4. Quiz 1: Nature of Science
ASSIGNMENTS
Assignment
Attempt 1 of 40
COURSES
SECTION 1071
QUESTION 5 of 10
Suppose an experiment is designed to test the durability of batteries in different conditions. All of the batteries tested
are double-A (AA) Brand X. All sets of batteries are preconditioned in different environmental conditions for exactly 168
hours (1 week).
Set 1: 0°C (freezing point of water)
Set 2: 24°C (approximately room temperature)
Set 3:37°C (approximately body temperature)
The batteries are then continuously used to power identical mechanical drummer toys. As long as the toy keeps
drumming the battery is considered functional. The drumming time for each toy is measured as an indication of battery
durability.
In this experiment, which condition is not controlled?
temperature
brand of batteries
test for durability
type of battery (battery size)

the index of refraction of the second medium is higher. i just took the test trust me !

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!