Meiosis Nature s Design of Genetic Variability
Mitosis vs Meiosis Characteristics!!! Mitosis Meiosis Purpose Location Number of Cells at End Human (start) Human (end) Number of Chromosomes
Homologous Chromosome vs. Sister Chromatids What are homologous chromosomes? of chromosomes that have same of One from the (maternal) and one from the (paternal) Ex. Humans have 23 pairs. Both chromosome 11 from mom and dad have gene for, but can have different of the (normal or sickle shape).
Homologous Chromosome vs. Sister Chromatids **Don t confuse homologous chromosomes with copy of made during interphase Must have the same form
Diploid and Haploid Diploid- having a of each ( sets of ) or cells are diploid (all human cells sperm/egg are diploid) = Diploid Number In humans, 2n = Haploid- having a set of ( set of ) and cells are haploid = Haploid Number In humans, n =
Diploid and Haploid
Chromosome Painting A is an organized of pairs of chromosome Humans have chromosomes pairs of pair of chromosomes
Human Reproduction Meiosis allows to pass on of their chromosomes. In Women: an is formed from the
Human Reproduction Meiosis allows to pass on of their chromosomes. In Men: is formed from the
Steps of Meiosis
Meiosis I Reducing the # of in per Cell first has to double the # of chromosomes in which phase? Enters into Meiosis I is formed Structure that is formed when chromosomes pair with another set of chromosomes Two chromosomes pair up.
Meiosis II After meiosis I there are daughter cells with the number of chromosomes as the cell does not take place again does not take place : chromosomes and nuclear envelope.
Meiosis II : chromosomes in the of the cell : from each other; move to ends of the cell : new daughter cells are formed.
Mistakes During Meiosis The of chromosomes to during and after meiosis. Daughter cells have an number of chromosomes One cell has chromosomes Other cell has.
Mistakes during Meiosis: Nondisjunction
What Disorder is This?
What Disorder is This?
Meiosis Example! (Box = Cell) 1) Interphase (early)! 2) Interphase (end) 3) Prophase I! 2n = 6 4) Metaphase I! * homologous pairs line up next to each other vs. below one another in mitosis 5) Anaphase I! * homologous pairs separate! vs. sister chromatids in! mitosis!!! 6) Telophase I/ Cytokinesis! * 2 new cells that are haploid (n = 3 )vs. 2 new cells diploid in mitosis!
Meiosis Example! (Box = Cell) 7) Prophase II 5) Anaphase I! * chromosomes line up sister chromatids separate (like in anaphase in mitosis) 8) Metaphase II! * chromosomes line up (Just like in Metaphase in Mitosis!) 10) Telophase I/ Cytokinesis! * ends with 4 new cells EACH with HALF CHROMOSOMES as original (n= 3)
Stages of Meiosis Review Meiosis I! DNA up Prophase I Homologous chromosomes occurs Metaphase I line up down the center, across from their pair ( doesn t mater) Anaphase I / Telophase I Chromosomes apart, form daughter cells
Stages of Meiosis Review Meiosis II! Prophase II Chromosomes once again Metaphase II Chromosomes line up in the of their cell Anaphase II The individual are pulled to sides of cell Telophase / cytokinesis new cells are formed 4 or 1 and 3
Review of Meiosis Makes haploid cells Meiosis I: Separate Meiosis II: Separate
What to Know About Meiosis Be able to describe the alignment of chromosomes DNA Vocab Homologous Tetrad Crossing over Sister chromatids
Three Most Important Facts About Meiosis! Your genes become mixed-up ( ) Cells become (contain the normal amount of chromosomes) cell become daughter cells
Why Would It Be Important To Have Your Genes Rearranged? When you shuffle genes it is known as having: Helps with to Helps with change as well Greater of
Advantages of Sexual Reproduction Three Ways Meiosis Creates of
The process of random segregation and assortment of chromosomes Occurs during I of meiosis Results in the production of. Law of Independent Assortment
Occurs during / (Tetrad)_ chromosomes pair up and segments of their material. Crossing Over of chromosomes pair up during - Forms X-structure ( ). Chromatids break into regions and are with one another. Results in combinations of that are different from either. Contributes to.
Fertilization What forms as the result of fertilization? A (fertilized egg). Sperm enters egg and join How does a zygote differ from a sperm or an egg? It is a rather than a cell.
Random Fertilization How does random fertilization lead to diversity?