1. Give 2 reasons why cells divide. a. DNA overload – Too many demands on DNA b. Exchanging materials – The bigger the cell, the greater the distance oxygen, nutrients, & waste have to travel for cell to work. oxygen oxygen oxygen Carbon dioxide Carbon dioxide Carbon dioxide 2. How is a cell’s DNA like the books in a library? • DNA is like a book of instructions for a cell. • The bigger the cell, the more demands there will be on the DNA. • The bigger the town/city, the more demands there will be for a library book. Instruction Book 3. As a cell increases in size, which increases more rapidly, its surface area or its volume? • volume 4. Calculate the surface area, volume, and ratio of surface area to volume of an imaginary cubic cell measuring 4 cm on each side. Surface Area = 4 cm x 4 cm x 6 = 96 cm2 Volume = 4 cm x 4 cm x 4 cm = 64 cm3 4 cm SA : V = 96:64 = 3:2 4 cm 4 cm Connecting Concepts. Select 2 cell organelles and describe how their functions might be impaired if the cell were to become too large. • Nucleus wouldn’t be able to control all cell activities if cell got too big. • Ribosomes wouldn’t be able to make enough proteins for cell if cell got too big. • Mitochondria wouldn’t be able to supply enough energy/power for cell if cell got too big. • Endoplasmic reticulum wouldn’t be able to make enough lipids and proteins if cell got to big.