Title: Sex Cell Production
1Sex Cell Production
2Sex cells Gametes
Egg cell Sperm cell
Where have they been mentioned before?
3By the end of this you should know..
- What occurs during each stage of meiosis
- The difference between meiosis and mitosis
4Answer me this.
- How many chromosomes do you have?
- How many chromosomes do your parents have?
- How many chromosomes do the egg cell and the
sperm cell have? - How did they form?
5 Terms to know
- Homologous chromosomes - the male AND female
parent chromosomes containing the same
information found in diploid cells - Which set of information is expressed in you? Mom
or Dad?
Diploid cells - 2N
6Are gametes diploid too?
- Haploid - contain a single set of information (N)
?
Gamete containing information from one parent
7How do we know this?
8And before that???
- The father of genetics, Gregor Mendel used pea
plants to show us the same basic ideas that
technology has proved to us today
9Mendel Vocab you need to know
- Traits a characteristic that is determined by
your genetic information - Genes sections of DNA that determine your
traits - Alleles the different versions of a gene
10Mendel Vocab you need to know
Gene that determines eye color is found here on
your chromosome
11Now that you are an expert on genetic vocabulary
- Lets talk meiosis!!!!!!!!!!!!
12How does the process of meiosis produce haploid
sex cells?
- 2 Divisions are involved
- Meiosis I - the chromosomes are replicated
homologous chromosomes separated into different
cells - Meiosis II - the sister chromatids are
separated from each other
13It looks like this
14Meiosis I
Prophase I Metaphase I Anaphase I Telophase
I Cytokinesis
makes sex cells unique
15In Prophase I..
- Tetrads line up - chromosomes from mom and dad
containing the same information (homologous
pairs) contains 4 chromosomes
16What happens then?
- Crossing over occurs - portions of homologous
chromosomes are exchanged resulting in a new
combination of alleles
17And during Metaphase I???
- Independent Assortment - tetrads can line up in
many different ways allowing for many different
combinations of the parents traits to form in the
sex cells
18Independent Assortment
19Meiosis I Review
- Are homologues present at the end?
- Do the cells contain one set or two sets (one
from Mom one from Dad) of chromosomes at the
end? - So are they haploid or diploid?
20Meiosis II
No INTERPHASE!!! Prophase II Metaphase
II Anaphase II Telophase II Cytokinesis
What other process does this look like?
21Meiosis II Review
- What happened to the sister chromatids?
- Are the end cells haploid or diploid?
- Remind me..why are they called unique?
22Check these out.
- http//www.cellsalive.com/meiosis.htm
- http//highered.mcgraw-hill.com/sites/0072495855/s
tudent_view0/chapter28/animation__how_meiosis_work
s.html
23Any differences? Egg vs. Sperm?
24Meiosis Review
- How many daughter cells are produced?
- Are they identical to the parents? Why or why
not? - Are the haploid or diploid?
- Start your meiosis coloring
25Classwork/Homework Meiosis Coloring
- You will design a meiosis coloring sheet to use
as a study guide - Diploid cells (2n) have green cell membranes
haploid cells (n) have purple cell membranes - One Side Interphase Meiosis I
- Divide into 6 boxes (use one box as a key with
color codes) - Use pencil first and then color in
- Draw 3 homologous pairs (red for maternal
chromosomes and blue for paternal chromosomes) - Label homologous chromosomes, tetrads, crossing
over, independent assortment, centrioles, spindle
fibers, nucleus, sister chromatids
26Classwork/Homework Meiosis Coloring
- Backside Meiosis II
- Divide onto 4 boxes
- Use pencil first and then color in
- Keep the previous chromosome color and number
- Label centrioles, spindle fibers, nucleus,
sister chromatids, chromosomes - If complete, they can be used for your meiosis
quiz on _______________.