LESSON 5.1: Conception and Prenatal Development Flashcards
beginning of development marked by the union of the sperm cell with the egg cell
conception
developmental period within the womb between conception and birth
prenatal development
prenatal development can be divided into _______ periods
3
3 periods of prenatal development
- germinal period
- embryonic period
- fetal period
includes the creation of the zygote, continued cell division, and the attachment of the zygote to the uterine wall
germinal period
rate of cell differentiation intensifies, support systems for the cells form, and organs appear
embryonic period
growth and development continue during this time
fetal period
3 layers of cells
- endoderm
- mesoderm
- ectoderm
inner layer of cells; primarily develops internal body parts
endoderm
outermost layer, which will become the nervous system and the brain, sensory receptors
ectoderm
middle layer; develops parts that surrounds internal areas
mesoderm
life support systems for the embryo forms _____
rapidly
life support systems for the embryo:
- amnion
- umbilical cord
- placenta
process of organ formation during the first two months of prenatal development
organogenesis
inheritance of genes
heredity
heredity is the transmission of ______ from parents to offspring
genetic traits
state of having different and observable traits or characteristics within a population
variation
variation arises due to ____ and _____
- mutation
- genetic recombination
sudden change in the gene sequence, produces new alleles and introducing genetic variability
mutation
exchange or random mixing of genetic chromosomes with different gene combinations producing new rearrangements
genetic recombination
“Father of genetics”
Gregor Johann Mendel
Mendel proposed the principles of inheritance through a ____ experiment
pea plant breeding
main experiments of mendel
- monohybrid cross
- dihybrid cross
examines inheritance of two traits or characteristics at once
dihybrid cross
examines inheritance of a single trait
monohybrid cross
3 principles of inheritance
- principle of segregation
- principle of independent assortment
- principle of dominance
random genetic inheritance from both parents allows genetic differentiation in offspring
principle of independent assortment
each gamete formed carries only one allele, which causes the offspring to acquire one factor from each parent
principle of segregation
the presence of a dominant allele will always mask the presence of a recessive allele
principle of dominance
can be produced not only by an abnormal number of chromosomes but also by harmful genes
abnormalities
produced by a harmful gene
gene-linked abnormalities
occur when the individual inherits too many or too few chromosomes
chromosomal abnormality
5 chromosomal abnormalities
- down syndrome
- turner syndrome (XO)
- klinefelter’s syndrome (XXY)
- fragile X syndrome
- XYY syndrome
8 gene-linked abnormalities
- cystic fibrosis
- diabetes
- hemophilia
- huntington’s disease
- phenylketonuria
- sickle cell anemia
- spina bifida
- tay sachs disease
males have an extra X chromosome that causes physical abnormalities
klinefelter syndrome (XXY)
abnormality in the X chromosome that can cause intellectual disability, learning disabilities, or short attention span
fragile X syndrome
caused by the presence of an extra chromosome 21 that causes mild to severe intellectual disability and physical abnormalities
down syndrome
an extra chromosome Y in males that can cause above-average height
XYY syndrome
a missing X chromosome in females can cause intellectual disability and sexual underdevelopment
turner syndrome (XO)
glandular dysfunction that interferes with mucus production
cystic fibrosis
delayed blood clotting causes internal and external bleeding
hemophilia
blood disorder that limits the body’s oxygen supply which can cause joint swelling, heart failure, and kidney failure
sickle-cell anemia
______ and ________ are hampered in cystic fibrosis, resulting in a shortened life span
- breathing
- digestion
central nervous system deteriorates, producing problems in muscle coordination and mental deterioration
huntington’s disease
metabolic disorder that causes intellectual disability and hyperactivity when left untreated
phenylketonuria
deceleration of mental and physical development caused by an accumulation of lipids in the nervous system
tay sachs disease
neural tube disorder that causes brain and spine abnormalities
spina bifida
environmental hazard to prenatal development
teratogen
considerations in determining the type and amount of damage from exposure to a particular teratogen
- timing of the exposure
- amount of exposure
- number of teratogens
- genetics
- being male or female
factors influencing prenatal risks
- alcohol
- tobacco
- illicit drugs
- pollutants / environmental hazards
children of substance abusing parents
illicit drugs
when the baby underwent drug withdrawal after birth
neonatal abstinence syndrome
cause of neonatal abstinence syndrome
the baby’s mother used an addictive drug during pregnancy, hence the baby got addicted to the drug before birth
leading preventable cause of intellectual disabilities in children
alcohol
alcohol is one of the most commonly used ____
teratogen
dangerous chemicals that the fetus is exposed to when a pregnant woman smokes
- nicotine
- carbon monoxide
- tar
pollutants / environmental hazards:
- lead
- radiation
- toxoplasmosis
effects of ____:
- fertility problems
- prematurity
- miscarriage
lead
effects of _____ to born babies:
- eye infections
- enlarged liver and spleen
- jaundice
- pneumonia
toxoplasmosis
effects of ____:
- slow down the baby’s growth
- cause birth defects
- affect brain development
- cancer
- miscarriage
radiation
maternal factors:
- maternal diseases
- maternal age
- emotional states and stress
maternal age that affects pregnancy
- mothers over 35 years old
- teenage pregnancy
paternal factors:
- paternal age
- men’s exposure to pollutants
- paternal smoking
- relationship with the mother
can help keep the mother and the baby healthy
prenatal care
prenatal care:
- schedule a visit to the doctors
- get regular prenatal care and don’t miss an appointment
- follow and adopt healthy habits
prenatal assessment:
- ultrasound
- amniocentesis
- chorionic villus sampling
procedure in which a needle is used to withdraw a small amount of amniotic fluid and cells from the sac surrounding the fetus and later tested
amniocentesis
procedure in which a small sample of cells is taken from the placenta and tested
chorionic villus sampling
test in which sound waves are used to examine the fetus
ultrasound
