How long is the absolute refractory period of a cockroach's leg?

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

Below, the levels of organization in a multicellular organism are shown from least to most complex. which level of organization can be described as several different types of tissues working together to perform a common task?

Which feature of a human community is similar to a niche in a biological community