CHAPTER 12 THE CELL CYCLE

Introduction Reproduction =continuity of life The ability of organisms to reproduce their kind is one characteristic that best distinguishes living things from nonliving matter. The continuity of life from one cell to another is based on the reproduction of cells via cell division. This division process occurs as part of the cell cycle, the life of a cell from its origin in the division of a parent cell until its own division into two.

Calculate the Surface Area:Volume Ratios for the cubes below. (SA:V) SA= l x w x 6 V= l x w x h #1 1cm # 2 2cm #3 (3cm) SA= 6 cm2 V= 1 cm3 SA:V = 6:1 SA= 24 cm2 V= 8 cm3 SA= 54 cm2 V= 27 cm3 SA:V = 3:1 SA:V = 2:1

Does its surface area get greater? Does its volume get greater? Now, assume each CUBE is one CELL… As the “cell” gets larger………… Does its surface area get greater? Does its volume get greater? Does it’s surface area:volume ratio get greater? Does increased size become an advantage to the cell? Why or why not?

In mammals, heat loss through the skin occurs naturally In mammals, heat loss through the skin occurs naturally. Which of the following mammals would lose heat faster………... ….….Why?

Think back to the Elephant and the Mouse……do you want to change your answer? Which animal will lose heat the fastest?

If you said the mouse, you are right!!! The mouse would lose heat faster due to it’s Surface Area:Volume Ratio