The calcium ion passes easily through the membrane of one cell but cannot cross the
membrane of a second cell. which part of the plasma membrane allows this substance
to cross?
a.) carbohydrate groups on the membrane allow the ions to cross.
b.) the fatty acid tails of the phospholipids allow the ions to cross.
c.) protein channels in the plasma membrane allow the ions to cross.
d.) phosphate groups of the phospholipid bilayer allow the ions to cross.

characterization of nanoparticles is a critical step in nanomaterial production as it provides information of dimension, morphology, surface charge, distribution and degree of surface functionalization.

the food storage products of chrysophytes are oils or the polysaccharide laminarin.   formerly classified as plants, the chrysophytes contain the photosynthetic pigments chlorophyll a and c all but the yellow-green algae also contain the carotenoid pigment fucoxanthin.