The heart is an example of several similar tissues working together to do a specific job for an organism, which level of organization represents the heart? А cell
B
tissue
C
organ
D
organ system

Aeukaryotic cell must be from a plant if the cell a) a nucleus b) a nuclear envelope c) cytoplasm d) a cell wall

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 .

Why should organisms reproduce more offspring than will survive? select all that apply.