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Unit 9: The Cell Cycle

Name: _________________________________

Period: __________

Test Date: _______________________

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Table of Contents

Title of Page Page Number

Teacher Stamp

Unit 9 Warm-Ups 3-4

Cell Cycle/Interphase Notes 5

DNA Replication Video 6

Cancer Notes 15-16

DNA Replication Notes 7-9

DNA Replication Practice 10-11

Mitosis Notes 12-14

Mitosis Practice 1 14-15

Cell Cycle and Mitosis Practice 2 15-18

Cancer Notes 19-20

Cancer – Cell Cycle Gone Wrong

Practice 21-24

Unit 9 Vocabulary 25

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UNIT 9 WARM-UPS

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Cell Cycle – Interphase Notes

Today we’re going to talk about…

What is the Cell Cycle?

___________________________________________________________________

_____

The Cell Cycle

______% of cell’s time spent in three stages that are collectively called

______________

During Interphase, cells:

G1 phase

Cell grows rapidly while carrying out routine functions

S phase (DNA Synthesis)

The cell’s DNA is ____________________ during this phase –

______________________

G2 phase

Preparation for _________________________

DNA checked for ____________________

After G1, S, and G2 Phases…

The cell would begin Mitosis (M Phase)

• Mitosis is cell division.

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DNA Replication Narration

Watch the video “DNA replication animation by interact Medical” by Steve Colucci on

YouTube to complete the narration:

http://www.youtube.com/watch?v=zdDkiRw1PdU&feature=related&safety_mode=true

&persist_safety_mode=1&safe=active

DNA Replication Video:

Complete the narration to the video (sound on) using the correct vocabulary

words.

DNA _______________________________ is defined by the process by

which an organism’s original ____________________ is used as a

________________________ for the production of a new,

_________________________________________ DNA strand.

Steps of DNA Replication:

i. _____________________ unwinds the original DNA’s

________________ _________________ and creates a replication

fork.

ii. An _________________ called DNA Polymerase 3 works down the

leading strand and up the lagging strand of the replication fork,

synthesizing _________ new strands of __________ by taking free

nucleotides and pairing them up with complimentary bases on the

original DNA _______________________.

DNA Replication is described as ____________________________ because

the two copies of DNA produced each contain ____________ strand of the

_________________ DNA and one entirely __________ DNA strand.

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DNA REPLICATION Notes

DNA Hierarchy

_________________________

__________________________

__________________________

Why does DNA need to replicate?

______________________________________

______________________________________

______________________________________

Let’s quickly review DNA structure in prokaryotes and eukaryotes.

Prokaryotes Eukaryotes

o ________________

stranded

o Single

_________________

o Found in

________________

o A-T

o C-G

o Double stranded

o ________________ helix

o Found in

________________

o A-T

o C-G

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DNA strands are ________________________.

DNA is read ___________ to ___________.

Strand on the left

5’ ________________________3’

Strand on the right

5’ ________________________ 3’

Replication of DNA

Prokaryotes

Begins at a ____________ point in the

_________________________

Proceeds in __________ directions until the

___________________ chromosome is separated

Eukaryotes

Replication can be occurring at _____________________ of places

along the ___________ DNA strand

DNA REPLICATION OVERVIEW:

I. Double stranded DNA ______________________________.

II. Hydrogen bonds between the nucleotides are broken and the DNA strands

_____________________________.

III. Free nucleotides are ________________________ to the template strands of DNA.

IV. Two double helixes form.

How does DNA replicate?

What has to happen to the DNA strand first?

Double stranded _____________ must be __________________________!

How does this happen?

______________________ help the double strand _______________

An enzyme called _____________ ____________________ breaks the ____________________

bonds between the strands!

Once strands are separated and unwound, what happens?

DNA _________________________ adds free ____________________ that _____________

_________ to the exposed _____________________ strand (using Base Pairing Rules!!!)

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DNA polymerase binds the free ________________________ to the ______________________ strand.

DNA polymerase also checks for errors.

It can only _____________ nucleotides if the previous

nucleotide is ________________ paired.

If there is an ____________________,

it ____________________________ to make the

correction.

DNA Replication is Semi-Conservative

During ____________________________, existing DNA strands serve as ___________________

for new ___________________________________ strands

_____________________ (original) strand present in all _______________________ (new)

strands

Complementary Base Pairing Practice

Parent Strand = 5’ 3’ 5’ 3’

ATGGCGTCAT GCTTAGATTA

Daughter Strand = 3’ 5’ 3’ 5’

__________________ __________________

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DNA Replication Practice

The double helix of DNA unwinds and each side serves as a pattern to make a new molecule.

DNA Replication

DNA carries the information for making all of the cell's proteins. These proteins implement all of the

functions of a living organism and determine the organism's characteristics. When the cell reproduces, it

has to pass all of this information on to the daughter cells.

Before a cell can reproduce, it must first replicate, or make a copy of, its DNA. Where DNA replication occurs

depends upon whether the cells is a prokaryote or a eukaryote (see the RNA sidebar on the previous page for

more about the types of cells). DNA replication occurs in the cytoplasm of prokaryotes and in the nucleus of

eukaryotes. Regardless of where DNA replication occurs, the basic process is the same.

DNA Replication is a process that must be done exactly. When it is not completed correctly, mutations

(mistakes) then result. In order to make sure that everything is replicated correctly, you will want to make sure

that you use the proper base pairing rules: A will bond with T only, and G will bond with C only.

Directions:

For each strand of DNA, show the three steps to demonstrate that you could “replicate” the DNA correctly. See

the example for details if you don’t recall how.

Example:

TCCTG ACCCC GCCGG GATAT CCTTC TACCT CCAAA TGTAT

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Cell Cycle – Mitosis Notes

The 4 stages of Mitosis:

P

M

A

T

Mitosis: Duplicated Chromosomes separate into two nuclei

1. ___________________ - the first phase of mitosis

● Chromatin (genetic material) ______________ to form a chromosome.

● Nucleus begins to _____________.

● _______________ begin to move to opposite ends.

● The ________________ begins to form between the centrioles.

2. Metaphase

● Chromosomes become _______________ to the spindle fibers by their centromeres.

● The chromosomes begin to line up in the_________________of the spindle with each

chromatid attached to a separate spindle fiber by its centromere.

● M______________________= M_________________________

Metaphase

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3. Anaphase

● Chromosome copies are _______________ ________________ by microtubules.

● Chromatids move to opposite ___________ of the cell.

● Each chromatid is now a separate _________________.

● A________________= A_________________.

Anaphase

4. Telophase

● _______________ are pulled to opposite poles

● _______________ begins to form around the chromosomes

● _______________ daughter cells are formed.

Telophase

Cytokinesis

● After mitosis, two _____________ are formed

● ____________ __________ grows to enclose each cell

● Forming two genetically _________________ cells

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Results of Mitosis

Mitosis guarantees genetic continuity by the production of _______ _______ ___________________ ________.

The new cells carry out the same cellular processes and functions as those of the parent cell.

Mitosis Animation

Control of the Cell Cycle

Cells have “red light-green light”

__________________________ that turn cell division on and off…

These switches are called “checkpoints”

G1 Checkpoint- Is the cell ______________________

enough and large enough for division?

G2 Checkpoint- Checks DNA replication for

___________________ and repairs occur if necessary.

Mitosis Checkpoint- triggers _____________ from

mitosis and beginning of G1 phase.

CYCLINS

__________________ that regulate the timing of the cell cycle

in eukaryotic cells.

Mitosis Practice 1

The diagram below shows six cells in various phases of the cell cycle. Note the cells are not arranged in

the order in which mitosis occurs and one of the phases of mitosis occurs twice. Use the diagram to

answer questions 1-7.

1) Cells A and F show an early and a late stage of the same phase of mitosis. What phase is it?

2) What structure is breaking down during A & F?

3) Which cell is in anaphase?

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3) Which cell is in the first phase of mitosis?

4) In cell A, what structure is labeled X?

5) Cell C is in what phase of mitosis?

6) Place the diagrams in order from first to last.

8) What is the longest phase of the cell cycle?

9) Why is mitosis important?

Cell Cycle and Mitosis Practice 2

Label the parts of the cell cycle diagram and

briefly describe what is happening:

A

B

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C

D

E

F

G

H

I

J

The Cell Cycle (Phases are in order)

Interphase Prophase Metaphase Anaphase Telophase Interphase

1. Chromosomes move to the middle of the cell during what phase?

2. What are sister chromatids?

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3. What holds the chromatids together?

4. When do the sister chromatids separate?

5. During which phase do chromosomes first become visible?

6. During which phase does the cleavage furrow start forming?

Complete the table by checking the correct column for each statement.

Statement Interphase Mitosis

7. Cell growth occurs

8. Nuclear division occurs

9. Chromosomes are finishing moving into separate daughter cells.

10. Protein production is high

11. Chromosomes are duplicated

12. DNA synthesis occurs

13. Cytoplasm divides immediately after this period

14. Mitochondria and other organelles are made.

The Animal Cell Cycle – Phases are out of order for questions 15 - 23

15. Which cell is in metaphase?

16. Cells A and F show an early and late stage of the same phase of mitosis. What phase is it?

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17. Which cell is not in a phase of mitosis?

18. A new membrane is forming in B. What is this phase called?

19. Sequence the six diagrams in order from first to last.

20. What is the end product of mitosis?

21. If the original cell has 46 chromosomes, how can each new daughter cell also have 46 chromosomes?

22. What is the main difference between cell division in plants and animals?

23. What is the purpose of mitosis?

A.

B.

C.

D.

E.

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CANCER Notes

When control is lost and there is a

mistake in the cell cycle:

__________________

Cancer is an

_______________________________

dividing of cells

Cancer: A Mistake in the Cell Cycle?

It is believed that cancer is caused by changes

____________________________________________________________ controlling

production of __________________________ involved in the cell cycle.

It can result from…

1. a failure to produce certain _______________________________

2. the ____________________________________________ of enzymes

3. the production of enzymes at the __________________________________

When environmental factors trigger the damaged

genes into action, cancer is expressed.

Cancerous cells affect normal cells by forming masses of

tissue called ____________________.

Tumors deprive normal cells of their nutrients.

In the final stages, cancer cells enter the

___________________________________________

and spread throughout the body, forming new tumors.

Cancer is the

_____________________________________ cause of death in the U.S.

Main killers of cancer in the U.S. are:

_____________________ (men and women)

_______________________(men and women)

_______________________(men and women)

_______________________(only men)

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A ________________________ is any substance, radionuclide, or radiation that is an agent

directly involved in causing cancer.

Some causes of cancer include:

_________________________________________

air and water ______________________________

exposure to _______________________________ from the sun

________________________________________

Some promising cancer research…

We have a ____________________________ in our body called p53 that is known as

the_____________________________________________________________.

_____________________________ detects damage in ___________________ and

commands cell to stop dividing so damage can be repaired

*Almost 50% of human cancers are associated with a mutation in the tumor suppressor gene

p53.

Cancer Prevention: REVIEW Controlling the Cell Cycle

Cells have “red light-green light” switches that turn cell division on and off…

These switches are called “checkpoints”:

o G1 Checkpoint- Is the cell healthy enough and large enough for division?

o G2 Checkpoint- Checks DNA replication for errors and repairs occur if necessary.

o Mitosis Checkpoint- triggers exit from mitosis and beginning of G1 phase.

______________________: Proteins that regulate the timing of the cell cycle in

eukaryotic cells.

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Cancer – Cell Cycle Gone Wrong Practice

What is cancer? o Cancer is the uncontrolled growth and division of cells. Cells will keep growing and

dividing, even if your body does not necessarily need them. This means that there is a malfunction in the body in knowing when to start and stop mitosis. The cell usually spends most of its time in interphase and spends a very small amount of time in actual cell dividing phases. However, cancer cells are in a rapid state of cell division and spend much more time out of interphase.

How Are Cancer Cells Different Than Regular Cells? o Cancer cells behave differently than normal functioning cells. This also means that they

likely have different physical characteristics. Cancer cells often have these traits: They spend less time in interphase – therefore they are dividing more! They have uncontrolled mitosis – the means they do not stop division after a

certain point. They grow faster than normal cells They can break away from groups of cells and travel to other places in the body. They have a different physical structure – often with parts that allow them to grip

and grab onto other cells and tissues

***Examples of different cancer cells – with many gripping structures***

What Are Some Causes of Cancer? o There are many causes of cancer. All of these things increase the likelihood of cells

becoming mutated. Mutated cells may not be normal and develop an incorrect cycle of mitosis. They will then keep reproducing at a high rate, causing the body to put lots of energy into their production and upkeep. All of this energy being devoted to these cancer cells causes other normal cells to suffer and can ultimately lead to death.

o Causes of Cancer (things likely to increase the chance of mutated cells) Chemicals – many chemicals cause mutation, leading to problems with mitosis Ultraviolet (UV) Radiation – When tanning or exposed to the sun, you absorb UV

light. UV light causes DNA to be mutated which can alter the cell mitosis cycle in the future.

Viruses – an example is the HPV virus, which is known to cause cervical cancer in females if they are exposed.

X-rays – they radiate cells, causing mutations Genetics -- some people are born with genes that are more likely to mutate over

time or have cancerous properties. If cancer runs in the family, then you are likely to have a higher risk of getting cancer.

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What Is A Tumor?

o A tumor is a cluster of cells going through uncontrolled mitosis. o You can have two types of tumors:

Benign Tumors – these tumors have cells that do NOT migrate to other parts of the body and do not harm other parts of the body

Malignant Tumors – these tumors have cells that can migrate to other parts of the body, potentially causing the cancer cells to spread in the body

When a tumor or cancer cells have spread from their original source, this is called metastasis.

***This picture gives information on how a general body mole looks different than a skin cancer***

If You Get Cancer, How Can It Be Treated? o Each cancer is different, so treatments may vary from person to person. Additionally, how

advanced the cancer is will impact what type of treatment you get.

o Biopsy First, doctors usually want to analyze the first sign of cancer. This is usually seen as a

tumor. Doctors want to look at the tumor to see if it is cancerous or not. If the tumor is cancerous, doctors then want to know if it is benign or malignant. To determine these things, doctors take a biopsy. In a biopsy, the doctor removes a sample of the cells from the tumor to analyze under a microscope to determine the nature of the cells.

o Radiation Therapy If the tumor is cancerous, you can direct radiation at the tumor. The radiation will kill the

cells in the tumor, causing the tumor to shrink and hopefully die.

o Chemotherapy To kill cancer cells in the body, doctors can inject powerful drugs into the body. This is

usually done as an injection of drugs into the blood. These drugs kill cells quickly and aggressively. These drugs will also kill many normal cells in the body. So, this therapy can make people very weak and frail.

o Surgery Often, the doctors will remove the tumor and attempt to remove the cancer from the

body and reduce the chance of it spreading.

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What Is Cancer? Cancer is when what cell process is uncontrolled?: Normal cells of the body spend most of their time in which phase of mitosis?:

How Are Cancer Cells Different From Regular Cells? List the 5 ways that cancer cells are different than normal cells of the body:

What is one way that cancer cells are physically different than normal cells?

What Are Some Causes of Cancer? How do you end up dying from cancer? Explain how the body loses energy due to cancer in the

space below:

List the different possible causes of cancer given in the reading:

o All of these items increase the likelihood of cells becoming , which means that cells may not repair and follow a proper cell division cycle.

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What is a Tumor? A tumor is defined as a

There are two type of tumor. They are: OR o Name each type of tumor below and state what makes it different than the other type:

o Define what happens if the body is undergoing metastasis:

How is Cancer Treated? In order to determine if a tumor is cancerous, a doctor will take a of it.

Describe in the space below what is done during this procedure and why:

If a tumor is deemed cancerous, then one could do a variety of treatments. For each treatment, state what is done to treat the tumor:

o Surgery –

o Chemotherapy –

o Radiation Treatment –

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Unit 9 Vocabulary

1. Anaphase – third phase of mitosis during which chromatids separate and are pulled to opposite sides of the cell

2. Antiparallel - two molecules that are side by side but run in opposite directions. The two strands of DNA are antiparallel. The head of one strand is always laid against the tail of the other strand of DNA.

3. Cancer – common name for a class of diseases characterized by uncontrolled cell division 4. Checkpoints – “red light-green light” switches that turns the cell cycle on and off to check for errors at

different points in the cell cycle 5. Chromatid – one half of a duplicated chromosome 6. Chromosome – long, continuous thread of DNA that consists of numerous genes and regulatory

information 7. Complementary base pair - either of the nucleotide bases linked by a hydrogen bond on opposite

strands of DNA or double-stranded RNA: guanine is the complementary base of cytosine, and adenine is the complementary base of thymine in DNA and of uracil in RNA.

8. Cyclins – group of proteins that regulate the cell cycle 9. Cytokinesis – process by which the cell cytoplasm divides 10. DNA (deoxyribonucleic acid) - molecule that stores genetic information in all organisms 11. DNA replication – the copying of DNA during cell division 12. Enzyme – protein that catalyzes chemical reactions for organisms 13. Free nucleotides – nucleotides floating in the nucleus that is used to build new strands of DNA during

DNA replication 14. Interphase – first three phases of the cell cycle; 90% of the time is here

a. G1 – first phase of interphase in which the cell grows rapidly while carrying out normal cell functions & replicate organelles

b. S – second phase of mitosis in which DNA is replicated (copied) c. G2 – third phase of mitosis in which the cell prepares for mitosis and DNA is checked for errors

15. Metaphase – second phase of mitosis when spindle fibers align the chromosomes along the cell equator

16. Mitosis – process by which a cell divides its nucleus and contents 17. Prophase – first phase of mitosis when chromatin condenses, the nuclear envelope breaks down, the

nucleolus disappears, and the centrosomes and centrioles migrate to opposite sides of the cell 18. Semiconservative Replication - existing DNA strands serve as templates for new complementary

strands; parent (existing DNA) strands serve as templates for new complementary strands (daughter strands)

19. Spindle fibers – microtubules made of proteins that are responsible for splitting the DNA equally during cell division

20. Telophase – last phase of mitosis when a complete set of identical chromosomes is positioned at each pole of the cell, the nuclear membranes start to form, the chromosomes begin to uncoil, and the spindle fibers disassemble