Chapter 3 Flashcards
Mitosis
A single-cell develops into a complex human being as DNA replicates itself
Meiosis
Only about sex cell production-cell division. halves the number of chromosomes and crossover takes place`
Monozygotic
Identical twins
zygote separates into 2 clusters of cells that have the same DNA
Dizygotic
Fraternal twins
Two ova are released and both are fertilized by two separate sperm. They have different DNA
Homozygous
both alleles are alike and child will display the trait
Heterozygous
the alleles differ and the child will carry the gene but may or may not display it
X-linked inheritance
if the mother has one normal and one abnormal allele on her chromosomes. by looking at the possible combinations of the parents’ alleles, that 50% of the girls will carry the disorder and 50% of the males will likely have the disorder
Female chromosomes
XX
Male chromosomes
XY
Germline Mutation
The environment changes your DNA and you pass it on to your kids BECAUSE OF THE SEX CELLS (mothers exposed to radiation before conception)
somatic Mutation
Normal body cells mutate. can happen at anytime throughout your life. genetic suseptibility
Risk factors for down syndrome
AGE 20 years old-- 1 in 1900 births 25-- 1 in 1200 30-- 1 in 900 33-- 1 in 600 48-- 1 in 15
Sperm production and viability
Men produce over 300 million a day
The swim upstream causes most to die
only 300-500 will reach the ovum if one is present
can live for up to 6 days and can die in wait for the ovum, which survives only one day after being released into the Fallopian tube
Ectoderm
nervous system and skin
mesoderm
muscles and organs
endoderm
digestive system and urinary tract
Zygote
conception to 2 weeks. finding food and shelter
embryonic stage
3-8 weeks. most susceptible to environment. laying the groundwork for basic structure and for internal organs
Fetus period
9 weeks-birth growing and finishing stage
teratogens
anything that causes problems in pregnancy– chemicals, radioactive exposure, taking too many vitamins, smoking (epigenetic issue) drug, alcohol use. incredibly devastating during the embryonic stage.
Fetal activity and postnatal abilities
fetal activity may be an indicator of healthy neurological development
there is a relationship between active fetuses and children who were more able to handle frustration .
higher fetal activity predicts a more active infant
effects of Tobacco use during pregnancy
Low birth weight
Likelihood of increases in miscarriges, prematurity, cleft palate and cleft lip, impaired heart rate and breathing during sleep, infant death, asthma and cancer
Effects of alcohol use during pregnancy
fetal alcohol spectrum disorder
fetal alcohol syndrome
Partial fetal alcohol syndrome
alcohol related neuro-developmental disorder
Fetal alcohol spectrum disorder
encompasses a range of physical, mental and behavioral outcomes due to pre-natal alcohol exposure
Fetal alcohol syndrome
slow physical growth, a pattern of 3 face abnormalities (short eyelids, thin upper lip, flattened philtrum, indentation running from bottom of nose to center of upper lip), brain injury
Partial fetal alcohol syndrome
2 of 3 facial abnormalities from FAS, brain injury
Alcohol related neuro-developmental disorder
3 areas of mental functioning are impaired, despite typical physical growth and lack of facial abnormalities
Health effects of folic acid during pregnancy
Need to have a sufficient amount of folic acid during embryonic stage when spine is forming.
intake of Vitamin C prevents neural tube defects and spina bifida.
Helps the mother carry full term
maternal age as it relates to pregnancy
the fetus is likely to be more healthy and be carried to full term if the mother is younger
Best time to have babies is in the 20’s
Effects of labor and delivery medication
Analgesics—> drugs used to relieve pain. Given in mild doses during labor to help mother relax
Anesthetics—> strong painkiller that blocks sensation.
Epidural—> regional pain-relieving drug delivered continuously though a catheter in a small space in the lower spine. limits pain to the pelvic region so the mother is able to push. labor and delivery are prolonged and chances of c-section increase.
New childbirth trends
sitting upright home delivery water birth natural birth medicated birth
Sitting upright birthing
Increases blood flow to the baby
shorter labor with stronger contractions and more effective pushing
mother can see the delivery and can work with doctor or widwife on how to push
less likely to use pain relieving medication
home delivery
mostly handled by certified nurse mid-wives
done for the comfort of the home, to avoid uneccesary medical procedures and costs and to have greater control of the baby after birth
if attendants are not prepared to handle emergencies, infant death is high
water birth
warm tub of water that supports weight , relaxes and provides freedom to move into any position
reduced stress, shorter labor and greater likelihood of medication-free delivery
medicated birth
epidural or birth will pain killers
Stage 1 of labor
Dilation and effacement of the cervix: longest stage of labor, lasting an average of 12-14 hours of first birth and 4-6 with later births. contractions of the uterus gradually become more frequent and powerful causing the cervix or uterine opening to widen and thin to nothing forming a clear channel form the uterus into the birth canal or vagina
Stage 2 of labor
delivery: 50 minutes for a first baby and 20 min for later babies. strong contraction of the uterus continue but the mother feels a natural urge to push. forcing the baby down and out.
Stage 3 of labor
Birth of the placenta: labor comes to an end and with a few final pushes the placenta separates form the wall of the uterus and is delivered in about 5-10 minutes
Canalization of human behavior
tendency of hereditary to restrict development of some characteristics to just one or two outcomes
things that tend to naturally unfold—> toddler learning to walk around 1 year of age
Passive correlations
when your genes match your environment but not because you chose it
(child in an athletic environment because the parents were athletic)
Evocative correlations
Based on appearance
if you are beautiful or attractive people tend to treat you better or think you are smarter
Active correlations
niche picking. finding environments that reflect your genetic tendencies thereby further developing them.
Pros and cons of reproductive technologies
Donor insemination: injection of sperm from an anonymous man into a woman. lets women without a male partner become pregnant. 70-80% successful.
In vitro fertilization: ova are removed from a woman and fertilized with sperm in a dish of nutrients. Once an ovum is fertilized it duplicates and is then injected into the mother’s uterus. Used to reat women whose fallopian tubes are permanently damaged. helps overcome male fertility problems. fertilized ovum can be frozen and and stored in embryo banks for later use. 35% successful. success declines with age. 50% result in multiple births. low birth weight trends
controversy: sex selection
Surrogate motherhood: femal is fertilized with male’s sperm and then turns the baby over to him after the child is born. Child is then adopted by his partner. Surrogate is paid a fee
New reproductive frontiers: doctors can impregnate a postmenopausal women. selecting ova or sperm based on gender, IQ, or physical characteristics.
Fertility drugs often result in multiple fetuses
A case of Epigenesis: smoking during pregnancy alters gene expression
research shows that environment effects the way that genes operate but does not change the genome itself.
risk factors: attention deficit disorder (ADHD)
most common disorders in children
symptoms—> inattention, impulsivity and overreactivity. serious academic and social problems.
prenatal exposure to toxins may modify the genes activity.
Children whose mothers smoked during pregnancy scored higher on the ADHD behavior scale.
