the sperm swims into the fallopian tube, penetrates the wall of ovum
Where does fertilization of the ovum take place in a normal pregnancy?
Chromosomes are composed of what?
strings of genetic material
What is the term used to describe cells that unite at conception?
What is the difference between gametes and all other body cells?
gametes=sperm, ovum=each contain 23 single chromosomes
At how many weeks of gestation will there be prenatal sex differentiation?
between 4 and 8 weeks
Describe an individuals unique genetic blueprint, which is created from genes contributed by both parents?
Seth has dark hair and dark eyes, even though his biological mother is fair skinned. Seth's hair and eye color are part of his ____.
What is true of a trait controlled by a dominant gene?
it will show up in his/her phenotype
Lisa has red hair, which comes from a recessive gene. This must mean that Lisa received the gene from..
Under what circumstance(s) will a recessive gene be expressed?
both parents carry the gene
My father has type A blood and my mother has type O blood. What will my blood type be?
Give an example of the expressivity of genes?
meaning that the degree to which any gene influences phenotypes varies from person to person
What is the term for the pattern of inheritance in which many genes influence a trait?
Skylar has brown eyes, thin lips, and curly brown hair. Which of this traits is polygenic?
Which is true of a trait that is passed through mitochondrial inheritance?
blondness=example; children inherit genes that are carried in structures called mitochondria which are found in fluid that surrounds the nucleus of the ovum before it is fertilized
Recent research has found that diseases that appear as we age may be a result of ____.
Define genomic imprinting.
a chemical label that identifies each gene as coming from mom or dad
Describe physical traits which are influenced by both genes and the environment?
Phenylketonuria is an example of ____?
What percent of congenital disorders are a result of harmful genes or faulty chromosomes?
What is caused by a gene on the X chromosome?
Most sex-linked disorders are caused by what?
the recessive gene
Which of the genetic disorders usually does not express symptoms until adulthood?
What is a trisomy?
condition in which a child has 3 copies of specific autosome
What is the prognosis for children born with trisomy 13 or 18?
not good, few live past age 1
Which individuals has the greatest risk for bearing a child with trisomy 21?
as a woman's age goes up, so does the risk
Randy is taller than average and has larger than usual teeth. Some people used to think that people like Randy would be aggressive and not very bright. With which of the following was Randy most likely born?
extra Y chromosome
What is the most common sex-chromosome anomaly?
XXY pattern, Klinefelter's syndrome
What happens during the first trimester of pregnancy?
zygote implants in the women's uterus lining; cervix thickens and secretes mucus to protect zygote; morning sickness
Not long after Leila found out she was pregnant, she began having pain. When she went to her doctor, she was told that the zygote had implanted in her fallopian tube rather than her uterus. What type of pregnancy is this?
What is associated with the second trimester of pregnancy
increases in appetite
What is a condition that can cause a baby to grow too rapidly and result in premature labor or an infant that is too large for a vaginal birth?
Jan is becoming emotionally attached to her unborn fetus. Her breasts are secreting colostrum. Jan is most likely in which trimester?
Which term explains why the human brain develops before the reproductive system?
What is the best example of the proximodistal principle of development during the prenatal period?
structures toward center of the body develop first, such as rib cage develops before toes and fingers
The embryonic stage of gestation covers which time period?
2 to 8 weeks
A blastocyte is floating inside of Sandy's uterus. In which stage is Sandy's pregnancy?
What is formed from cells from the outer layer of the blastocyte and the uterine wall?
Organogenesis is what?
technical term for organ development
At what point does the fetal period begin?
beginning at 8 weeks to birth
When does a developing infant begin to respond to sound?
week 13 to 18
Ann notices that her fetus has begun to kick and move. Her physician tells her that she can hear a heartbeat with a stethoscope. Ann is most likely at what point in her pregnancy?
week 25 to 28
What best describes neuronal proliferation?
pace of neural formation picks up dramatically between 10th and 18th weeks
Synapses are formed following the development of which neural structures?
What is a conclusion drawn from The Cat in the Hat studies?
active fetuses become very active infants
Nan is exposed to high levels of radiation during the 6th, 7th, and 8th weeks of gestation. Which of the following organ structures in the fetus are most likely to show abnormalities?
irreversible mental retardation
Your friend is taking Accutane for her adult acne. She comes to you and says that she thinks she is pregnant. What is the best advice that you can give her?
stop taking the medication
What is a true statement about the influence of heroin and methadone upon prenatal and infant development?
60 to 80% are born addicted to these drugs and experience withdrawal symptoms
What best summarizes our understanding of the effects of maternal cocaine use on fetuses and infants?
it is hard to know for sure but it causes disruption of placenta function and premature labor
What does current research say about smoking during pregnancy?
very likely; born lighter; child will be antisocial; developmental problems
Mrs. Smith is receiving information and advice about prenatal care from her health care team. With regard to alcohol, what advice will they most likely give Mrs. Smith?
do not consume alcohol at all
What is a characteristic of a child born with fetal alcohol syndrome?