, and newborn withdrawal symptoms (e.g., tremors, vomiting, respiratory difficulties). Marijuana (Cannabis): Common during pregnancy. Risks include fetal growth retardation, low birth weight, cognitive and behavioral problems (e.g., hyperactivity, impulsivity). Cocaine: low birth weight, birth defects, and cognitive issues like language difficulties. Affected infants may be excitable or lethargic. JABBARI PSYC SS271 17 Teratogens Alcohol: Crosses the placenta, leading to fetal alcohol spectrum disorder (FASD), facial deformities, intellectual and behavioral deficits. Cigarettes: Nicotine and carbon monoxide reduce fetal oxygen, resulting in impaired motor skills, learning disabilities, and hyperactivity. Second-hand and third-hand smoke, as well as vaping, pose risks like premature birth and congenital disabilities. JABBARI PSYC SS271 18 Genetic Abnormalities Conditions resulting from specific genes or combinations of multiple genes ◦ Cystic Fibrosis ◦ Huntington’s Disease ◦ PKU ◦ Sickle-Cell Anemia JABBARI PSYC SS271 19 Prenatal Assessment Chorionic villus sampling ◦ Extracts tissue from the placenta for laboratory testing Amniocentesis ◦ Extracts amniotic fluid containing discarded fetal cells Ultrasound ◦ Using sound waves to obtain information about fetus Blood test ◦ Used to identify genetic abnormalities such as Sickle-Cell Anemia JABBARI PSYC SS271 20 PRENATAL ASSESSMENT Fetal Ultrasound 21 Infertility Approximately 1 in 6 Canadian couples will have difficulties conceiving a child. A woman’s reproduction begins to decline in her mid- to late 20s. Female Infertility Irregular or lack of ovulation hormones, stress, and malnutrition Infections (e.g., pelvic inflammatory disease, PID) Endometriosis – obstructs fallopian tubes JABBARI PSYC SS271 Infertility Male Infertility Low sperm count (most common) Genetic factors Environmental poisons Diabetes Sexually transmitted infections (STIs) Overheating of the testes or pressure Aging Deformity of sperm (motility – prostate or hormonal problems or scar tissue from STIs) JABBARI PSYC SS271  Other Ways of Becoming Parents Assisted Reproductive Technology (ART) ART is the term for any medical assistance provided that enables conception to take place: drug treatment artificial insemination : Addresses low sperm count; low sperm motility in vitro fertilization : used when the fallopian tubes are blocked or the father has low sperm motility surrogacy JABBARI PSYC SS271