"the human body. it is an organism. it is made up of cells, tissues, organs, and organ systems," said ms. garcia to her students. "i can see tissues, my skin! " said allie. "but how do i know i am made of cells too? " the students carried out an experiment to prove to allie that they were indeed made of cells. here is a photo of their lab activity. what did they do?

Which term describes the number of waves that pass a given point in a given time? crest frequency trough wavelength

The vaccine in a flu shot contains weakened flu viruses. how does a flu shot work with the immune system? a. it destroys lymphocytes. b. it destroys macrophages. c. it activates macrophages. d. it activates lymphocytes.

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.