Chapter 2 Flashcards
Chromosomes
- structures that contain genetic material
- we have 23
DNA
the molecule that composes one chromosome and is the biochemical basis of heredity
gene
the biochemical instruction that is produced by a group of chemical compounds within a strand of DNA
genotype
a person’s complete set of genes
phenotype
observable features that result from the interactions between a person’s genes and the environment
behavioral genetics
study of the extent to which genetic and environmental differences contribute to difference in traits
dizygotic twins
- two zygotes/fertilized ova
- most common
monozygotic twins
- one zygote that divides into two individuals
- share genes
twin studies
studies of twins, both identical and fraternal, reared apart and together
adoption studies
are adopted children more similar to biological parents or to adoptive parents?
family studies
studies of siblings with different degrees of genetic similarity and vary environments
3 stages of prenatal development
- zygote
- embryo
- fetus
conception
- once a month an ovum (female egg)
- moves through fallopian tube to uterus
- uterus is where baby develops during pregnancy
- if not fertilized it disintegrates and is flushed away with menstruation
zygote
- month 1
- fertilized egg reaches the uterus and attaches itself to the uterus
- cell multiplication begins
- internal organs and circulatory system begins to form
- cell division takes place at the end of two weeks
- heart begins to beat
- small bumps show beginnings of arms and legs.
embryo
- month 2
- all major organ systems develop
- placenta and umbilical cord develop
- amniotic fluid surrounds baby
- face and limbs take shape
fetus
- month 3 (longest period)
- nostrils, mouth, lips, teeth buds, and eyelids forms
- arms, legs, fingers and toes are almost complete
- all internal organs present - but aren’t ready to function
- the genital organs can be recognized as male or female
lanugo
thick downy hair covering fetus
vernix
a protective coating that forms on baby’s skin
mother’s nutrition
- balanced diet essential
- proteins, vitamins, and minerals
- increase caloric intake 10-20%
Risk factors
- nutrition
- stress
- age
- teratogens
teratogen
- an agent that causes abnormal prenatal development
- drugs, disease, environmental hazards.
fetal medicine
treating prenatal problems before births
genetic engineering
replacing defective genes with synthetic normal ones
infant mortality rate
percentage of infants who die before their 1st birthday
