Monday 11/9/2015 Agenda: Cell Cycle and Division!
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Transcript of Monday 11/9/2015 Agenda: Cell Cycle and Division!
Monday 11/9/2015Agenda: Cell Cycle and Division!
Activity: Finish Mitosis Packet
Activity: Cell Cycle Quest!!
Homework:
No Homework Tonight!
https://www.youtube.com/watch?v=ZEwddr9ho-4
Tuesday 11/10/2015Agenda: Cell Cycle and Division!
Activity: Meiosis Reading Guide
Homework:
Meiosis Reading Guide due Thursday/Friday 11/12-11/13/2015 for 40 Points
NO SCHOOL ON WEDNESDAY!
Meiosis Reading Guide • You are to annotate each paragraph 4 times
(there are 4 total paragraphs)
• Answer questions 1-18 on the worksheet
• This is due TODAY for 40 Points!!
Thursday/Friday 11/12-11/13/2015
Agenda: Cell Cycle and Division!
Notes: Meiosis and Meiosis Terminology
Activity: Meiosis Foldable
Activity: Amoeba Sisters with Worksheet
Homework:
No Homework!
MEIOSISQ2 WK3 D2
Meiosis
Meiosis is the type of cell division by which germ cells (eggs and sperm) are
produced.
One parent cell produces four daughter cells.
Daughter cells have half the number of chromosomes found in the parent cell
MeiosisDuring meiosis, DNA replicates
once, but the nucleus divides twice.
There are 2 parts to Meiosis:1. Meiosis 12. Meiosis 2
The 4 new daughter cells have variation of the parent DNA; this is genetic variation
Meiosis Terminology• Karyotype: Arranging of chromosomes from largest
to smallest; pairing up the homologous chromosomes• Autosomes: All non-sex chromosomes; (#1-22 for
humans)• Sex Chromosomes: Chromosomes that determine
the sex of an organism (#23 for humans)• Set (n): # of different chromosomes. REMEMBER:
Haploid = 1set, Diploid= 2 sets
Karyotype of a human• Is this person male or
female?
• How many sex chromosomes are present?
• How many autosome chromosomes are present?
• How many homologous pairs of chromosomes are present?
Background on Meiosis• Meiosis involves 2 divisions of the nucleus
• Meiosis 1 & Meiosis 2
Meiosis STARTS with HOMOLOGOUS CHROMOSOMES
Homologous Chromosomes: They are similar in shape, size & genetic content
Meiosis 1: 1st Division of Meiosis• Prophase I: Chromosomes
condense, nuclear envelope breaks, homologous chromosomes pair at ends.
• ***Cross-Over: Part of chromatid on 1 homologous chromosome exchanges with the other chromosome***
DRAW ME THIS IS
GENETIC VARIATION
Meiosis 1: 1st Division of Meiosis• Metaphase I: Homologous chromosomes move to center of the cell by the spindle fibers.
• Anaphase I: Homologous chromosomes separate and move to opposite poles, BUT sister chromatids stay together. A set of chromosomes moves to each pole
• Telophase I: The spindle fibers disappear, cells begin to cleave; still, two sets of chromosomes are at opposite poles
End of Meiosis I
• Once Meiosis I is complete, cytokinesis occurs and the cell splits into 2 haploid cells. These 2 cells enter Meiosis II
Meiosis II• Prophase II: A new spindle forms around the
chromosomes (no longer HOMOLOGOUS CHROMOSOMES)
• Metaphase II: Chromosomes line up at center & spindle fibers attach to centromere
• Anaphase II: Centromeres split, chromatids move to opposite poles of cell
• Telophase II: Nuclear envelope forms around each set of chromosomes & spindles retracts, cell begins cytokinesis
Result of Meiosis II• 4 HAPLOID cells form as a result of Meiosis II
• Haploid = cell containing 1 set of chromosomes
Meiosis II: 2nd division of Meiosis
Prophase II
http://everyschool.org/u/logan/cellreproductionx/rogersa/research/meiosis.html
Metaphase II
http://everyschool.org/u/logan/cellreproductionx/rogersa/research/meiosis.html
Telophase II
http://everyschool.org/u/logan/cellreproductionx/rogersa/research/meiosis.html
Differences in Mitosis & Meiosis
• Mitosis• Asexual• Cell divides once• Two daughter cells form• Genetic informationS is
identical
• Meiosis• Sexual• Cell divides twice• Four haploid daughter cells
form• Genetic information is
different