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Warm-Up 1. Why is it important to wash your hands and
food?
2. Why is the guy in the video gross?
3. Even when you wash your hands, what can the germs (bacteria) that are left keep doing?
4. Do cells have different stages in their lives like humans do? (like baby, teenager, adult, etc.)
5. Why do some bacterial infections take longer to make you sick than other bacterial infections?
Warm-Up 1. Why is it important to wash your hands?
2. Why is the guy in the video gross?
3. Even when you wash your hands, what can the germs (bacteria) that are left keep doing?
https://www.theguardian.com/media/2019/feb/11/germs-are-not-real-fox-news-host-pete-hegseth
We should wash our hands to remove bacteria (germs) and other things that can cause infection or make us sick
He’s disgusting because he doesn’t wash his hands
The bacteria that isn’t removed can still survive and reproduce (make more bacteria), so you need to wash your hands throughout the day, every day.
4. Do cells have different stages in their lives like humans do? (like baby, teenager, adult, etc.)
• Yes, cells have life cycles called the cell cycle with different phases where they grow and divide into new cells
5. Why do some bacterial infections take longer to make you sick than other bacterial infections?
• Not all bacteria divides at the same speed. • E. coli (which can cause diarrhea) can divide in as little as 20
minutes, but M. leprae (which causes leprosy, also called Hansen's disease) takes almost 13 DAYS to divide. That means someone with E. Coli could become sick in a single day, but someone with M. leprae might not show symptoms for 20 years.
E. coli
M. leprae
Make sure you wash your hands!!!
Cell Cycle and Mitosis Introduction
1. What is the definition of “division”?
2. What is the definition of “multiplying”?
3. What do you think “cell division” means?
4. What do you think “cell multiplication” means?
Separating/ dividing into different parts
Increasing in number
Cells splitting in half
Cells increasing in number
5. What do you think happens to the number of your cells when your body is growing (from fetus all the way to adult?
6. What do you think happens with your skin cells after you get a paper cut?
The number of cells increases (they multiply)
Cells reproduce (by dividing) to create new cells to fill in the cut
7. Just like humans have a life cycle, all cells have a life cycle.
A cell’s life cycle is called the cell cycle.
The cell cycle can be divided into different steps (also called phases).
8. Cells spend about 90% of their life in interphase.
9. During interphase the cell grows, eats, produces proteins, and lives its life. Interphase also includes DNA replication so that the cell can divide.
10. Cells spend the last 10% of their time dividing. 11. For most cells, including all prokaryotic cells and somatic (body) cells, they divide by a process called mitosis. Mitosis is an asexual method of reproduction that results in one cell dividing into two cells that are identical to each other.
Mitosis Notes
12. Humans lose a lot of cells every day, so we have to make new ones. How do cells
create new cells?
The cells we have go through a
process called cell division
13. Cells divide (they split in half) and that means they multiply
(increase) in number
14. Why do cells go through cell division?
1. To reproduce (to create more cells)
2. Cells can’t grow too much because:
a. DNA would be overworked in a big cell
b. Not enough surface area to bring food, water and oxygen in while getting rid of waste
15. Before Cell Division • Before cell division can happen, genetic
material has to be copied
– i.e. DNA replication
16. Cell Division
• Prokaryotes – separate cell into two parts
• Eukaryotes – more complicated (2 stages)
1. Mitosis – division of cell nucleus
2. Cytokinesis – division of cytoplasm
17. Mitosis and Cytokinesis = Asexual Reproduction
• 18. Asexual means the cell can reproduce by itself, it doesn’t need a partner.
• 19. The offspring are exact copies of the parent
20. 4 Phases of Mitosis
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
MITOSIS STARTS WITH A DIPLOID CELL!!
21. Results of Mitosis:
• 2 Diploid daughter cells
22. Mitosis Summary • Mitosis is a process that divides one nucleus
and creates two nuclei.
• The two nuclei produced by mitosis are identical to each other. That means that cell division with mitosis creates two identical cells.
• Mitosis starts with 1 diploid cell and creates 2 identical diploid cells.
• There is NO genetic diversity with mitosis.
Fill out the chart on the right side of your paper using the following
slides
Interphase
• Interphase is when the cell is growing, synthesizing (making) proteins, eating, etc.
• The DNA isn’t condensed in chromosomes because it’s being used
Prophase • What happens during this phase?
– Chromatin condenses into chromosomes
– Centrioles separate
– Spindle begins to form
– Nuclear envelope breaks down
Metaphase • Generally lasts only a few minutes
• What happens during Metaphase?
– Sister Chromatids line up across the center of the cell
– Each chromosome is connected to a spindle fiber at its centromere
Anaphase • What happens during Anaphase?
– Sister chromatids separate into individual chromatids and move apart
Telophase
• What happens during Telophase?
–Chromosomes gather at opposite ends of the cell and lose their distinct shapes
– Two new nuclear envelopes form
GIF of the stages of Mitosis
http://amoebasisters.tumblr.com/image/143141371877
Cytokinesis – dividing the cytoplasm
• The cytoplasm is divided up between the two new cells before the cells finish dividing.
Next Steps: • Edpuzzle Video: go to
https://edpuzzle.com/join/wohumof and complete the video activity (the video name is “Mitosis: The Amazing Cell Process that Uses Division to Multiply!”)
• Quizizz Review: go to https://join.quizizz.com and play the “Cell Division Intro” quiz. Game code is 989956.
• Cell Cycle Practice: Answer the questions on the back of this paper using what you’ve learned.
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