lifespan development ch2

Phenotype

The way an individuals genotype is expressed in observable and measurable characteristics

Fetal alcohol spectrum disorders (FASD)

are a cluster of abnormalities and problems that appear in the offspring of mothers who drink alcohol heavily during pregnancy

meiosis

cell division that occurs to form eggs and sperm, called a zygote

mitosis

cells nucleus duplicates itself

placenta

consists of a disk-shaped group of tissues in which small blood vessels from the mother and the offspring intertwine but do not join.

umbilical cord

contains two arteries and one vein, connects the baby to placenta

psychoactive drugs

drugs that act on the nervous system to alter state of consciousness, modify perceptions, and change moods.

teratogen

is any agent that can potentially cause a birth defect or negatively alter cognitive and behavioral outcomes.

endoderm cell layer

is embryos inner layer of cells, which will develop into the digestive and respiratory system

mesoderm cell layer

is embryos middle layer of cells, which will become the circulatory system, bones, muscles, excretory system, and reproductive system.

ectoderm cell layer

is embryos outermost layer which will become the nervous system and brain, sensory receptors (ears, nose and eyes) and skin parts (hair and nails)

fetal period

lasting about seven months, the prenatal period between two months after conception and birth in typical pregnancies.

embryo

mass of cells at two to eight weeks after conception. Three layers of cells form. The embryos endoderm is the inner layer. Mesoderm is the middle later. Ectoderm is the outermost layer.

organogenesis

organ formation that takes place during the first two months of prenatal development

germinal period

period of prenatal development that take splace in the first two weeks after conception. It includes the creation of the zygote, continued cell division and the attachment of the zygote to the uterine wall. Germinal period ends when the blastocyst attaches to the uterine wall.

blastocyst

the inner layer of cells that develops during the germinal period. These cells later develop into the embryo

trophoblast

the outer layer of cells that develops in the germinal period. These cells provide nutrition and support for the embryo

embryonic period

the period of prenatal development that occurs two to eight weeks after conception. During the embryonic period, the rate of cell differentiation intensifies, support systems for the cells form, and organs appear.

epigenetic view

the view that states that development is the result of an ongoing, bidirectional interchange between heredity and the environment