Nematocysts are Expelled When

Question

Nematocysts are expelled when
A)the osmotic pressure reaches 140 atmospheres.
B)the hydrostatic pressure exceeds the osmotic pressure.
C)the internal hydrostatic pressure increases when water enters due to osmotic pressure inside.
D)the cnidocil stimulates the cnidocyte to decrease hydrostatic pressure and increase osmotic pressure.

Accepted Answer

Nematocysts are expelled from the cnidocytes when the internal hydrostatic pressure increases due to the entry of water caused by osmotic pressure inside the cnidocyte. This results in the rapid discharge of the nematocyst, leading to the release of toxins or the capture of prey. Option A is incorrect as the osmotic pressure required to expel nematocysts is not a fixed value of 140 atmospheres. Option B and D are incorrect as they do not accurately describe the mechanism of nematocyst expulsion.