Chapter 4: Development Flashcards
(130 cards)
period of the zygote
time of conception to two weeks later; blastocyst implants into uterine lining, period of prenatal development mostly driven by genetic factors (rapid cell division)
blastocyst
hollowed out ball of cells that implants into the uterine wall, ultimately to become the developing organism and its support system
ectopic pregnancy
pregnancy that results from the implantation of the blastocyst into the fallopian tubes instead of the uterine wall - woman and zygote at risk
Why are ectopic pregnancies risky?
- uterus can expand (as zygote grows) and contract (to expel fetus)
- fallopian tubes cannot
- pregnancy is terminated to avoid death due to ruptured fallopian tube
What is the defining feature of the period of the zygote?
Rapid cell division
monozygotic
identical twins - one egg fertilized by one sperm and divided into two separate cells with identical DNA (100% shared genetics, same sex)
dizygotic twins
fraternal twins - woman’s ovaries will release more than one egg at a time; two eggs are fertilized by one sperm each (unique genetic makeup)
Many teratogens have been identified, including …
the use of tobacco or alcohol during pregnancy, the use of over-the-counter or prescription medications, and the occurrence of specific viruses or illnesses that can be transmitted from pregnant women to their developing infants
Effects of teratogens depend on…
- dose (how much exposure)
- timing (stage of gestation)
- cumulative effects (more than one teratogen)
Is maternal mental illness a teratogen?
No.
Challenge associated with determining whether an environmental agent acts as a teratogen…
it is unethical to randomly assign pregnant women to an experimental condition (e.g., exposure to teratogens) that might negatively impact their developing infant
When do teratogens exert most of their negative effects?
during the period of the embryo
Teratogens exert seemingly less influence during the period of the zygote, as…
the process of cellular division is largely constrained by biology
Another reason why teratogens exert their biggest effects early in pregnancy—between the second and eighth weeks of gestation—is because….
many women may not realize they are pregnant until after this important period of prenatal development has passed
Infants who have been exposed to alcohol during pregnancy may be identified as having…
fetal alcohol spectrum disorder (FASD)
A recent meta-analysis estimates that approximately __% of women across the globe use alcohol during their pregnancies.
10
Is the dose and timing of alcohol use definitively linked to infant and child outcomes?
No, abstaining is recommended to stay prudent.
Effects of alcohol on developing infant:
- Damage to internal organs (resulting in heart or kidney problems as well as issues with vision or hearing)
- Altered physical characteristics (reduced head size, below-average height
- Smooth patch of skin between the nose and the upper lip
- Cognitive impairments (problems with hyperactivity and inattention, reduced intelligence, and challenges in school)
sleeper effects
issues experienced by infants with FASD that may not be identified until later (e.g., cognitive defects associated with FASD until preschool, such as visual-motor integration and child behaviour problems)
Seemingly for the first time, a child experiences difficulty concentrating in class, potentially as a result of prenatal exposure to alcohol. This is an example of a:
sleeper effect
Four major stages of cognitive development:
- sensorimotor period
- preoperational period
- concrete operational period
- formal operational period (may not be achieved by some)
Who came up with the four stages of cognitive development?
Jean Piaget
Can children skip a stage in cognitive development?
No! (according to Piaget)
Piaget’s theory describes cognitive development in ways that are easily ______ and ______.
accessible and observable