Why does the Rough Endoplasmic Reticulum look 'rough' under a microscope?

Which one of the following functions is not carried out by smooth endoplasmic reticulum?

What does the cell usually use to produce energy?

Which one of the following will be resulted when an animal cell is surrounded by a medium with lower concentration of water?

Which one of the following cell organelles may play a role in expelling excess water and wastes in case of unicellular organisms?

Which of the following are also considered to be the states of matter? (i) Plasma (ii) Platelets (iii) BEC (iv) BHC