CH02- Prenatal Development Flashcards
zygote | ˈzīˌɡōt |
The new cell formed by the process of fertilization.
gametes | ˈɡamˌēt, ɡəˈmēt |
The male and female reproductive cells (sperm and ovum, respectively) that unite during sexual reproduction to form a zygote (fertilization).
chromosomes
rod-shaped portions of DNA that are organized in 23 pairs.
In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46.
mitosis
a process of cell duplication, or reproduction, during which one cell gives rise to two genetically identical daughter cells. / The duplication and distribution of chromosomes.
monozygotic twins
Twins who are genetically identical.
dizygotic twins
Twins who are produced when two separate ova are fertilized by two separate sperm at roughly the same time.
genotype
The underlying combination of genetic material present (but not outwardly visible) in an organism.
phenotype
An observable trait.
Down syndrome
A disorder produced by the presence of an extra chromosome on the twenty-first pair; aka “mongolism”.
CVS (chorionic villus sampling)
A test used to find genetic defects that involves taking samples of hair-like material that surrounds the embryo. Done at 8 to 11 weeks.
Temperament
Patterns of arousal and emotionality that represent consistent and enduring characteristics in an individual.
Fertilization
The process by which a sperm and an ovum (male and female gametes) join to form a single new cell (zygote).
Prenatal development
Stages of the Prenatal Period:
- Germinal (fertilization to 2w)- shortest stage; blastocyst travels to and implants in the uterus.
- Embryonic (2w to 8w)- Organism firmly secures to the uterus and called an embryo (3 layers: ectoderm, endoderm, mesoderm). Development of major organs and basic anatomy.
- Fetal (8w to birth)- Organism now called a fetus.
Blastocyst
The fertilized egg.
Endoderm
The inner layer of the embryo, produces the digestive system, liver, pancreas, and respiratory system.
Artificial insemination
A process of fertilization in which a man’s sperm is placed directly into a woman’s vagina by a physician.
Age mother risk
> = 30
adolescence
Aids (acquired immune deficiency syndrome)
if mothers with AIDS are treated with antiviral drugs such as AZT during pregnancy, < 5% of infants are born with the disease.
Marijuana
used during pregnancy can restrict the oxygen that reaches the fetus. Its use can lead to infants who are irritable, nervous, and easily disturbed.
Children exposed to marijuana prenatally show learning and memory deficits at the age of 10.
FAE (fetal alcohol effects)
A condition in which children display some, though not all, of the problems of fetal alcohol syndrome due to the mother’s consumption of alcohol during pregnancy.
