1--Premature infants born at 24 weeks gestation face a wide spectrum of physiological problems. These problems arise because, prior to the third trimester of pregnancy, fetuses
Question 36 options:
a) depend upon amniotic fluid for nutrients
b) have organs that are underdeveloped
c) depend upon amniotic fluid for oxygen
d) have not yet begun cell specialization
2--Occasionally, a developing embryo becomes implanted outside the uterus, such as in the Fallopian tube, an ovary, the cervix, or another organ in the abdominal cavity. One reason such a pregnancy is unsuccessful is that
Question 58 options:
a) adequate structures do not develop to transfer materials between the maternal and embryonic blood
b) ovarian production of progesterone ceases and the placenta degenerates
c) the outer cells of the embryo attach to the endometrium to form the placenta, which degenerates
d) FSH production ceases and the corpus luteum degenerates
3--Consuming caffeine may protect an individual against Parkinson disease (PD). PD is a neurological disorder resulting from reduced production of dopamine by the substantia nigra, a region of the brain. In an experiment, mice were administered caffeine. The mice were then given Chemical X which destroys the cells in the substantia nigra, causing symptoms similar to individuals with PD. The experimental mice showed smaller reduction in dopamine concentrations compared to a control group that were not given caffeine.
The manipulated variable in the experiment was the
Question 77 options:
a) ingestion of caffeine
b) destruction dopamine-producing cells
c) secretion of dopamine
d) administration of Chemical X