Direct instruction
Teacher(s):
Subject:
Angela Arredondo, Madison Frederick, Ulises Aragon
Biology- Molecular Basis of Heredity
Standard(s):

S4C2 PO 3. Explain how genotypic variation occurs and results in phenotypic diversity.
Objectives (Explicit):

Students will demonstrate analysis of Mendelian genetics by completing a Punnett square activity.
Evidence of Mastery (Measurable):
Students will be given a five question quiz the following day containing questions about genotypic variation
and phenotypic diversity. The quiz will be comprised of two multiple choice questions, two fill in the blank
questions and two Punnett squares they have to complete. This quiz will be graded using an answer key.
Sub-objectives, SWBAT (Sequenced from basic to complex):



SWBAT identify the genotypes of the individuals being crossed in the Punnett square from a word
problem.
SWBAT correctly fill out the Punnett square with the genotypes.
SWBAT analyze the ratio of phenotypes that may be expressed in the offspring from the cross.
Key vocabulary:
Materials/Technology Resources to be Used:
Genotype, Phenotype, Recessive trait, Dominant trait,
Allele, Gene, Homozygous, Heterozygous
Worksheet, Power point, Smart board
Opening (state objectives, connect to previous learning, and make RELEVENT to real life)
The instructor will ask an introductory question concerning why some of the physical traits of the students, such
as eye color, earlobe, or cleft chin, appear in some students but not in others.
Teacher Will:
Instructional Input

Present a quick review power point that
gives background information on Mendelian
genetics and examples of how to work
through a Punnett square problem.
Student Will:

Follow along with the power point and
take notes on the steps involved in
completing a Punnett square.
Co-Teaching Strategy/Differentiation:

For ELL and SPED students: Teacher will give a copy of the power point to make it easier for
them to follow along and grasp necessary information to complete the assignment.

For gifted students: Teacher will provide a dihybrid Punnett square for individuals who finish
early or may need a challenge.
Teacher Will:
Guided Practice

Teacher will be working through problems
with the class on the board and then walking
around observing the students while
answering and asking questions regarding
the power point and or worksheet.
Student Will:

Students will be participating by working
through the Punnett squares with the
teacher and then completing questions on
the worksheet in groups of 2-3.
Co-Teaching Strategy/Differentiation:
As a part of the independent practice students will be asked to write out the steps of how to complete a
Punnett square word problem. A short rubric will be required so that the students are aware of what is
expected to be included in the paragraph(s).
Teacher Will:
Independent Practice

Walking around the classroom to answer any
individual questions from the students
regarding the power point, Punnett square
worksheet or individual paragraph
assignment.
Student Will:

Individually working on writing out the
steps, in their own words, of how to
complete a Punnett square word problem.
Co-Teaching Strategy/Differentiation:

ELL and SPED students: A different Punnett square worksheet will be provided for these students
for guided practice that visually shows the characteristics of the traits in each square. (eye color,
hair color, etc.)

Gifted students: A dihybrid Punnett square that contains two traits will be provided.
Closing/Student Reflection/Real-life connections:
Students will make the connection between how and why they look the way they do. They will also become
aware of the difference between a dominant and recessive trait and how they affect one another through alleles.