Active transport refers to a substance moving from areas in which it has low concentration to an area with high concentration, one example i guess is endocytosis, "<span>the taking in of matter by a living cell by invagination of its membrane to form a vacuole"</span>
<span>The human tympanic membrane or eardrum is a thin, concave membrane stretched across the inner end of the external auditory canal much like the skin covering the top of a drum. The eardrum marks the border between the outer ear and middle ear. ... The middle ear transmits sound from the outer ear to the inner ear.
Answer would be </span>
<span> tympanic membrane or eardrum</span>
Great Question! Mass is basically how heavy Something is. Most people confuse mass with weight but there very different from each other. Weight is the downward force something has because of gravity. Mass can be measured in a variety of units too. The second part of the question is how it affects density. It affects it because to find the density you need to be able to find the mass since the formula is Mass divided by volume. I hope this helped you understand a little bit more about mass. Have a great day!