Chatper 2 Flashcards
Prenatal Development
Ideas of development _____
- Used to believe individual was ___
- Aristotle argued for ____
changed over time
pre-formed
epigenesis
Prenatal Development
Epigenesis
the process by which plants, animals and fungi develop from a seed through a sequence of steps in which organs form.
Conception
Gametes (germ cells)(What is it)
Contain half the ______
reproductive cells
(egg and sperm)
Contain half the genetic material of all
other cells in the body
Conception
Meiosis definition
___ chromosomes from mother and ___
chromosomes from father
a type of cell division that produces gametes, or sex cells, like eggs and sperm
23,23
Conception definition
Zygote:
the union of an egg from the mother
and a sperm from the father; fertilization
a fertilized egg cell
Developmental Processes
______ that transform a zygote to embryo to fetus
name them
Four developmental processes that transform a zygote to embryo to fetus
*Mitosis
* Cell migration
* Cell differentiation
* Apoptosis
Developmental Processes
Mitosis
Cell division resulting in two identical daughter cells
Developmental Processes
Cell migration
Newly formed cells move away from point of origin
Developmental Processes
Cell differentiation
Cells start to specialize in structure and function
Developmental Processes
Apoptosis
programmed cell death
Genetically programmed cell death
Developmental Processes
Role of Apoptosis:
Fetal hand plate
* Cell death needed for
development of hand to
create ridges for fingers to
separate
Brief Overview of Prenatal Development
1 week: Zygote travels to ___
2-3 weeks: Embryo forms ___
Week 1: Zygote travels to womb to begin embryo formation
Week 2-3: Embryo forms nervous system, skin, neural tube
Brief Overview of Prenatal Development 13-24 weeks
25-38 weeks
Week 13-24: Basic facial expressions; fetal movements
Weeks 25-38: Fetus size triples; brain and lungs develop; visual/auditory systems functional; fetus capable of learning
Early Development: Support System
Neural tube:
a groove formed in the top layer of
differentiated cells
* Eventually becomes the brain and spinal cord
Early Development: Support System
Amniotic sac:
a transparent, fluid-filled membrane
* Surrounds and protects the fetus
Early Development: Support System
Placenta:
a support organ for the fetus
* Permits exchange of materials
Early Development: Support System
Umbilical cord:
a tube containing the blood
vessels connecting the fetus and placenta
* Nutrients
Early Development: Support System
Cephalocaudal:
areas near head develop earlier than those farther away
Early Development: Support System
Androgens:
class of ___ that include
___
class of hormones that include
testosterone
-Sex differentiation
Early Development
Identical (monozygotic) twins
How it occurs and what genes they have
Twins that result from the splitting in half of the zygote
Each of the two resulting zygotes have exactly same set of
genes