1. CELL GROWTH & DIVISION 10-1
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CELL GROWTH
& DIVISION
10-1
Image by Riedell

2. 2 Reasons why cells divide
1. _____________________ As cell grows bigger demand on DNA “genetic library” becomes too great
Ex: Small town library has 1000 books.
As town grows and more people borrow books, there may be a waiting list to read the most popular titles

3. 2 Reasons why cells divide
2. _____________________ As cell grows bigger demand for transport across membrane is too great

4. Need for these depends on ___________
Ability to transport of oxygen, food, waste across cell membrane depends on _______________
Need for these depends on ___________
As cell grows these DON’T increase at the same rate

5. Ratio of Surface Area to Volume in Cells
Section 10-1
Cell Size
Surface Area (length x width x 6)
Volume
(length x width x height)
Ratio of Surface Area to Volume

6. BIGGER CELLS NEED MORE FOOD and OXYGEN, but CAN’T TRANSPORT
IT FAST ENOUGH or IN BIG
ENOUGH QUANTITIES!

7. mainly by increasing cell number
Image from:
Image by Riedell
Multicellular organisms grow
mainly by increasing cell number

8. DNA CAN BE: SPREAD OUT IN NON-DIVIDING CELLS SCRUNCHED UP
IN DIVIDING CELLS

9. DNA in PROKARYOTES BACTERIAL DNA is CIRCULAR HAVE ONE CHROMOSOME
NO NUCLEUS; ATTACHED TO CELL MEMBRANE

10. DNA in EUKARYOTES (Plants & Animals)
DNA is ROD-SHAPED CHROMOSOMES
MANY PAIRS
FOUND IN NUCLEUS

11. Chromosome structure ___________________ 2 identical arms
constricted area holds chromatids together
__________________ PAIR
2 of each chromosome (one from mom; one from dad)