Chapter 3: Genetics, Prenatal Development, and Birth Flashcards
Genetics
are observable characteristics that are inherited and triggered by the genetic sequence inside cell
Genome
every instruction a cell needs to create and maintain your body
Epigenome
is the part of genome that controls gene expression
Genes
contain sections of DNA that create particular proteins
Alleles
are different forms of genes; can affect individual characteristics and disease risks
Zygote
a fertilized egg (46 chromosomes; 23 pairs from sperm and egg)
Sex chromosomes
unique 23rd chromosome pair
Single-gene disorder
are linked to a single gene, it may be possible to predict and prevent disease transmission if the gene is known
Recessive Inheritance Pattern
two copies of the disease-carrying allele
Dominant Inheritance Pattern
one copy of the disease-carrying allele
Polygenic Traits and Diseases
have genetic characteristics that require a trigger or specific influence from the environment to be expressed
Multifactorial Traits and Diseases
are influenced by multiple inherited variables
Epigenome
controls which genes are expressed; can change with age
Monozygotic twins
include twins with nearly identical DNA because they start off as a single zygote that separates into two in the first days after fertilization
Dizygotic twins
include twins that develop when two ova are fertilized by separate sperm
Conception
mature ovum is fertilized by sperm and creates the zygote
The germinal stage
occurs from conception until week 2; the zygote divides and implants into the uterus in the first week
The outer layer of the blastocyst cells forms support structures
- the amniotic sac
- the placenta
- the umbilical cord
The embryonic stage
from implantation until eight weeks; the amniotic sac and placenta protect the developing embryo; the major organ systems and brain are beginning to develop
The fetal period
begins at week 9 and goes through till birth; the fetus rapidly grows
Vision
a fetus will react to light at about 24 weeks
Touch and Pain
at 20 weeks fetus can react to touch and pain
Hearing
fetus will react to loud sounds at 25 weeks; a few weeks later, fetus will react to sounds they hear frequently
Smell and taste
by 26 weeks a fetus can smell and taste
Teratogen
any agent that can cause a birth defect or negatively alter cognitive and behavioral developmental outcomes
Teratology
study of the cause of birth defects
Teratogen damage and severity depends on
- dose
- genetic susceptibility
- time of exposure
fetal programming theory
investigates impact of prenatal experience on lifelong health
SGA
small for gestational age - babies born smaller than expected for their level of development
kangaroo care
skin-to-skin contact with newborn
apgar test
a quick medical evaluation of breathing, activity, responsiveness, and heart rate that assesses which newborns need immediate medical care
rooting reflex
if newborn’s cheek is touched, they will turn their head and open their mouth in preparation for nursing; disappears by 2-3 months
moro reflex
if newborn feels as if they are falling, their arms will swing in and out suddenly; disappears by 5-6 months
palmar grasp
if you press a newborn’s palm, their fingers will curl in; disappears by 5-6 months
plantar grasp
if you press the sole of a newborn’s foot, their toes will curl in; disappears by 9-10 months
babinski reflex
if you run your finger along the sole of a newborn’s foot, their toes will fan out; disappears by 12-24 months
phenotype
your individual observable characteristics
genotype
the genome that contributes you phenotype
