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Aim # 49: Why do cells need to divide?

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Presentation on theme: "Aim # 49: Why do cells need to divide?"— Presentation transcript:

1 Aim # 49: Why do cells need to divide?
Date: February 14th, 2017- Happy Valentine’s Day!! Aim # 49: Why do cells need to divide? HW: Daily Review of Class Notes All Labs due Friday Do Now: Quick Write (1 minute) Write down ANYTHING that comes to mind when you hear the terms “Cell Division” Go!

2 Aim #49: Why do cells need to divide?

3 Compare the size of these organisms
Vs. Vs.

4 1) Do these organisms have different size cells?
No, the cells of a large organism are the same size of a small organism. 2) How do organisms get so big? Cell Division

5 3) Why do cells divide rather than grow in size?
XX XX XX XX XX +

6 DNA “Overload” Small Town DNA Library
The larger the cell, the greater the demands on the DNA library. Eventually, the cell’s DNA would no longer be able to serve the increasing needs of the growing cell. City

7 4) Exchange of Materials
What part of the cell is responsible for the exchange of materials in and out of the cell? Cell Membrane The rate at which particles are able to move across the cell membrane depends on the surface area of the cell (the amount of the cell surface exposed to the environment). SA Rate of Exchange

8 5) Surface Area Small particles have a relatively larger surface area than large particles. Why? What will melt first? The smaller chips have more surface area. Vs. Ice Chips Ice Cube Smaller cells have more surface area and can exchange materials across membrane more efficiently.

9 6) What is Cell Division? The process by which a cell divides into
2 new daughter cells.

10 7) What happens to chromosomes before a cell divides?
The chromosomes are replicated before a cell divides.

11 8) What does replicate mean?
Replication is the process by which DNA makes a copy of itself

12 9) Why is it beneficial for daughter cells to be smaller?
Smaller size of daughter cells increases the surface area and increases rate of exchange of materials across the membrane.

13 Chromosomes What are chromosomes made up of? DNA and Protein
The chromosomes are replicated before a cell divides. Centromere Chromatids Chromosome Replication 2 Chromatids + Centromere Chromosome

14 When do cells divide? Organism Growth
Cells at the root tips divide very rapidly

15 When do cells divide? Repair

16 12) What tissues in our body need to undergo a lot of cell division?
Skin Stomach Why? The cells of these tissues are constantly growing or repairing themselves. Bone

17 Let’s Review… What is cell division? When do cells divide?
When does DNA replication occur? Draw a duplicated chromosome and label the CENTROMERE and SISTER CHROMATIDS. Why is it important that cells are small? To increase the ________ of _______________ of materials through the ________ _________ _. Process by which a cell divides into 2 new daughter cells GROWTH & REPAIR BEFORE cell division RATE EXCHANGE CELL MEMBRANE

18 Mitosis Images Chromosomes Spindle Fibers
Mitosis is the process that divides the cell’s nucleus into two, each with a complete set of genetic material from the parent cell.


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