1. Meiosis

2. How are these cell parts involved in meiosis?
Chromosomes: structures made of DNA and contain segments called genes.
Spindle fibers: involved in moving chromosomes to the poles of the cell
Nucleus: contains the chromosomes

3. What type of earlobe do you have?
Homologous chromosomes: carry genes for any trait at same location of chromosome.
Though these genes code for earlobe type, they might not code for exact type of earlobe.

4. Chromosomes and Chromosome Number
Haploid and diploid cells
To maintain the same number of chromosomes from generation to generation, organisms produce gametes – sex cells with half the number of chromosomes.
The symbol n can be used to represent the number of chromosomes in a gamete.
A cell with n chromosomes is called a haploid cell.
A cell that contains 2n chromosomes is called a diploid cell.
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Meiosis

5. How does an organism maintain same # of chromosomes throughout each generation?
Organisms produce gametes, also known as your sex cells.
Gametes have only half the number of chromosomes.
N represents the number of chromosomes in a gamete.
A haploid cell = n
A diploid cell = 2n

6. How many cell divisions are in meiosis?
Meiosis: cell division that reduces the # of chromosomes in a cell and produces gametes.
There are two consecutive cell divisions in Meiosis.
Involves, Meiosis I and Meiosis II.

7. Meiosis I Prophase I Pairing of homologous chromosomes occurs.
Each chromosome consists of two sister chromatids.
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Meiosis

8. Meiosis I
Prophase I
As homologous chromosomes condense, they are bound together in a process called synapsis, which allows for crossing over.
Crossing over – chromosomal segments are exchanged between a pair of homologous chromosomes.
Crossing over produces exchange of genetic information.
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Meiosis

9. Mitosis: one cell division that produces identical cells
Meiosis: two cell divisions that produce haploid daughter cells that are not genetically identical.
Meiosis results in genetic variation.
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Meiosis

10. Sexual Reproduction v. Asexual Reproduction
The organism inherits all of its chromosomes from a single parent.
The new individual is genetically identical to its parent.
Sexual reproduction
Rate of beneficial mutations is faster.
Two parents contribute genetic information to produce unique offspring.
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Meiosis