Download Cell Life Cycle and Reproduction_ppt_notes

Cell Life Cycle and Reproduction (Mitosis & Meiosis)
Name__________________________________________ assign.#_ __
Notes
Unit Goals:
•
Describe the phases of the
cycle.
•
Describe the process of
.
–
Describe the functions of mitosis.
Unit Goals:
•
Describe the process of
.
–
Describe the functions of meiosis.
–
Explain the consequences of mistakes.
***Why not just one large cell? Difficult to get ___________________ in and waste out.
S phase- DNA synthesis
The Cell Cycle
•
•
•
•
•
Chromosomes _________________.
Chromosomes are inherited genetic information
Chromosomes are made up of _____________.
Can only be seen when cells are _____________.
Chromosomes ____________
-or copy is made
• The two copies are
-_____________ together at a
point called a _____________.
-are called sister
_____________.
G1
phase
Cell
undergoes
________.
G2 phase
M phase
•
Cell division (Mitosis and cytokinesis)
Two parts:
1. Nuclear division
–
_____________________
2. Cytoplasmic Division
–
_____________________
MITOSIS
•
In eukaryotes, it is the main process by which
____________ and tissue ______________ is
accomplished.
•
Mitosis is also the main process by which single-celled and
many multi-celled eukaryotes reproduce ______________.
Preparation for Mitosis. Organelles are
________________.
G1, S, and G2 are known together as
______________________..
 Gametes are ______ cells.
 Somatic cells are “___________” body cells.
4 Steps of Mitosis (PMAT)
Prophase:
 Chromosomes condense and attach
to the ____________ fibers at
their ________________.
 Nuclear Membrane breaks down.
 Centrioles move to opposite sides
of the cell and organize the
spindle fibers.
Metaphase:
 Chromosomes
________ up in
the __________
of the cell.
Anaphase:
Chromosomes
separate-Move to
____________
sides of the cell
Telophase:
 Nuclear Envelope _________
 There are now TWO nuclei in
one cell!
 …And they contain the
___________ genetic
information *SAME
_____________ OF
CHROMOSOMES
1
Cell Life Cycle and Reproduction (Mitosis & Meiosis)
Name__________________________________________ assign.#_ __
Notes
Cytokinesis:
•
•
•
•
•
_________________ division
Each cell gets __________ of the organelles.
After mitosis: cell _______________ in half to form two new cells.
Animal cells pinch.
Cytokinesis in plant cells is different from that in animal cells.
•
In plant cells a _______ _________ forms from the inside out.
Results of Mitosis & Cytokinesis
•
new cells.
• The new cells- called daughter cells- have the
________ number of chromosomes as the mother cell.
• This occurs in all
cells in your body.
• You have _______chromosomes in all of your somatic
cells-_____ __________!
BOOK WORK: on your own
1.
2.
Cell Cycle Vocabulary
cell division
centromere
3.
interphase
4.
cell cycle
5.
mitosis
6.
prophase
7.
centriole
8.
spindle
9.
metaphase
10.
anaphase
11.
telophase
12.
cytokinesis
13.
cyclin
14.
cancer
15.
meiosis
16.
sister chromatid
2
Cell Life Cycle and Reproduction (Mitosis & Meiosis)
Name__________________________________________ assign.#_ __
Mitosis Review
1. The purpose of mitosis is to ensure that:
each new cell is genetically different from its
parent
6. Most cells spend the majority of their time in:
prophase
metaphase
each new cell receives the proper number of
chromosomes
interphase
gametes are available for reproduction
telophase
DNA is replicated without errors
2. The image below illustrates what phase of mitosis
7. Cytokinesis begins after which phase?
telophase
anaphase
prophase
teleophase
anaphase
metaphase
prophase
3. Which of the following is NOT part of mitosis
prophase
metaphase
telophase
interphase
4. Which of the following is the term used for the
"connector" between two sister chromatids?
metaphase
8. Describe the 2 main purposes of mitosis
__________________________________________
__________________________________________
9. How many times does the cell divide during mitosis?
__________________________________________
10. What kind of cells (somatic or Gametes) are
produced at the end of mitosis?
__________________________________________
chromosome
11. What are sister chromatids? When are they
produced?___________________________________
__________________________________________
chromatid
12. Label the cell to the right:
centromere
spindle fiber
5. A cell that has 20 chromosomes undergoes mitosis.
Which of the following is true?
two daughter cells will be created, each have 20
chromosomes
two daughter cells will be created, each have 40
chromosomes
4 daughter cells will be created, each having 10
chromosomes
2 daughter cells will be created, each having 10
chromosomes
1) Sister Chromatid
2) Spindle Fibers
3) Centromere
4) Centrol
13) Which phase of mitosis is
the cell to the right in?
_______________________
14) If a human skin cell goes through mitosis, how many
chromosomes will the two new daughter cells have?____
15) If an alligator has 12 chromosomes in a somatic cell,
how many will it have after a somatic cell undergoes
mitosis? ____________
3
Cell Life Cycle and Reproduction (Mitosis & Meiosis)
Name__________________________________________ assign.#_ __
Notes
Back to Notes:
Reproduction of Sex Cells



cells- __________and ________
Process is called ____________
Similar to Mitosis


MEIOSIS = CHROMOSOME REDUCTION DIVISION




Cell _________ ____________
First division is like mitosis and then the cell
divides again to create 4 ________ cells.
Diploid
In Humans, starts with ___ and ends up with ____.
Why? Fertilization creates the _________ condition again
Sperm formation- 4 haploid sperm cells are formed.
Egg formation-most of the cytoplasm is used in one cell and
the other three disintegrate. One haploid egg cell is formed.
Crossing Over
• Sometime during
meiosis the
chromosomes
can
___________
information
• Major source of
___________
___________
in species.
Haploid
Prokaryotic Cell Division
• __________
_____________
• DNA is
________ and
then the cell
_________ in
half.
• ____________
__ Reproduction
__________ genetically identical!
Contains _____of the genetic information.
Regulation of the Cell Cycle
• How do cells know when to divide? When to stop dividing?
• _______________-___________ that regulate the cell cycle.
• Unregulated cell growth can form masses of cells called tumors-___________.
•
Mitosis and Meiosis Summary
Read and answer the questions at the end.
Cell division
When a cell divides, its two daughter cells must receive the required number of DNA molecules. In eukaryotes,
DNA is sorted into two nuclei in the process of mitosis. A separate process divides the cytoplasm in two. Mitosis is
the process in which threadlike nuclear material is divided equally between two daughter cells. Mitosis keeps the
number of chromosomes constant from one cell generation to the next. In eukaryotes mitotic cell division is the
main process by which growth and tissue repair is accomplished. Mitosis is also the main process by which singlecelled and many multi-celled eukaryotes reproduce asexually.
Mitosis
Mitosis can be broken into four phases: prophase, metaphase, anaphase, and telophase.
4
Cell Life Cycle and Reproduction (Mitosis & Meiosis)
Name__________________________________________ assign.#_ __
� During prophase, the duplicated chromosomes become distinct and spindle fibers radiate across the cell. The
nuclear envelope starts to break up.
� During metaphase, the duplicated chromosomes line up randomly in the center of the cell between the spindles at
the spindle equator.
� During anaphase, the duplicated chromosomes are pulled to opposite ends of the cell. Every chromosome that was
present in the parent cell is now represented by the daughter chromosome at the poles.
� During telophase, a nuclear membrane forms around the chromosomes at each end of the cell. The spindle fibers
disappear and the chromosomes disperse and become less distinct. Each nucleus has the same chromosome number
as the parent cell. The process of mitosis is now complete.
Cell division produces two new cells, each with the same number of chromosomes as the original cell. These cells are
called diploid cells. In humans, the diploid number is 46. Most of your body cells are produced by cell division and
contain 46 chromosomes or 23 pairs of homologous (similar) chromosomes
Cytokinesis
At the end of telophase, the cytoplasm begins to divide. In animal cells, the plasma membrane forms a groove and
“pinches in” at the middle of the cell. This separates the two new nuclei and splits the cell in half. In plant cells, the
rigid cell wall prevents a groove from forming. Instead, a cell plate forms along the center of the cell and cuts the
cell in half. The cell plate forms new cell walls. Two daughter cells are formed as a result of cytokinesis. They are
identical to their parent cell. Cell division allows unicellular organisms to duplicate themselves in a process called
asexual reproduction. In multi-cellular organisms, cell division allows them to grow (i.e., increase the size of the
organism), develop from a single cell into a multi-cellular organism, and make other cells to repair and replace worn
out cells.
****Questions*****
1. In which phase do the chromosomes line up in the middle?
2. When does the cell actually split?
3. What are the two new cells called?
4. Are the two new cells genetically identical or not?
5. Give 2 reasons why a cell might go through mitosis? (I think this would be a great test question. Don’t you?)
A few cells are produced differently through a process called meiosis. The cells that are produced as a result of
meiosis are called gametes or sex cells. The cell divides two times to form 4 cells.
 The first meiotic division produces two cells containing half the number of doublestranded chromosomes.
 The second meiotic division results in the formation of four cells, each containinghalf the number of
single-stranded chromosomes.
The prefix hap- means “half” so haploid cells contain only one half of each of the pairs of similar chromosomes. In
humans, haploid cells contain 23 chromosomes. These cells are called sperm and egg cells. The following are
overviews of sperm and egg formation.
♂ During sperm formation, each primary sperm cell develops into four haploid cells of equal size. As they mature,
the cells lose most of their cytoplasm and develop a long whip-like tail used in movement.
♀ During egg formation, each primary egg cell that undergoes meiosis develops into one large haploid cell and
three smaller haploid cells called polar bodies. The first meiotic division produces one large cell and the first
polar body. After the second meiotic division, the large cell forms an egg cell and another polar body. The first
polar body may undergo a second meiotic division to produce two more polar bodies. The polar bodies
disintegrate. So what is the advantage of uneven cytokinesis? The final egg cell is provided with a larger supply
of stored nutrients.
****Question*****
1) How is Meiosis different from Mitosis?
5
Cell Life Cycle and Reproduction (Mitosis & Meiosis)
Name__________________________________________ assign.#_ __
Mitosis Lab
Name_________________________________________Assign#_______
I. Prepared Slides with microscopes (glass):
“Onion Root Tip” Mitosis: 
Mag:
Sketch and label at least 2 different cells undergoing Mitosis.
***Give the name of the phase the cells are in.
Animal Cell “Fish Blastula” Mitosis:
Sketch and label at least 2 different cells undergoing Mitosis.
***Give the name of the phase the cells are in.
Mag:
Animal Cell “Uterus” Mitosis:
Mag:
Sketch and label at least 2 different cells undergoing Mitosis.
II. Microslide Viewers:
“Animal Mitosis”
a) Slide #2: Sketch and label the chromosomes.
Phase:__________
b) Slide #3: Sketch and label the chromosomes.
Phase:__________
Mag:
Mag:
c) Slide #6: Sketch and label the chromosomes.
Phase:__________
Mag:
Phase:__________
Mag:
d) Slide #7: Sketch and label the chromosomes.
6
Cell Life Cycle and Reproduction (Mitosis & Meiosis)
Name__________________________________________ assign.#_ __
Post lab questions:
1.
Fill in the vinn diagram by comparing and contrasting mitosis and Meiosis:
2.
Discuss the reasons why cells go through Mitosis?
3.
Discuss the reasons why cells go through Meiosis?
4.
What molecules regulate the cell cycle? What happens when the cell cycle is uncontrolled?
5.
What is nondisjunction? When does it happen? What does it cause?
Cell Cycle Online
1) Why must a cell divide?
a) Why must cells divide?
Click next and watch the cell.
2) Cell Cycle Video
a) What are the 4 parts of the cycle?
Label the circle
b) What happens during each (be brief)?
Add this to the circle. 
c) What controls the cell cycle? What
molecules?
d) What can happen if the cell cycled is
uncontrolled?
3) Mitosis video Clip
a) In mitosis a cell reproduces by
____________ into ____ genetically
___________________ cells.
b) Make a sketch of a cell from each phase. Give the name of the phase:
_______________
________________
________________
_______________
c) Are the cells genetically identical after the split? __________
7
Cell Life Cycle and Reproduction (Mitosis & Meiosis)
Name__________________________________________ assign.#_ __
4) Biology in Motion
Mitosis
a) Click “practice mitosis.” Make the cell go through mitosis.
Draw the final 2 cells .
Meiosis
b) Click “practice meiosis.” Make the cell go through meiosis.
Draw the final 4 cells .
c) How are mitosis and meiosis different?
5) Meiosis Video
a) Meiosis is the process by which a ______ nucleus divides ____ to produce ____ __________ nuclei.
b) What are the products of meiosis in animals?
c) When homologous chromosomes exchange pieces of DNA the process is called ____________________.
d) How is meiosis different from mitosis? _________________________________________________________
_______________________________________________________________________________________
e) What is the end result of meiosis? _____________________________________________________________
6) Mitosis vs. Meiosis
Click through the animation and just watch the cells divide. (You only need to look at the pictures)
1) How are the two processes similar?
2) How are the two processes different?
7) Try the practice quizzes and see how you do 
8) Post activity questions:
1.
What is the cell cycle?
2.
What is mitosis?
3.
What kinds of cells go through mitosis?
4.
Why do cells go through mitosis?
5.
Are the cells diploid or haploid at the beginning of mitosis? At the end?
6.
Are the daughter cells genetically identical after mitosis?
7.
What is meiosis?
8.
What kinds of cells go through meiosis?
9.
Why do cells go through meiosis?
Mitosis
Meiosis
10. Are the cells diploid or haploid at the beginning of meiosis? At the end?
11. Are the daughter cells genetically identical after meiosis?
8