1. Unit 3 Cells and Photosynthesis Section 5 Meiosis
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2. Cells and Photosynthesis
Vocabulary
Cells
Mitosis
Meiosis
Animal Cells and Structures
Plant Cells and Structures
Photosynthesis
Cellular Respiration

3. Standards
SC.912.L.16.17 Compare and contrast mitosis and meiosis and relate to the processes of sexual and asexual reproduction and their consequences for genetic variation.
SC.912.L.16.Su.6 Recognize that cells reproduce by dividing.
SC.912.L.16.Pa.6 Recognize that living things produce offspring (reproduce).
SC.912.L.16.16 Describe the process of meiosis, including independent assortment and crossing over. Explain how reduction division results in the formation of haploid gametes or spores.
SC.912.L.16.In.7 Recognize that cells reproduce by dividing to produce new cells that are identical (mitosis) or new cells that are different (meiosis).
SC.912.L.18.Pa.3 Identify that food is a source of energy.

4. Essential Questions/Big Ideas
What is meiosis?
What are the different phases?

5. Learn more about Meiosis, click on image…

6. What is meiosis?

7. Meisosis
Meiosis is a process where a single cell divides twice to produce four cells containing half the original amount of genetic information. These cells are our sex cells – sperm in males, eggs in females.

8. Watch as the cell prepares as it does for mitosis before the DNA condenses and matching pairs of chromosomes from the mother and father find each other

9. Stages of Meiosis Meiosis can be divided into eight stages.
These are divided between the first time the cell divides (meiosis I) and the second time it divides (meiosis II)
This Photo by Unknown Author is licensed under CC BY-SA

10. Stages of Meiosis

11. Animation of Meiosis, click image to play…

12. Meiosis I and II Interphase
The DNA in the cell is copied resulting in two identical full sets of chromosomes.
During interphase, microtubules extend from these centrosomes.
Meiosis I and II Interphase

13. Meiosis I and II Prophase
The copied chromosomes condense into X-shaped structures that can be easily seen under a microscope.
The chromosomes pair up so that both copies of chromosome 1 are together, both copies of chromosome 2 are together, and so on.
Prophase I is where crossing over occurs and this the variation of genetic material.
At the end of Prophase the membrane around the nucleus in the cell dissolves away, releasing the chromosomes.

14. Meiosis I and II Metaphase
The chromosome pairs line up next to each other along the center (equator) of the cell.
The meiotic spindle fibers attach to one chromosome of each pair.

15. Meiosis I and II Anaphase
The pair of chromosomes are then pulled apart by the meiotic spindle, which pulls one chromosome to one pole of the cell and the other chromosome to the opposite pole.

16. Meiosis I and II Telophase, cytokinesis
The chromosomes complete their move to the opposite poles of the cell.
A membrane forms around each set of chromosomes to create two new nuclei.

17. Match the image and phase
meiosis I
prophase I
metaphase I
anaphase I
telophase I
meiosis II
metaphase II
prophase II
telophase II
anaphase II

18. Mitosis compared to Meiosis
Click on image to play

19. What have you learned…
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