Chapter 2

Question 1

What are Genes?

Answer 1

-specific sequence of nucleotides and are recipes for making proteins.

Question 2

What is the Genome?

Answer 2

-the full set of genes
-it is the master blueprint for making an entire organism

Question 3

What is Mitosis & Meiosis?

Answer 3

-mitosis: the cell’s nucleus making an exact copy of all the chromosomes and splitting into two new cells
-meiosis: the gamete’s chromosomes duplicate, and then divide twice resulting in four cells containing only half the genetic material of the original gamete

Question 4

What is Genotype & Phenotype?

Answer 4

-genotype: the sum total of all the genes a person inherits.
-phenotype: the features that are actually expressed (hair, skin, eye colour; cognitive traits, personality)

Question 5

What is Homozygous vs Heterozygous?

Answer 5

-homozygous: when we receive the same version of a gene from our mother and father.
-heterozygous: when we receive a different version of the gene from each parent.

Question 6

What are Dominant and Recessive genes?

Answer 6

-dominant genes express themselves in the phenotype even when paired with a different version of the gene.
-recessive genes express themselves only when paired with a similar version gene.

Question 7

What is incomplete dominance and carriers?

Answer 7

-incomplete dominance: when the dominant gene doesn’t completely suppress the recessive gene.
-carriers: those who have inherited only one recessive-gene.

Question 8

What are sex-linked genetic disorders?

Answer 8

-the defective gene is found on the X-chromosome.
-males have only 1 X-chromosome so they are at greater risk for sex-linked disorders due to a recessive gene

Question 9

What is Chromosomal Abnormality, and an example?

Answer 9

-when a child inherits too many or too few chromosomes.
-Trisomy 21/Down Syndrome: when there are three rather than two 21st chromosomes; exhibits an intellectual disability.

Question 10

What is sex-linked chromosomal abnormality and 2 examples?

Answer 10

-when the abnormality is on 23rd pair.
-Turner syndrome: when part or all of one of the X chromosomes is lost and the resulting zygote has an XO composition.
-Klinefelter syndrome (XXY): when an extra X chromosome is present in the cells of a male

Question 11

What is genetic counseling?

Answer 11

-a service that assists individuals identify, test for, and explain potential genetic conditions that could adversely affect themselves or their offspring.

Question 12

What are Polygenetic Characteristics?

Answer 12

-physical, behavioural, and psychological traits are polygenetic –> influenced by many genes (no dominant recessive gene pairing)
–e.g., skin tone
-further influenced by the environment

Question 13

What are behavioural genetics?

Answer 13

-the scientific study of the interplay between the genetic and environmental contributions to behaviour
-also called the nature vs nurture debate

Question 14

What do twin studies tell us about contribution of a trait/

Answer 14

-monozygotic: share 100% of their genome; dizygotic: share 50% of their genome
-when there is more phenotypic variation among dizygotic twins and little phenotypic variation among monozygotic twins, it suggests that the genetic contribution to that trait is strong.

Question 15

What is the heritability quotient?

Answer 15

-determined by the degree of relatedness; used to quantify variance proportion of given trait
-higher proportion means greater role of genetics in determining phenotypes
-H2 = variance due to genes/total variance

Question 16

What are Genotype-Envrionment Correlations?

Answer 16

-the processes by which genetic factors contribute to variations in the environment
-3 types: passive, evocative, active/niche-picking

Question 17

What is passive genotype-environment correlation?

Answer 17

-parents pass on genes for a particular trait to their offspring, and provide an environment that facilitates/matches the genetic tendency
-ex: musical parents –> musical children

Question 18

What is evocative genotype-envrionment correlation?

Answer 18

-the genotypes of the child produce phenotypes that elicit certain types of physical and social environments.
-ex: happy/outgoing kids receive positive reactions/reinforcement –> behaviour is then enhanced

Question 19

What is active/niche-picking genotype-environment correlation?

Answer 19

-when individuals seek out environments that support their genetic tendencies.
-ex: kid is good at a sport in school –> asks their parents for lessons to support their tendencies

Question 20

What are Genotype-Environment Interactions?

Answer 20

-genetic susceptibility to the environment.
-environmental effects on behaviour differ based on the genotype, especially stressful environments on genetically at-risk children.

Question 21

What is Epigenetics?

Answer 21

-epigenetics studies modifications in DNA that affect gene expression and are passed on when the cells divide.
-turning genes on and off (expressing or depressing their code); as a result of nutrition, stress, and teratogens

Question 22

What are the milestones of prenatal development?

Answer 22

First Trimester
-germinal period (1-2 weeks)
-embryonic period (3-4 & 5-8 weeks)
-fetal period (9-12 weeks)
Second Trimester
-fetal period (13-24 weeks)
Third Trimester
-fetal period (25-38 weeks)

Question 23

What happens during the germinal period?

Answer 23

-zygote divides and forms blastocyst, which implants in uterus and begins forming the amnion, placenta, and umbilical cord.

Question 24

What happens during the embryonic period?

Answer 24

-three layers from: the ectoderm, mesoderm, and endoderm
-neural tube develops and produces neurons
-heart begins beating
-ribs, muscles, and digestive tract form

Question 25

What happens during the fetal period in the first trimester?

Answer 25

-genitals form and release sex hormones
-fingernails, toenails, and taste buds develop
-heartbeat audible with stethoscope

Question 26

What happens during the fetal period in the second trimester?

Answer 26

-mother feels movement
-fetus kicks, turns, hiccups, sucks thumb, breathes amniotic fluid
-responds to sounds, especially music and familiar voices

Question 27

What happens during the fetal period in the third trimester?

Answer 27

-lungs develop fully
-over two-thirds of birth weight is gained
-brain development accelerates; sleep-wake cycles resemble newborn’s

Question 28

What are Teratogens?

Answer 28

-environmental factors that can contribute to birth defects.

Question 29

What factors influence prenatal risks?

Answer 29

-timing of exposure
-amount of exposure
-number of teratogens
-genetics
-being male or female (males more likely to experience damage due to teratogens than females)

Question 30

What are some examples of Teratogens?

Answer 30

-alcohol (Fetal Alcohol Spectrum Disorders)
-tobacco
-prescription/over-the-counter drugs
-illicit drugs (Neonatal abstinence syndrome; child in withdrawal)
-pollutants (lead, pesticides, bisphenol A, radiation, mercury)
-toxoplasmosis (infection from parasite)
-stds
-HIV/AIDS
-german measles (or rubella)

Question 31

What maternal factors affect the fetus?

Answer 31

-mothers over 35
-teenage pregnancy
-gestational diabetes
-high blood pressure (hypertension)
-Rh disease
-weight gain during pregnancy
-stress
-depression
-paternal impact

Question 32

What are the 3 techniques for prenatal assessment?

Answer 32

-ultrasound: test where sound waves are used to examine fetus.
-amniocentesis: procedure where a needle is used to withdraw a small amount of amniotic fluid and cells from the sac surrounding the fetus and later tested (miscarriage risk)
-chorionic villus sampling: procedure where a small sample of cells is taken from the placenta and tested (miscarriage risk)

Question 33

What are the minor complications of pregnancy?

Answer 33

-nausea (first 3-4 months of pregnancy due to high levels of estrogen levels),
-heartburn,
-gas,
-hemorrhoids,
-backache,
-leg cramps,
-insomnia,
-constipation,
-shortness of breath
-varicose veins

Question 34

What are the major complications of pregnancy?

Answer 34

-ectopic pregnancy: zygote attaches to the fallopian tube
-preeclampsia/toxemia: sharp rise in blood pressure, kidney problems, and swelling of the hands, feet, and face during the third trimester of pregnancy.
-eclampsia: when preeclampsia causes seizures.
-maternal mortality
-spontaneous abortion (due to chromosomal abnormalities)

Question 35

What is the Lamaze Method?

Answer 35

-teaching the woman to be in control during delivery.
-includes learning muscle relaxation, breathing through contractions, having a focal point during contractions and having a support person

Question 36

What are the stages of birth?

Answer 36

-Stage 1/Labour: uterine contractions; longest stage as it lasts 12-16 hours (first child) or 6-9 hours
-Stage 2/Delivery: pushing the baby through the birth canal; stage lasts 10-40 minutes; episiotomy (incision between vagina & anus) is done to avoid tearing
-Stage 3/Afterbirth: placenta is delivered 20mins after delivery; episiotomy is stitched up

Question 37

What is a Cesarean section?

Answer 37

-surgery to deliver the baby by being removed through the mother’s abdomen
-done when unexpected problems occur during delivery, such as:
–health problems in the mother;
–signs of distress in the baby;
–not enough room for the baby to go through the vagina
–position of the baby (head not in the downward position)

Question 38

What is induced birth?

Answer 38

-delivered before labour begins.
-may be recommended for a variety of reasons when there is a concern for the health of the mother or baby.

Question 39

How is the newborn/neonate assessed?

Answer 39

-newborn is assessed 1 minute & 5 minutes after birth; 2nd assessment should indicate improvement with higher score
-the APGAR scoring method is used to assess key indicators of health: Appearance, Pulse, Grimace (Babinski reflex test), Activity (touching the baby’s palm), Respiration
-APGAR score of 5 or less is cause for concern

Question 40

What are 4 potential problems with the newborn?

Answer 40

-anoxia: temporary lack of oxygen to the brain; brain damage, death
-low birth weight: baby weighs less than 5 pounds 8 ounces (2500 grams); difficulty maintaining body temperature, higher risk of infection and developing cerebral palsy, increases psychiatric disorders in adulthood
-preterm: baby born at less than 37 weeks; respiratory distress syndrome
-small-for-date: birth weights below expectation based on their age; 4 times higher death rate