Chapter 11 Lesson 1 "Heredity"

Materials:

• Worksheet "Heredity"
• Modeling Mendel's Experiments (Lab)
• Two purple(dark colored) beads and two white (light colored) beads for each student,

Objective:

• Students will describe Mendel's studies of pea plants.
• Students will explain the difference between a dominant gene and a recessive gene.
• Students will draw a Punnett Square.
• Students will explain Mendel's conclusions about heredity.

Anticipatory Set: * Show the students a picture of the teacher when he was in kindergarten. Then show pictures of several other children that are in kindergarten. Have the students guess which child is the teacher's child. Take a pole to see the numbers of students that guess each of the children. Begin a discussion about how they knew which was the teacher's child.

				Here is Mr. Marley

Define Genetics and Heredity.

Teacher Input: * Show the student a pictures of Gregor Mendal, pic1, pic2, and go through the Bio on Page 266 in the left hand margin of the teachers edition. Show the students how Mendal was able to control the pollination of the pea plants. Pea plant pollination. Mendal studied many different aspects of the pea plant but started when he noticed that some plants were tall and some were short. He isolated them and tried to get only tall or only short plants. He figured out that he could do this if he self pollinated the pea plants. He repeated this until he got peas that only grew tall plants or peas that only grew short plants. These were called pure plants. He called those plants the P generation P was for "parent". Then started his crosses. This is how it worked. (Show picture from the book on P267, Mendal's tall vs. short experiment) Explain how the experiment went.

Define P generation (parent), F1 Generation(filial, means son or daughter), F2 Generation.

From his first experiment Mendal could not figure out how come the shortness disappeared entirely. Ask the students if they can figure it out.

Use this picture to remind students that genes exist in pairs. Show the students a picture of a chromosome. The gene pair can be found on a chromosomes which will be covered more in the next lesson. Show the students a picture of a punett Square. Explain that this is the second step that Mendal took in his experiment. The capital letter represents the Dominant Gene and the small letter represents the recessive gene. Define "Dominant" and "recessive". Explain the Punnett Square. Then, show the students his third step. (third step) and explain what is happening in this step. Show the students the comparison between phenotype and genotype.

* Then go back to the punnett square for the third step and have an open question and answer session where the teacher points to a genotype and asks for the phenotype or the genotype.

Independent Practice: * Have the students complete the worksheet "Heredity" for lesson 1 while they read the section for chapter 11, lesson 1.

End of Day 1

Anticipatory Set: Have the students read their sentence pairs from yesterday's worksheet. (recessive gene/dominant gene, P generation/F1 generation, F1 generation/F2 generation, heredity/genes, self-pollination/cross-pollination). Review the slides covering the material from yesterday. Have the students make-up genotypes of letters. Give the students an example such as Bb where B is dominat for brown eyes and b is recessive for blue eyes. The phenotype of this individual is brown eyes.

Teacher Input: * Start with a question, "What did Mendal gain from his experiments?" Have the students give a variety of answers and then call there attention to the other types of experiments Mendal did. He compared round seeds to wrinkled seeds, he compared yellow and green pea pods. What did mendal call the information about traits that parents pass to offspring? What two terms did he develop to expain how one factor may be more powerful than another factor? During sexual reproduction mendal thought that paired factors did what? What is it then that determines the traits or the phenotypes that different individuals have?

Guided Practice:/ Independent Practice: * Have the students go through a model of Mendel's Experiment in which they use beads to represent the gene allels during a cross.

Check for Understanding: Have the students complete the quiz over lesson 1.

Duration:

(2days) 30 minutes + 10-15 for Independent Practice (Could be longer if taken for homework).

Alaska Content Standards Addressed in this lesson:

• SCI A-11 Students will understand that similar features are passed on by genes through reproduction (Heredity).
• SCI A-12 Students will distinguish the patterns of similarity and differences in the living world in order to understand the diversity of life and understand the theories that describe the importance of diversity for species and ecosystems.

• SCI A-15 Students will use science to understand and describe the local environment (Local Knowledge);
• SCI B- 2. Students will design and conduct scientific investigations using appropriate instruments
• SCI B- 3. Students will understand that scientific inquiry often involves different ways of thinking, curiosity, and the exploration of multiple paths.
• SCI B - 5. employ ethical standards, including unbiased data collection and factual reporting of results; and
• SCI B - 6. employ strict adherence to safety procedures in conducting scientific investigations.