Objective: Student will explain the process of meiosis
Engagement: Construct and show students a model of a simple family tree. Ask students to complete a family tree like the one you displayed or to design one of their own. The family tree should trace back to their great grandparents if possible. Once the family tree has been designed ask students to choose one or two of the phenotypes from the previous homework assignment to incorporate into the family tree. Have students include a key to identify the selected trait. Allow several students to display and discuss their work. (20 minutes approximately)
Exploration: Assign students to groups of four for lab activity. ( 25 minutes approximately)
Materials:
Procedure:
1. Gather the appropriate number and color of Skittles and place them in one cup.
2. Label the remaining cups as (cup 1) Grandfather #1, (cup 2) Grandmother #1, (cup 3) Grandfather # 2, (cup 4) Grandmother # 2, (cup 5) Mother, (cup 6) Father, (cup 7) Nicole, (cup 8) Kia, (cup 9) Kevin, (cup 10) Derrick (This should be done by the Materials Manager)
3. Set up a data sheet for your team by drawing a circle to represent each of the family members. (Recorder / Reporter) On the top row label an area for the four grand parents, on the middle row label an area for the parents, and on the bottom row label an area for the children. (This should be similar to the family tree created earlier.)
4. (Principal Investigator) Pull one Skittle from Grandmother 1 and Grandfather 1's cup and place them in the Mother's cup. Repeat this process for Grandmother 2 and Grandfather 2 placing the Skittles in the Father's cup.
5. Record data
6. Without looking pull one Skittle from Mother's cup and one from Father's. Place those Skittles in Nicole's cup and record data.
7. Return the appropriate color Skittles to Mother's and Father's cup.
8. Repeat steps 6 and 7 for Kia, Kevin and Derrick..
(The Maintenance Director is responsible for keeping the group on task as well as clean up.)
Each color skittle represents an inherited gene. Genes determine things such as eye or hair color just to name a couple. Although we inherit many many genes in this activity we will assume that this one gene determines what you look like.
1. Do all of the children look alike? Why or why not?
2. Are there any twins in the family? How do you know?
3. Do any of the look more like their mother? Do any look more like their father? Which ones and why?
4. Why was it necessary to return the Skittles to the parents cup before selecting genes for the next child?
Discuss results at conclusion of activity.
Explanation:
The genes that we inherit are determined during cell division. Up until this point we have examined asexual reproduction. (one parent cell passing copies of its genes to offspring's.) Because we inherit an equal number of genes from our mother and father we must examine sexual reproduction in cells. This process is refereed to as meiosis.
Meiosis occurs only in the sex cells, egg and sperm. The cells still divide as in mitosis but we need genetic information from both the mother and father.
Project transparency 25 from the Science Interactions Course III Transparency Masters Book and discuss with students the stages of meiosis.
Elaboration:
Refer students to page 412, Science Interactions Course III. Have students work in groups to answer questions A-G.
Evaluation:
1. Have students compare meiosis and mitosis. (When you compare you tell how things are alike as well as different)
2. Have students answer questions from worksheet on page 54 found in the Transparency Masters Book, Science Interactions Course III.
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