Although the placenta acts as a filter for many harmful substances, some are able to pass from mother
to embryo. They include
a. alcohol.
b. toxins in cigarette smoke.
c. caffeine.
d. drugs.
e. all of these.
E
You might also like to view...
The number of ATP molecules generated per atom of oxygen that is reduced when electrons are passed from NADH or reduced FAD (FADH) to O2 is called the
A. P/O ratio. B. phosphorylation coefficient. C. utilization ratio. D. energy yield.
Which of the following is necessary for stomach enzyme activation?
a. acetylcholine b. HCl c. CCK d. GIP e. secretin
A change in a regulatory gene
A. can increase or decrease the expression of a structural gene. B. is always beneficial to the organism in which it occurs. C. is what happens in the production of sickle-cell hemoglobin. D. must be dominant to be effective.
According to the redundancy hypothesis, species are redundant if
A. they have an effect on the ecosystem that is disproportionate with their abundance. B. they could be eliminated or replaced by others with no loss of ecosystem function. C. their ecological niche overlaps somewhat with another species. D. they have grown beyond their carrying capacity for a particular ecosystem.