All elements are made of "atoms", and an atom is made up from 3 basic particles: Electrons are particles with a negative charge :)
The correct answer is: Sodium and potassium ions move by active transport, and glucose moves by facilitated diffusion.
Because sodium and potassium are moved through cell membrane against their concentration gradients, transport requires energy (ATP), so it is active. <span>Glucose is a polar molecule and because the plasma membrane is impermeable to polar molecules transport of this important nutrient is accomplished by carrier proteins. This process is called facilitated diffusion and it is passive transport (doesn’t require energy).</span>
If it has a cell wall, it most likely is not a eukaryotic, or animal, cell. Plants, bacteria, and fungi, have cell walls however.
Answer:
The answer for writing 421,700 km in scientific notation is A
