Meiosis

Sexual reproduction occurs only in eukaryotes.

During formation of ________________, the number
of ________________________is reduced by
______________, and returned to the full amount
when the two gametes fuse during fertilization.
o Gametes:

“_________________”is a term referring to the
number of sets of chromosomes.

_______________ and ________________ are terms referring to the
number of sets of chromosomes in a cell.
o Diploid: Organisms are those with ___________ (di) sets of
chromosomes. Human beings (except for their gametes), most
animals and many plants are diploid. We abbreviate diploid as
__________.
o Haploid: organisms/cells have only __________ set of
chromosomes, abbreviated as ______.
o Organisms with more than two sets of chromosomes
are termed ____________________.

Chromosomes that carry the same genes are termed
homologous chromosomes.

Genes:

Alleles:

The alleles on homologous chromosomes
may differ, as in the case of
___________________ individuals. Organisms
(normally) receive one set of homologous
chromosomes from each parent.
o Heterozygous:
o Homozygous:

___________________ is a special type of
nuclear division, which ________________ one copy of each homologous chromosome into each new
"__________________".

Mitosis maintains the cell's ________________
_______________ level (for example, one diploid 2n cell
producing two diploid 2n cells; one haploid n cell producing
two haploid n cells; etc.).

Meiosis, on the other hand, reduces the number of sets of
chromosomes by half, so that when gametic recombination
(fertilization) occurs the ploidy of the parents will be
reestablished.

Most cells in the human body are produced by mitosis.

These are the _____________________ cells.

Cells that become gametes are referred to as ____________ __________.

The vast majority of cell divisions in the human body are mitotic, with meiosis being restricted to the
gonads.

Meiosis comprises ____________ successive nuclear divisions with only _________ round of DNA
replication. 
_____________________can be described for
each nuclear division.
MEIOSIS:

Interphase:
First division of meiosis(Meiosis I)

Prophase 1:

Metaphase 1:

Anaphase 1:

Telophase 1:
Second division of meiosis: Gamete formation (Meiosis II)


Prophase 2:

Metaphase 2:

Anaphase 2:

Telophase 2:

____________parent cell produces ___________ daughter cells. Daughter cells have __________
the number of chromosomes found in the original parent cell and with crossing over, are genetically
different.
Meiosis differs from mitosis primarily because there are two cell divisions in meiosis, resulting in cells
with a haploid number of chromosomes.
Meiosis in Females
Meiosis in Males