Meiosis Review Questions

  1. Draw the overall process of meiosis
  1. What is the purpose of meiosis?
  1. How is meiosis different than fertilization (making a baby)
  1. How many chromosomes are in a sperm or egg cell?
  1. Explain how crossing over happens
  1. Explain how independent assortment happens

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Today we will be modeling meiosis in our classroom. The classroom represents the ovaries or testes where gametes (sex cells) are made. Your desk will represent one cell that is dividing to create gametes. You will be creating 4 chromosomes represented by Xs made out of construction paper. With these 4 Xs you will create 2 homologous pairs. One color will represent DNA from mom and one color will represent DNA from dad.

Pre-Lab: Draw the overall process you will be modeling as Ms. Poole draws it on the board

Meiosis 1Meiosis 2

Procedure

1. Get construction paper of two colors. You will only need one piece of each color. Designate one color for mom and one color for dad.

Color for Mom:______

Color for Dad: ______

2. Cut each construction paper into 2 different size X’s. To create the homologous chromosomes, you need to make two different size X’s. You should have one large X in each color and one small X in each color.

3. Model crossing over using your chromosomes. In the space below, write a brief explanation of how you will show crossing over with your chromosomes (Hint: You may have to use scissors and glue!)

______

4. After you have ‘crossed over’ your chromosomes, your cell is ready to divide. In order for the chromosome number to be correct, you cell must divide twice. Follow the instructions below for what to do in each division.

Meiosis 1: Put your homologous pairs in the middle of the desk. Separate the pairs by moving one x to one side of the desk and the other x to the opposite side.Remember that homologous pairs are chromosomes carrying the same gene (1 from mom and 1 from dad). X’s of the same size represent homologous chromosomes.

Meiosis 2: Now each side of your desk represents a cell. To complete meiosis 2, you must separate the chromosomes even further. Cut each X in half. Move half of one X to one side of the new ‘cell’ and half of one X to other side. Do this for both sides of the desk, meaning both cells.

To check your work, you should have 8 half X’s and 4 total gametes. Place a sheet of white paper under each 2 chromosomes to show that meiosis is complete. You should have 2 half X’s on each sheet of paper, and four sheets of paper. Draw the shape of sperm or an egg around your gametes.

5. Analyze your resulting gametes. Look around the room and see if all the gametes look the same. Record at least 3 observations below.

1-

2-

3-

Analysis Questions.

1. How does crossing over increase genetic variation? Be specific by using the colors of your construction paper in you answer.

2. Did all the gametes in the room look the same? Why not?

3. How did we show independent assortment as a class?

4. What are two ways genetic variation is introduced in meiosis?

5. Why is genetic variation important?

6. What ONE location is meiosis happening in your body right now?