Which is NOT a method of direct cell counting? spectrophotometry

Petroff-Hausser chamber

microscope cell count using fluorescence staining

Coulter counter

viable plate count

Q: a: in sexually reproducing animals, once fertilization of the egg takes place, the exists as a single cell until cell division begins

The blue particles in this image are able to cross the cell membrane through simple diffusion. how will they be transported? outside the cell inside the cell o a. the substances will move directly across the membrane from outside the cell to inside the cell. b. the substances will move through channels in the membrane proteins from outside the cell to inside the cell. o c. the substances will move through channels in the membrane proteins from inside the cell to outside the cell. o d. the substances will move directly across the membrane from inside the cell to outside the cell.

Which example describes a mutualistic relationship between organisms? young wasps prey on caterpillars. crabs eat the remains of dead fish. tapeworms feed on food in the intestines of cats ants protect a tree on which they feed.