BI-1754

Hormones

Biology · Secondary 4 · Hard · Hormones

A pregnant woman smokes regularly. Nicotine molecules have a diameter of

2.0\times10^{-2}\,\mu\text{m}

. The placenta allows particles up to

0.5\,\mu\text{m}

in diameter to pass into the fetus’s blood. Which statement about nicotine is correct?

Nicotine cannot cross the placenta because it is larger than $0.5\,\mu\text{m}$ .
Nicotine can cross the placenta because it is smaller than $0.5\,\mu\text{m}$ .
Nicotine cannot cross the placenta because it is smaller than $0.5\,\mu\text{m}$ .
Nicotine can cross the placenta because it is larger than $0.5\,\mu\text{m}$ .

Loading problem…