1. Riddle of the day
What kind of room has no windows or doors? A MUSHROOM

3. CELL Growth and division

4. Growth and division Vocab
Cell division
Mitosis
Cytokinesis
Chromatid
Centromere
Interphase
Cell cycle
Prophase
9. Centriole 10. Spindle 11. Metaphase 12. Anaphase 13. Telophase 14. Cyclin 15. Cancer

5. Henrietta Lacks questions
What is cancer?
Why is cancer dangerous?
How did this discovery help with new research?
What do you think about the ethical and moral side of this discovery?
Why are we talking about cancer?

6. Are adult cells bigger than child cells?
-living things grow by producing more cells. -the cells of an adult animal are no larger than those of a young animal, there are just more of them. Why?

7. There are 2 main limiting factors that don’t allow cells to grow too large.
diffusion problems
- the cell has more trouble moving enough nutrients and wastes across the cell membrane.
Food, water, and oxygen enter through the cell membrane. Waste products do the same.
Growing town example (road)

8. 2. DNA overload - the larger a cell becomes, the more demands the cell places on its DNA. Larger cells have more demand on DNA. Growing town example (library)

9. These factors have to do with a cells surface area to volume ratio
These factors have to do with a cells surface area to volume ratio. As cells get bigger, their volume increases faster than the surface area. Cells need to regulate their size so that they avoid these problems.

12. To control size and avoid this problem, cells use cell division
To control size and avoid this problem, cells use cell division. As a cell divides it forms two daughter cells. New cells come from pre-existing cells. Before it divides, the cell copies all of its DNA.

13. Each daughter cell gets the exact same information
Each daughter cell gets the exact same information. Asexual reproduction means the two cells are the exact same. No variation. pros: quicker to produce offspring, less energy used. cons: less genetic variation, decrease in adaptations and advantages for certain individuals.

14. This process happens over and over again in plant and animal cells
This process happens over and over again in plant and animal cells. This is called the CELL CYCLE. Once the two daughter cells are made, they go back through it again. In the cell cycle, the cell grows and prepares for division. The cycle includes division and three stages of INTERPHASE. The part of the cycle that contains division is called M phase, or MITOSIS.

15. 3 Phases of Interphase: -G1 phase: Cell growth -S phase: DNA Replication -G2 phase: Preparation for M phase Example: 23/24 hours are spent in interphase. 1/24 hours are spent in M phase.

18. Riddle of the Day
What moves forwards and backwards but has no legs, it cannot talk, it cannot walk, it doesn't slither or crawl across the floor either. It comes in different shapes, sizes and colours. What is it? A DOOR

19. Are adult cells larger than child cells?
Yes No

20. What are the limiting factors for cell size?
diffusion problems
DNA overload
Water
A and B

21. What are the two main phases of the cell cycle?
Interphase and Prophase
M Phase and Cytokinesis
Interphase and M phase
Interphase and Cytokinesis

22. What happens in G1 phase of Interphase?
DNA replication
The cell grows
The cell prepares for mitosis
The cell divides

23. The M phase contains mitosis and CYTOKINESIS (cell division)
The M phase contains mitosis and CYTOKINESIS (cell division). Mitosis: -Prophase, Metaphase, Anaphase, Telophase Mitosis makes sure every daughter cell has the same information as the parent cell. Evenly divides the chromosomes. *Divides the nucleus.

24. CHROMOSOME: structure that contains DNA and some proteins
CHROMOSOME: structure that contains DNA and some proteins. In mitosis, two SISTER CHROMATIDS (identical chromosomes) are attached by a CENTROMERE. Humans have 46 chromosomes.

26. PROPHASE
INTERPHASE
Spindle forming
centrioles
chromatin
chromosomes (paired chromatids)
Nuclear envelope
METAPHASE
centromere
CYTOKINESIS
spindle
centriole
Individual chromosomes
Nuclear envelope forming
TELOPHASE
ANAPHASE

28. Phases of Mitosis
PROPHASE -The chromosomes condense and become visible. -The SPINDLE starts to form. -In animals cells, the CENTRIOLES go to opposite sides of the nucleus. -Centrioles help in the formation of the spindles, which helps division happen. -Nuclear envelope starts to break down.

30. METAPHASE -The chromosomes line up across the middle
METAPHASE -The chromosomes line up across the middle. -The spindle fibers begin to attach to the centromere.

31. ANAPHASE -The centromeres split the chromosome and the chromatids are pulled towards the centrioles. -Each chromatid will become a chromosome.

32. TELOPHASE -Chromosomes uncoil and disperse at opposite ends of the cell. -Spindles disappear, and two new nuclear envelopes will form.

33. CYTOKINESIS -Division of the cytoplasm -Two new daughter cells are formed. -Each cell has identical chromosomes.

35. Plant cells divide a little differently than animal cells
Plant cells divide a little differently than animal cells. Plant cells don’t have centrioles, so they instead they perform cytokinesis with the formation of a cell plate to divide.

36. Cell division in eukaryotic cells is complicated
Cell division in eukaryotic cells is complicated. Any mistake will be fatal to the daughter cells. DNA must be copied correctly. CYCLINS are proteins that tell the cell when to divide and regulate the cell cycle.

37. CANCER -Disease of the cell cycle -Uncontrolled cell growth -Few cures, radiation and chemo-therapy can kill cancer cells.