James was observing cells under a microscope. he observed some cells which had a layer outside the plasma membrane. what is this layer called?
a. cell membrane
b. cell wall
c. nuclear membrane

Which of the following is not a defining characteristic of plants?

Legumes, a type of plant, require rhizobia, a type of soil bacteria, to survive since these organisms fix nitrogen during photosynthesis. rhizobia use the legumes for food. what would most likely happen to the legume population if rhizobia suddenly became extinct?

Consider this plant cell which organelle is labeled g