Chapter 11 Flashcards
Sexual Life Cycle is made up of
Meiosis and Fertilization
Dipolid cells have
2 sets of chromosomes
Haploid cells have
1 set of chromosomes
How are diploid cells produced
when the zygote first undergoes mitosis, it produces diploid cells
How are haploid cells produced
when diploid cells undergo meiosis, it produced haploid cells
Meiosis includes _ rounds of division, including ___ _, and ___ _
2, Meiosis 1, Meiosis 2
Synapsis is during ___ _, includes formation of ___ ___
Prophase 1, Synaptonemal Complexes
Formation of Synaptonemal Complexes is also known as ___ or ___
tetrad, or bivalent
Crossing over is also known as the
genetic recombination between sister chromatids
The site of crossing over
Chiasmata
During metaphase I, the paired homologues
move to the
metaphase plate and become
oriented with homologues of each pair
attached to opposite poles of the spindle
In mitosis, homologues behave
independently
During anaphase I, homologues
are pulled to
opposite poles for each pair of chromosomes
In mitosis, sister chromatids are pulled
to opposite poles
Describe Telophase 1
Nuclear envelope re-forms around each daughter nucleus
Meiosis 2 resembles a
mitotic division
Prophase II
nuclear envelopes dissolve and new spindle
apparatus forms
Metaphase II
chromosomes align on metaphase plate
Anaphase II
sister chromatids are separated from each other
Telophase II
nuclear envelope re-forms around 4 sets of
daughter chromosomes; cytokinesis follows
Final result of Meiosis 2
Four cells containing haploid sets of chromosomes
Meiosis is characterized by 4 features
1.Synapsis and crossing over
2.Sister chromatids remain joined at their centromeres throughout
meiosis I
3.Kinetochores of sister chromatids attach to the same pole in
meiosis I
4.DNA replication is suppressed between meiosis I and meiosis II
Nondisjunction
failure of chromosomes to move to opposite
poles during either meiotic division
Aneuploid gametes
gametes with missing or extra
chromosomes
