nstructor’s Name:  Christina Stewart-Jordan

Subject:  Biology I- Genetics

Date:  July 7, 2008

Period:  3rd

Time: 50 Minutes

Objective(s):

TSW distinguish between dominant and recessive alleles by completing an activity sheet (DOK 2, Biology 5.e).

Materials: 

Textbook, 3-ring binder with 5 tabs, pen and/or pencil, loose leaf paper, and colored pencils.

Do Now: 

Define the following terms:  dominant, recessive, & allele

(5 minutes)

Set:

Last week, we finished talking about five technologies used to analyze DNA.

i.  What are the five technologies we discussed?  PCR, RFLP's, gel electrophoresis, probing, & cloning vectors

ii.  These technologies will be on the test this Friday, so if you have any questions about them as you study this week feel free to ask.

Today, we are going to talk about the terms dominant, recessive, and allele and see what they mean in terms of gene expression.  Then, we're going to do a practice activity on the dominant and recessive alleles, so that we can see how the traits we inherit from each of our parents are expressed and how others are not.

(5 minutes)

Procedure: 

1.  Begin teacher-led discussion, reviewing DNA technologies (see above Set).

2.  TTW randomly select students to read Do Now definitions.

3.  TTW put on overhead, explaining definitions homozygous and heterozygous.  (9 minutes)

(Discuss [genotype: the alleles that make up the gene being expressed] and [phenotype: the physical expression of alleles] before second section of activity.)

4.  TTW pass out activity sheets, explain directions, and do one example for each section on the sheet.  (2 minutes/ section:  6 total)

5.  TTW allow about 6 minutes after each section for the students to complete activity sheet.  (20 total)

6.  After each section, TTW prompt the students to each put their examples on the board.

7.  Closure:  TTW create an example for each section and allow the students to respond aloud.

Closure:

Today, we began talking about dominant and recessive alleles and how being homozygous or heterozygous for a particular trait affects how that trait is expressed. 

[Create an example from each section of activity, and allow students to recall aloud.  Have students tell how they know the traits are dominant/ recessive.  Have them state the difference between genotype and phenotype.]   Tomorrow, we will continue our discussion on dominant and recessive alleles.  Class dismissed!

(5 minutes)

Assessment/ Evaluation:

Objectives: 

• TSW distinguish between dominant and recessive alleles by completing an activity sheet (DOK 2, Biology 5.e).

Informal:  The teacher will listen and watch (M) the students recall the homozygous and heterozygous traits on their activity sheet (C).

Formal:  The teacher will grade (M) the students' classwork and tests (Friday), for their demonstration of their knowledge of genetics (C).  TTW record the grades in the grade book (D).