Introducing
Your new presentation assistant.
Refine, enhance, and tailor your content, source relevant images, and edit visuals quicker than ever before.
Trending searches
32
Cell Division
By the end of class you should...
- understand the steps of meiosis.
- understand how meiosis contributes to genetic variation.
- be able to describe how the process of meiosis controls the number of chromosomes in a gamete.
Bell Ringer
List 3 things you already know about meiosis.
Chromosomes!
Overview
Is it making sense yet?
General Phases
Anaphase
Prophase
Overview
- DNA separates
- DNA condences
- Nucleus breaks down
- Spindle fibers form
One Diploid (2n) Germ Cell
Two Major Purposes
- Produce haploid cells
- Create cells with unique combinations of genetic information.
Meiosis I
Telophase
Metaphase
Two Major Purposes
- Produce haploid cells
- Create cells with unique combinations of genetic information.
Two Haploid (n) Cells
- DNA lines up on the metaphase plate
- DNA migrates to pole
- DNA decondences
Meiosis II
Four Haploid (n) Gametes
Cytokinesis
Cell membrane divides
Chromosome:
- tightly coiled DNA
- Diploid cells have 23 pairs
- Haploid cells have 23
Sister Chromatids:
- replicated chromosomes
- attached together at the centromere
Homologous Pair/Homologues:
- Pairs of replicated chromosomes
How about now?
Review Videos!
Most organisms do not sexually reproduce
3 Ways to make clones:
Parthenogentic Rotifer
Budding Hydra
Sprouting Redwood
Meiosis
Eukaryotic cell division
Stages of Meiosis:
Interphase
No DNA Replication
Mitosis vs. Meiosis
Important
"Crossing Over" & Independent Assortment
Compare and contrast:
- Prophase vs. Prophase I
- Prophase vs. Prophase II
- Metaphase vs. Metaphase I
- Metaphase vs. Metaphase II
- Anaphase vs. Anaphase I
- Anaphase vs. Anaphase II
- Daughter cells of mitosis vs. Daughter cells of meiosis
Crossing Over: Homologous pairs physical connect to each other and exchange DNA during prophase I.
Chiasma: point where homologous pairs connect.
Independent Assortment: chromosomes arrange randomly during metaphase I & II.
Purpose: creates a unique combination of DNA for each gamete.
#BioBreakout
MEIOSIS
n
n
How does meiosis lead to these outcomes?
Why does meiosis look so similar to mitosis?
Meiosis I
Meiosis II
2n