Rough Endoplasmic Reticulum: series of connected flattened sacs, part of a continuous membrane organelle within the cytoplasm of eukaryotic cells, that plays a central role in the synthesis of proteins.
Smooth Endoplasmic Reticulum: comprises of a tube-like structure located near the cell periphery. These tubules or tubes sometimes branch forming a network that is reticular in appearance. The network of smooth endoplasmic reticulum allows for an increased surface area to be devoted to storage of key enzymes.
Critical thinking requires scientists to ask questions about information they come across and assess its validity. This facet of critical thinking helps them avoid bias that originates from personal opinion and helps them distinguish information and fact from common belief.
Sound waves need a medium to travel through. That's why you cant hear sound in space. But you can see light in space and the sun heats up our planet, so yes, light doesnt need a medium to travel through.