2 to 3 minutes apart.
7 to 8 minutes apart.
10 to 20 minutes apart.
30 to 40 minutes apart.
Ensure that each generation receives a constant quantity of genetic material.
Stimulate the production of zygotes.
Prevent damaged genes from crossing over to the next generation.
Regulate the process of mitosis.
Feels a natural urge to squeeze and push with her abdominal muscles.
Pushes out the placenta.
Has contractions 8 to 10 minutes apart.
Transitions as her cervix opens completely.
Either an X or a Y chromosome.
Only short chromosomes.
An X chromosome.
All the genetic material the human organism needs.
Mothers who are low in intelligence tend to give birth to more children.
The parents of such families are more likely to divorce.
Mothers tend to be too busy to foster their children’s education.
The homes of large families tend to be full of noise and other distractions.
Received too little oxygen during the birthing process.
Has a well-developed brain that enables quick learning in the first few months.
Bruised the mother’s cervix.
Produced the proper amount of cortisol.
Much higher in industrialized nations.
Slightly lower in Asia than elsewhere.
The same around the world.
Steadily rising in North America.
Mental alertness and hand-eye coordination
The speed with which the infant begins nursing
Breathing, blinking, and kicking
Heart rate, respiratory effort, reflex irritability, muscle tone, and color
Conditions once thought to be due to dominant-recessive inheritance actually result from multiple genes.
Heterozygous individuals are not always carriers of recessive traits.
Hair color and facial features are reasonably accurate predictors of inherited disabilities.
Inherited recessive disorders do not always lead to untreatable conditions.
Make hospital birth as comfortable and rewarding as possible.
Introduce European-style freestanding birth centers to North America.
Remove doctors entirely from the birthing experience.
Persuade women to have their babies at home.
The risk of malaria is slightly higher in Canada.
More African Canadians are recent immigrants than African Americans.
Incomplete dominance patterns are more common throughout the entire Canadian population
More African Canadians live at higher altitudes than African Americans.
Within 6 hours before or after ovulation.
During the week of ovulation.
On the day of or during the 2 days preceding ovulation.
During the 2 hours before or after ovulation.
Are more likely to have an episiotomy.
Prefer lying flat on their backs with their feet in stirrups.
Are less likely to have cesarean births.
Tend to be more nervous and, therefore, experience more birth complications.
Children inherit certain parent-specific diseases.
The rate of sickle cell anemia is rising among North Americans of European descent.
Females are more likely to suffer the effects of X-linked inheritance.
Fragile X syndrome results in 2 to 3 percent of autism cases.
Blastocyst burrows into the uterine lining.
Sperm penetrates and fertilizes the ovum.
Trophoblast forms the chorion.
Amnion encloses the developing organism.
Mistakes during meiosis.
Particular intellectual deficits.
Women who have had three or more pregnancies.
Men with XYY syndrome.
Women of advanced maternal age.
Individuals with Down syndrome.
It often requires more ova than most women produce.
Success declines steadily with age.
That rate is far lower when the man has fertility problems.
It can increase the risk of X-linked disease.
The availability of healthy babies in those regions has declined.
Adoptable children in their own countries are often past infancy.
Adopted children tend to have fewer learning and emotional difficulties.
They can select children like themselves in personality and background.