What cell structures are sometimes found attached to the endoplasmic reticulum

The observations of hooke and van leeuwenhoek documenting the existence of microscopic cells formed the basis of what important theory? a. the cell theory stating that all living things are composed of cellsb. the theory of spontaneous generation, which held that life forms could arise spontaneouslyc. the theory of chemotherapy, or use of antimicrobials to destroy pathogenic organismsd. the germ theory of disease and causative agents

An organism has the following traits multicellular cant photosynthesize has a skull. wht kingdom does this organism most likely belong too?

What maintain homeostasis when a persons internal body temperature is 97.5°f