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Delve into the constraints of cell growth, exploring DNA overload, surface area to volume ratio, and material transportation. Uncover why cells cannot simply increase in size indefinitely, reflecting on genetic implications and cellular functionality. Discover the crucial balance required for efficient cellular processes. Unravel the mysteries of cell size regulation and its impact on organism function.
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Some things to think about: How big can a cell get? Why? Why aren’t organisms just one big cell instead of many smaller cells?
Why cells can’t get too big: • DNA overload • If a cell gets too big, there won’t be enough DNA to give out all of the necessary instructions. • Remember: DNA contains genes that code for proteinsthat give us our traits. • These proteins also include enzymes that regulate all of the reactions in our cells.
Why cells can’t get too big: • Surface area to volume ratio • The “surface area” of a cell is the cell membrane. • This is where materials must enter and exit the cell. • The “volume” of a cell is the cytoplasm and organelles. • This is where chemical reactions occur, such as breaking down glucose for energy (cell respiration!!).
Why cells can’t get too big: • If the surface area is too small compared to the volume, there won’t be enough area for materials to enter or exit. • Think about what would happen during passing time if there was only one way to get out of the commons! • How does this compare to there only being one door to a classroom?
Why cells can’t get too big: • Transporting materials • The nucleus contains the DNA and the instructions for cell processes. • If the cell gets too big, it would take too long for those instructions to reach their destination and the necessary processes wouldn’t be completed in time.
Tonight’s homework: Finish Cell Division Analogies Bring a calculator to class tomorrow if you have one!
Pg. 245 Copy the diagram from your textbook in your notebook.
Pg. 244 Copy the chromosome diagram from your textbook into your notebook. Sister chromatids