Why are the rhizobium bacteria beneficial to plants?

After getting the slide and microscope ready, stella is eager to see the microscopic pond water specimen! she crouches around her microscope and aligns her eye with the microscope’s eyepiece. but she's only able to see a bright white light. at this point, no specimens or cells are visible on stella's pond water slide. after taking a moment to collect her thoughts, stella realizes she can't see any lifeforms because .

Explain how the number of similarities between the embryos from early stage to late stage is used as evidence of a common ancestry

Wich level of organization includes all the other levels or organizations