Name ______________________ Period ____
Meiosis Guided Notes
_____________ _______________ organisms have two types of cells:
1. somatic cells (body cells) - ___________(2n) __________ ____ _____ ________
__________ _____ ________
2. _____________ (_______ _________) - ___________ (n) includes cells that
are responsible for reproduction (sperm, egg)
Meiosis makes gametes by reducing the number of chromosomes in the daughter cells.
It does this by:
__________ ____ _____ _____ _________
______________ ___________
During __________ ________, the
____________ exchange pieces. **Genetic
variation comes from _________
_________**
Meiosis begins with a _________ _______ (____) - a cell that contains two copies of
each chromosome
The daughter cells in meiosis are ___________ (____) - containing only one copy of
each chromosome
n = _________ ___ ____________
Each species has a unique set of
chromosomes.
Examples:
** Humans ___=____, ___=____ **
Cabbage 2n=18, n=9
Chicken 2n=78, n=39
The steps of meiosis in the correct order
Prophase I
●
●
●
Centrioles separate and spindle forms
homologous pairs form tetrad
_______ _______ _______________
Metaphase I
●
●
spindle fibers attach to the centromere of each chromosome
_____________ ________ ______ ___ ___________ ____
________ ___ ____ _____
Anaphase I
●
spindle pulls homologous chromosomes to _________ ______
___ ____ _______
Telophase I &
Cytokinesis
●
●
●
nuclear membranes form
spindle breaks down
______ ________ _____ _____ ________
Prophase II
●
Same as prophase I, ______ ___ ________ ___
______________ _________
Metaphase II
●
Chromosomes line up on the center line of the cell - ______
_____________ _________
Anaphase II
●
___________ ______________ and move to opposite ends of
cell
Telophase II
& Cytokinesis
●
●
nuclear membranes form
___ __________ ___________ _____ ___________, ______
______________ _____ ____ _________ _______
Identify the statements as applying to mitosis, meiosis, or both by placing an x in the correct box.
Comparing Mitosis & Meiosis
Two divisions
Four daughter cells produced
Associated with growth and asexual reproduction
Associated with sexual reproduction
One division
Two daughter cells produced
Involves duplication of chromosomes
Chromosome number is maintained
Chromosome number is halved
Daughter cells are identical to parent cells
Daughter cells are NOT identical to parent cells.
Produced gametes
Process occurs in body cells
Process occurs in reproductive cells
Mitosis
Meiosis