Describe the three stages of labor
What will be an ideal response?
ANSWER: In the first stage of labor, the contractions push the fetus further against the cervix, dilating
it up to 10 cm in diameter. In response to cervix dilation, stretch receptors in the walls send
nerve signals to the hypothalamus, which responds by stimulating the pituitary to secrete
more oxytocin. In turn, the oxytocin stimulates more forceful contractions of the uterus,
pressing the fetus more strongly against the cervix, and further stretching its walls. The
second stage of labor is the actual birth of the baby. Continued uterine contractions begin
to push the baby through the cervix and the vagina. In the third stage of labor, continuing
contractions of the uterus expel the placenta and any remnants of the umbilical cord and
embryonic membranes as the afterbirth.
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A. is nonpolar. B. has a low heat of vaporization. C. has cohesive properties. D. evaporates and increases body temperature. E. is a relatively poor solvent.
When Louis Kunkel discovered the gene associated with Duchenne's Muscular Dystrophy in the 1980s, he then
needed to determine _____. a. the MIM number of the gene b. whether the gene was linked to blood type c. how the mutant gene produces the disease phenotype d. whether to use positional cloning to clone the gene e. how many copy number variants were present in the gene
When considered as a root cause for cancer, which of the following is linked to at least 17 types of human cancer?
A) eating a high-fat diet B) not exercising regularly C) eating a low-fat diet D) smoking
The greatest extinction event of all time occurred at the end of the:
A) Cambrian period. B) Permian period. C) Mesozoic era. D) Cretaceous period.