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Cornell Notes
Topic/Objective:
Name:
Meiosis 11.4
Class/Period:
Date: 02-09-15
Essential Question: How does the reduction division that occurs in Meiosis (including independent assortment
and crossing over) form haploid gametes?
Questions:
Notes:
Mitosis or Meiosis?
 MITOSIS – for use in asexual reproduction (cloning) of non-reproductive cells
 MEIOSIS – for use in sexual reproduction (formation of new organisms) of gametes.
How many sets of genes
 2 – one set from “mom” and the other set from “dad”
Are found in most adult
 These cells are called DIPLOID – means “2 sets”
Organisms?

Homologous chromosomes – each chromosome from “mom” has a matching
Chromosome from “dad”.

Diploid cells have 2 sets of inherited chromosomes and 2 complete sets of genes


Represented as 2N, where N represents the single set found in gametes
Example: Humans are 2N = 46, N = 23 or the number of chromosomes found in
our sperm or our eggs (depending on if you are male or female….)
 Importance – Mitosis makes diploid cells (2N) BUT Meiosis makes HAPLOID cells (1N)
What are haploid cells?
 HAPOLOID cells have a single set of chromosomes, which equals a single set of genes
 In humans, our gametes or haploid cells have 23 chromosomes or N=23.
 Importance: a normal human cell has only 46 chromosomes. 23 from dad, 23 from mom
Summary:
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**MEIOSIS PROCESS ON PAGE 3**
Questions:
Notes:
How do mitosis and
 Replication and Separation of Genetic Material
Meiosis compare?
 Changes in Chromosome Number
 Number of Cell Divisions
How can two alleles from
 Gene Linkage -
Different genes be
Inherited together?
What two conclusions did

Thomas Morgan reach?
What is gene mapping?

Summary:
**MEIOSIS PROCESS ON PAGE 3**
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Mitosis Pic
Mitosis Phase
Mitosis Phase
Description
Meiosis Pic
Meiosis Phase
INTERPHASE
INTERPHASE
PROPHASE
PROPHASE 1
METAPHASE
METAPHASE 1
ANAPHASE
ANAPHASE 1
TELEPHASE
TELEPHASE 1
CYTOKINESIS
CYTOKINESIS
RESULTING
CELLS
RESULTING
CELLS
Interphase for
two daughter
cells & mitosis
will begin
again
PROPHASE 2
NO Interphase
before this
round of
division
METAPHASE 2
ANALPHASE 2
TELEPHASE 2
CYTOKINESIS
RESULTING
CELLS
*DO NOT enter
interphase
again.
Meiosis Phase
Description
2N daughter cells
with different sets
of chromosomes
and alleles.