Deep inside muscle cells, tiny little proteins continually move during aerobic exercise requiring energy to sustain movement. This energy mainly comes from all of the following except: carbohydrates

oxygen

proteins

fats

Which of the following represents a difference between viruses and viroids? a) viruses infect many types of cells, whereas viroids infect only prokaryotic cells.b) viruses have capsids composed of protein, whereas viroids have no capsids.c) viruses have genomes composed of rna, whereas viroids have genomes composed of dna.d) viruses cannot pass through plasmodesmata, whereas viroids can.