The correct answer is tympanometer. A tympanometer is not used to measure hearing, but to rather measure the transmission of energy through the middle ear. In this way, tympanometry is an objective test of the function of the middle-ear. Tympanometry is used alongside other measures to asses hearing, such as pure tone audiometry.
A difference between plant cells and animal cells is that most animal cells are round whereas most plant cells are rectangular. Plant cells have a rigid cell wall that surrounds the cell membrane. Animal cells do not have a cell wall.
Because you would not want to change anything in your experiment you are just changing what you are observing
I’m sure the answer is early ancestor.
