Unit 5b Mitosis & Meiosis

In this unit we will look at how cells replicate to make new cells. This is done when the body is growing, healing, or replacing worn out cells like blood and skin cells. This is also the reason that DNA replicates itself --so that each new cell has an exact copy of the DNA message. The process of the division of the nucleus and the chromosomes inside is called mitosis.

MITOSIS PRACTICE QUIZ: https://www.biologycorner.com/quiz/qz_mitosis.html

A different type of replication is done when we make the cells necessary for sexual reproduction - egg and sperm. These cells can't be identical to the other cells in our body because we take one egg and one sperm and combine them to make one human cell (or zygote). This type of division is called meiosis. (My memory tool is that my parents had to undergo Meiosis in order to make Me.) Once the zygote is formed, it divides to make exact copies over and over again through the division we call mitosis. Eventually these cells differentiate into certain cell types and they are no longer considered "Stem cells." We will learn more about those in this unit as well!

Learning Objective #1 -- Explain the significance and steps of mitosis and how it fits into the cell cycle.

Online onion root tip for practice identifying cells in mitosis: http://www.biology.arizona.edu/cell_bio/activities/cell_cycle/cell_cycle.html

Mitosis & Cell Cycle Learning Objectives in more detail:

• • Describe the events of each phase of the cell cycle G1, S, G2, and M phase.

  • Describe the events of mitosis in greater detail including the stages of mitosis and what major events occur during each stage.

  • The level of detail should include vocabulary such as centrioles, spindle fibers, centromere, chromosome, chromatin, sister chromatid, nuclear envelope, cell membrane, cell wall, cell plate.

  • Give examples of environmental risk factors (UV exposure, smoking, etc.) for cancer and describe what causes cancer at the cellular level (multiple mutations in DNA that control the cell cycle).

  • Describe the limits to cell growth

Amoeba sisters - great level of detail:

Another video: https://www.youtube.com/watch?v=woD6zvp-4E8 (great video - gives a few additional vocab words than we used)

The cell cycle and cancer:

LEARNING OBJECTIVE 2: Compare the purpose, steps, and outcome of meiosis with mitosis.

Meiosis

Get an overview of MEIOSIS here with the Amoeba sisters:

Or if you prefer Bozeman Science:

PRACTICE QUIZ for MEIOSIS: https://www.biologycorner.com/quiz/qz_meiosis.html

(Question 4 is marking the correct answer wrong so if you get an 88% you really got a 100%. It has the correct answer listed in the answer bank but the program must have the wrong letter selected - FYI)

MODELLING MEIOSIS with GUMMY CHROMSOMES! (Photo by Sarah E.)

ADDITIONAL PRACTICE QUIZZES ADDED MARCH 13th:

NOW TAKE THIS PRACTICE QUIZ: http://www.biologycorner.com/quiz/qz_meiosis.html

TRY THIS ONE, two: https://www.khanacademy.org/science/biology/cellular-molecular-biology/meiosis/e/meiosis

Mitosis vs meiosis: http://www.sciencegeek.net/Biology/review/U3Review.htm

Get a more thorough review of meiosis: