Today in Biology
Week #3 Quarter 2 (10/28)
Biology Learning Goal: Overview of
chapter 6 – Genes, DNA,
Chromosomes and chromatids
Warm Up Question: New Warm up
1 what is difference between S and G1
phase?
2.What is a centriole?
3. What is a centromere?
To Do Today:
1. Collect homework
2. Complete mitosis book
3. Quiz
Homework:
None
Fact of the Day
The first Jack
O’Lanterns were
actually made from
turnips.
Halloween is the
second highest
grossing commercial
holiday after
Christmas.
Cell Cycle
Mitosis
Flip
Book
19
Overview of Mitosis
G1-phase
S-phase
Mitosis Begins
Today in Biology
Week #3 Quarter 2 (10/29)
Biology Learning Goal: Overview of
chapter 6 – Genes, DNA,
Chromosomes and chromatids
Warm Up Question:
1. What is purpose of mitosis?
What do you think is purpose of
meiosis?
To Do Today:
1. Video on mitosis and meiosis
2. Homework turned into Mrs. V
3. Read text and answer ?’s
Homework:
None
Fact of the Day
Samhainophobia
is the fear of
Halloween
Boston,
Massachusetts,
holds the record
for the most
Jack O’Lanterns
lit at once
To Do Today
 Watch video on mitosis and
meiosis
 Make sure homework turned in
 Read pgs143-149 answer
questions 1-5 on pg. 149
Today in Biology
Week #3 Quarter 2 (10/30&31)
Biology Learning Goal: Overview of
chapter 6 – Genes, DNA,
Chromosomes and chromatids
Warm Up Question:
1. Cytokinesis begins in which
phase? metaphase, telophase, prophase,
anaphase
2. A cell with 10 chromosomes undergoes
mitosis. How many daughter cells are
created? ___ Each daughter cell has ___
chromosomes. 2, 10 - 10, 2 - 1, 10 - 2, 20
To Do Today:
Mitosis and meiosis notes
and comparison
Homework:
Have a safe
Halloween
Fact of the Day
The word “witch”
comes from the
Old Saxon word
“wica”, meaning
“wise one.” The
earliest witches
were respected
dealers in charms
and medicinal
herbs and tellers
of fortunes.
Mitosis brainpop:
http://www.brainpop.com/science/cellularlifeandgenetics/mitosis/
What stage is this?
What structure is labeled at x?
Mitosis animation:
http://wn.com/Mitosis_Animation#/videos
http://www.bing.com/videos/search?q=mitosis&view=detail&mid=AB67
5AF545E7E8CFB87FAB675AF545E7E8CFB87F&first=41
1
Go to page 10 title
(notebook paper)
3
MEIOSIS I
FOUND ON PAGE 144-145 OF TEXT BOOK
Mitosis and Meiosis comparison:
http://highered.mcgrawhill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120074/bio17.
swf::Comparison of Meiosis and Mitosis
MEIOSIS II
FOUND ON PAGE 144-145
Page 10
Meiosis and Genetic Variation
3 key contributions to genetic variation
1. Crossing over- chromosomes exchange sections
(increases variability)
Meiosis and crossing over
http://www.bing.com/videos/search?q=meiosis+and+crossing+over&view=detail&mid=AA0DF44A352362CA9F94AA0DF
44A352362CA9F94&first=0#view=detail&mid=397D1E7872E2396D6B55397D1E7872E2396D6B55
2. Independent assortment-
Page 10
occurs because there are various ways that
chromosomes may be aligned in metaphase I of
meiosis
http://www.sumanasinc.com/webcontent/animations/content/independe
ntassortment.html
3. Random fertilization
•Any sperm can fuse with any egg.
–A zygote produced by mating of a woman and man
has a unique genetic identity.
–An ovum is one of approximately 8 million possible
chromosome combinations (actually 223).
–The successful sperm represents one of 8 million
different possibilities (actually 223).
–The resulting zygote is composed of 1 in 70 trillion
(223 x 223) possible combinations of chromosomes.
And….
Crossing over adds even more variation to this!
Back pg 10
Meiosis and gamete formation
The main purpose of meiosis is the
formation of gametes-gametogenesis
Meiosis in males:
spermatogenesis- the process of
producing sperm with half the
number of chromosomes (haploid)
as somatic cells.
http://ldysinger.stjohnsem.edu/ThM_599d_Beg/02_Biology/02_spermatoogen.htm
Back
pg 10
How Sperm is made!!
IN MALES, take
one somatic cell
and allow it to go
through two
divisions of
Meiosis I and
Meiosis II and you
will have 4 viable
sperm cells
Back pg
10
Meiosis in
females
oogenesis- the
production of the
egg or ovum in
the female
13
Back
Pg10
How an Egg is made!!
Absorbed back into
body as protein
IN FEMALES,
take one somatic
cell and allow it to
go through two
divisions of
Meiosis I and
Meiosis II and you
will have 1 very
large egg cell
http://ldysinger.stjohnsem.edu/ThM_599d_Beg/0
Mitosis and meiosis
comparison summary
handout
Unit 4
Worksheet 1
Meiosis