Unit 4. Week 1. Mitosis and Meosis Pd. 3

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Warm-up
Answer the questions on your study guide
1. Mark 3 questions that you want to go over
before taking the quiz.
2. Write the equation for photosynthesis and
label the reactants and products.
3. Write the equation for cellular respiration
and label the reactants and products.
(Remember, you must know both equations
by heart for the quiz)
Agenda
Go over Notebook Grades
Pass out Progress Reports
Note card equations??
Go over study guide
Take quiz
Mini Survey
Work on Reading Guide/ Missing Work
Notebook Grades
Notes:
2pts each = 18 pts
Warm-ups: 2pts each = 28 pts
Total points possible = 46 points
Stamps =
Extra Credit points
Overall Grades
If you are missing work on this progress
report, it is due by WEDNESDAY.
All work for this week is due FRIDAY
If you want to improve your grade, you
can retake a test or quiz by coming during
lunch or after school. Plan to go over the
information first.
Mini Survey
Please answer these questions sincerely and hand them
into me before you leave.
1. What is something that we’re doing already that’s
helpful to you? (Notes, Exit Tickets, PowerPoints,
videos, etc.)
2. What are some things that I could do to help you
learn the material better?
3. What are some things YOU could do (individually
or as a class) to help you learn the material?
Warm -Up
Get a textbook and define the following
words in your notes section.
cell cycle, chromosome, chromatid,
diploid, haploid, gamete, mitosis, meiosis,
asexual reproduction, sexual
reproduction, fertilization, zygote
Agenda
Objective: SWBAT: Explain what happens
during the cell cycle and how the nucleus
divides during mitosis AND determine the
number of chromosomes a cell has following
cellular division.
Go over quizzes and grades
Phase Cards
Notes
Mitosis Hand jive
Quiz Grades
1. Do all living things grow and develop?
2. What information does the nucleus
store?
3. What types of cells have a nucleus?
Phase cards
Try to put the cards in order
What are the diagrams on the cards?
How did you decide what order to put
them in?
What do you think is happening at the
end of this process?
Unit 4
Mitosis and Meiosis…
How things grow and develop!
1. How do we grow?
a) The process starts with our cells
Our cells can only grow so big. Then they
have to divide to produce more cells.
Example: When a fetus is developing and
growing, it’s cells are dividing
What happens when a cell gets too
big?
If your mom got pregnant with sextuplets
(meaning 6 babies at once!),the house would
get REALLY crowded. Anyone would have a
hard time taking care of all those kids!
2. What happens when a cell
gets too big?
a. When a cell is small, the information
stored in that DNA is able to meet all of
the cell’s needs.
b. When a cell increases in size, the
DNA has a harder time performing
all of its functions.
3. What are Chromosomes?
a. DNA is bundled up into structures called
chromosomes
b. DNA is a type of nucleic acid that
carries the genetic information and
codes for proteins
DNA controls what a cell does
In Eukaryotic cells, DNA is stored in the nucleus
3. What are chromosomes?
c. Every organism has a certain number of
chromosomes
Example: Humans have 46
chromosomes
d. Most the time, you cannot see chromosomes
because they are spread out in the nucleus
Chromosomes are only visible during
cell division
4. What is the structure of a
chromosome?
a. When they become visible, you can
see that each chromosome is made
up of two identical parts, called
chromatids
Draw & Label the Chromosome
DNA
Chromosome
Chromatid
5. How does a cell divide?
a. Cell Cycle: series of events that a cell
goes through as it grows and divides
b. Interphase is what happens in a cell before it
divides. “Inter” means between, so
interphase means between phases
Step 1: The cell increases in size, makes new
proteins and organelles
Step 2: DNA is synthesized (copied)
Step 3: The cell prepares to divide
5. How does a cell divide?
c. During the “M” phase, two things occur:
Mitosis: the division of a cell’s nucleus
AND
Cytokinesis: the division of a cell
“Cyto” = cell
“kinesis”= movement
d. Body (somatic) cells go through mitosis
and cytokinesis
What are diploid cells?
a. Asexually Reproducing organisms have
diploid cells.
b. A diploid cell is a cell that has two copies
of each chromosome. Diploid means two
sets (2n) of chromosomes.
The Cell Cycle
Mitosis Hand Jive
Draw Mitosis
Mini Survey
Please answer these questions sincerely and hand them
into me before you leave.
1. What is something that we’re doing already that’s
helpful to you? (Notes, Exit Tickets, PowerPoints,
videos, etc.)
2. What are some things that I could do to help you
learn the material better?
3. What are some things YOU could do (individually
or as a class) to help you learn the material?
Warm Up
1.
2.
3.
4.
5.
How do we grow?
What happens in mitosis?
DNA is a type of ________________?
DNA is arranged in ______________.
How many cells are produced after
cytokinesis?
Agenda
Objectives: SWBAT: Explain that meiosis is
necessary for sexual reproduction AND
Determine the number of chromosomes a
cell has following the process of meiosis.
Notes on Meiosis
Demonstration
Draw Meiosis
Video- “Why Sex”
Exit Ticket
Short Quiz on Friday
Practice Problem
If a cell has 10 chromosomes and goes
through mitosis, how many
chromosomes would it’s daughter cell
have?
What type of cells go through mitosis?
How many cells are produced after
cytokinesis?
What is this?
Review of Cell Division
Before a cell becomes too large, it divides to
form two “daughter” cells.
What must a cell do before it can divide?
Copy its DNA!
What divides in the process of mitosis?
The Nucleus
Review of Chromosomes:
a. Each chromosome is a
single, long structure that
only becomes the “x”
shape after DNA
replication.
b. A human has 23 pairs
(46 total) chromosomes
- After DNA is copied,
we have 46 pairs (92
total!) chromosomes!!!!
6. Put these pictures in order
Do all organisms reproduce in the same way?
No
What type of organisms reproduce sexually?
Animals and Plants
What type of organisms reproduce asexually?
Bacteria
What is Asexual Reproduction?
a. When the offspring is identical to its one
parent.
b. What is Mitosis, asexual or sexual
production?
- Asexual. It’s one parent cell producing two
identical cells from itself.
What organisms reproduce
asexually?
c. Most prokaryotes, like bacteria,
reproduce asexually.
d. Asexual reproduction is the primary
form of reproduction for single-celled
organisms such as bacteria.
e. Asexual reproduction produces
diploid cells
What are diploid cells?
a. Asexually Reproducing organisms have
diploid cells.
b. A diploid cell is a cell that has two copies
of each chromosome. Diploid means two
sets (2n) of chromosomes.
What are Haploid Cells?
a. Sex cells (eggs and sperm) contain only
one copy of chromosomes.
b. Haploid cell have only one set of
chromosomes. A haploid cell is a cell that
only has one set (1n) of genes.
c. Eggs have an X chromosome and sperm
cells can have either an X or a Y
chromosome.
Haploid vs. Diploid cells
What is sexual reproduction?
a. Most plants and
animals reproduce by
sexual reproduction.
b. In sexual
reproduction, cells
from two different
parents combine to
form the first cell of
an offspring.
What happens before Sexual
Reproduction?
a. Cellular division happens two times to
produce sex cells.
b. DNA is copied one time, but the total
number of chromosomes is divided two
times.
DEMO!
I need 4 volunteers 
What happens before Sexual
Reproduction?
a. Offspring inherit half of their genetic
information from each parent
b. That means sex cells, or gametes, only
contain half of the parents’ DNA
What is Meiosis?
a. Meiosis is a type of cell division that
results in 4 daughter cells with half the
number of chromosomes.
• Only occurs in organisms that can reproduce
sexually.
• Produces haploid cells
What happens to the # of
chromosomes?
a. In Meiosis, the nucleus divides four
times leaving each nuclei with half the
number of chromosomes.
b. Example:
•
•
•
•
Parent cell- 2n
Replication- 4n or 2 pairs
Mitosis- 2n
Meiosis- n
Draw Meiosis
Life Span of Organism
Warm Up
1. A human gamete has 23 chromosomes.
How many chromosomes does a body cell
have?
2. A ________ cell has two full sets of
chromosomes.
3. Meiosis is necessary for _______________
reproduction.
Agenda
Objectives: SWBAT: Explain that meiosis is
necessary for sexual reproduction AND
Determine the number of chromosomes a
cell has following the process of meiosis.
Video- “Why Sex”
Meiosis and Genetic variability
Exit Ticket
Short Quiz on Friday- Be able to draw
meiosis and mitosis and identify the types
of cells and reproduction
Why Sex DVD
You need to take notes on the video in
your notes section.
Be prepared to share your notes.
Meiosis and Sexual Reproduction
a. Meiosis occurs to make gametes (sex cells)
which combine to create an offspring.
b. Sexual reproduction is what makes
living things different from one another.
The fertilized cell is different from both the
mother's egg and father's sperm because it
has two different sets of DNA.
What is Genetic Variability?
a. Genetic Variability means that
genes are different from each other.
b. Meiosis produces genetic variability
among organisms.
How do we get genetic variation?
Random fertilization of two, unique
cells.
Crossing-over in meiosis
What is crossing-over?
Crossing over is when genes from one
chromosome are exchanged with
genes from another chromosome
results in new combinations of genes
Also called recombination
What are the Advantages of
Meiosis?
a. Sexual reproduction increases the
amount of variation within a species.
b. This variation improves the chance
that a species will adapt to its
environment and be able to survive.
Do Obama’s kids look exactly
like him or Michelle?
Example
The number of owls increase in a park
and the amount of mice decreases
rapidly. However, the quickest mice are
able to escape the owls. In time, more
fast mice are born, allowing them to
survive. They adapted to the change
and survived because they were
genetically different.
What are the Disadvantages
of Mitosis?
a. Organisms that reproduce asexually cannot
develop much variety, because they are just
"copying" the parent.
b. Since they are all exactly the same, the
organisms will probably not survive a
disaster.
Mitosis vs. Meiosis pieces
Each pair will get a sheet of steps in
meiosis as well as mitosis
Cut out the pieces
Organize the pieces into meiosis and
mitosis
Exit Ticket
Exit Ticket
1. Diploid cells have twice as many
chromosomes as ______________ cells
2. Mitosis occurs in Asexual or Sexual
reproduction?
3. If a living thing has 20 chromosomes and it’s
cell goes through meiosis, how many
chromosomes will be in one of the new cells?
4. What is an advantage of meiosis/sexual
reproduction?
Study Guide
Warm-Up
1.
2.
3.
4.
5.
How many cells are produced by Mitosis?
How many cells are produced by Meiosis?
Mitosis is a form of ______________
reproduction
Meiosis is a form of ______________
reproduction
(You do NOT need to copy this question)
If a living thing has 24 chromosomes and its
cell goes through meiosis, how many
chromosomes will be in one of the new cells?
Agenda
White Board Review
Quiz!
Evolution/Planet Earth
White Board Review
How many chromosomes do we have
total?
How many chromosomes did we get from
each parent?
Meiosis produces how many
daughter cells?
4
What type of cells go through
mitosis?
What process produces cells
that are identical to the parent
cell?
Which type of cellular division
allows for genetic variability,
mitosis OR meiosis
Meiosis
A dog has 78 chromosomes in
each of its cells. One of its cells
goes through mitosis. How many
chromosomes will the new,
daughter cell have?
78!!!
Remember, a cell that has gone through
mitosis will have the same number of
chromosomes!
What type of cells has two
sets of chromosomes (2n) ?
Diploid
Sex cells are a type of
___________ cell because
they have half the number of
chromosomes
haploid
A cell in an ovary goes
through meiosis. It started
with 16 chromosomes. How
many will the cell have after
meiosis?
This is a picture of which
process?
Write out
the correct
order of the
pictures
3, 2, 5, 1, 4
LAST Question
What occurs AFTER mitosis in
the Cell Cycle?
Cytokinesis!
Cellular Division Video
Answer the questions as you watch!
What does Meiosis look like?
MEIOSIS I
MEIOSIS II
Possible gametes
Possible gametes
How do we get genetic
variation?
independent assortment of chromosomes
in meiosis.
Chromosomes pair up randomly, and then split
into two new cells
That means two traits can be inherited
independently from one another
Example: a cat's color and tail length
How do we get genetic variation?
random fertilization of gametes (sex
cells)
Any sperm can fertilize any egg
There are trillions of different
combinations of chromosomes
What does Crossing-over look
like?
Crossing over is
important because it
allows for variation
in the genes we
inherit from our
parents.
http://www.goldiesroo
m.org/video_archive
.htm
Crossing over
Compare Mitosis and Meiosis
Diagrams
Brain Pop
http://www.brainpop.com/science/cellul
arlifeandgenetics/genetics/
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