3. Good morning!  Please get a computer and start logging on, and take out this assignment…..

4. Too far to transport important materials.
1. Identify two problems that growth causes for cells and explain how cell division solves those problems.
Too many demands on DNA
Too far to transport important materials.
Cell division makes smaller cells, each with its own DNA.
oxygen
oxygen
oxygen
Carbon
dioxide
Carbon
dioxide
Carbon
dioxide

5. 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
(DNA)

6. What do cells need DNA for….?
to make proteins
Building materials (muscle, bone, etc.)
Control what goes in and out of cell membranes
Control chemical reactions (enzymes)
Fight infections (antibodies)

7. SAtot = SAT+B + SAR+L + SAF+B
2. If a plant cell is 3 micrometers wide, 5 micrometers long, and 2 micrometers thick, what is its surface area, volume, and surface area to volume ratio? (1 micrometer = 1/1,000,000 m) Show your work!
V = l x w x h
= 5 µm x 3µm x 2µm
= 30 µm3 2 5
SAtot = SAT+B + SAR+L + SAF+B 3
= 2(3 µm x5 µm) + 2(5 µm x 2 µm) + 2(3 µm x2 µm)
= 30 µm µm µm2
= 62 µm2
SA:V = 62:30 = 62:30 = 2:1
30 30

8. SAtot = (SA of 1 side) x no. of sides = (7 µm x7 µm) x 6 = 294 µm2
2. If a plant cell is 7 micrometers wide, 7 micrometers long, and 7 micrometers thick, what is its surface area, volume, and surface area to volume ratio? (1 micrometer = 1/1,000,000 m) Show your work!
V = l x w x h
= 7 µm x 7µm x 7µm
= 343 µm3 7 7
SAtot = (SA of 1 side) x no. of sides 7
= (7 µm x7 µm) x 6
= 294 µm2
SA:V = 294:343 = 0.9:1 = 1:1

9. Cells divide because as they get bigger, their volume increases faster than their surface area…..

10. 3. Explain the roles of mitosis and interphase in the cell cycle.
Mitosis = when body cells divide, making more body cells.
Interphase = when cells grow, make copies of DNA, and get ready for mitosis.

12. 4. What are chromosomes?
Bundles of DNA in nucleus formed before mitosis..

13. 5. Draw a simple diagram showing the four stages of mitosis
5. Draw a simple diagram showing the four stages of mitosis. Label each stage and describe what happens to the chromosomes at each step.
Metaphase: Chromosomes line up across middle.
Prophase: Chromosomes form
Anaphase: Chromosomes pulled apart by spindles.
Telophase:
Cell splitting into 2 cells, each with set of chromosomes.
spindles
Interphase

14. How to memorize mitosis steps:
Prophase-Metaphase-Anaphase-Telophase
Professionals Meet At Ten o’clock
Got a better one?

15. 6. In mitosis, do daughter cells have the same number of chromosomes as the parent cell? Explain why or why not.
Yes.
DNA is copied (replicated) before mitosis, so each daughter cell gets complete set.
Parent cell
Daughter cells

16. Mitosis is how you make more body cells.
Parent cell
Daughter cells
Mitosis = “My toes-ees”. How you make more toe cells, body cells. 

17. 7. How are cancer cells different from normal cells?
Normal cells stop dividing when they come in contact with other cells. Cancer cells don’t.

18. Tumors will keep growing, interfere with organ function.
8. What problems are likely to happen if cancer cells are left untreated?
Tumors will keep growing, interfere with organ function.
Cancer cells will get into blood and spread to other body parts.

19. 9. What are the three most common treatments for cancer?
Surgery
Chemotherapy
Radiation therapy

20. Hard to kill cancer cells without killing normal, healthy cells.
10. Give two reasons why cancer has been such a difficult disease to cure.
Hard to kill cancer cells without killing normal, healthy cells.
Really hard to get rid of it once it spreads.
Many types of cancers with many different causes.
Hard to cure genetic diseases.
Constant exposure to chemicals that can cause cancer.

21. Questions?

22. HW: Study for test tomorrow!