I.
OBJECTIVES
Predict Phenotypic expressions of traits following simple pattern of
Content Standard
inheritance.
A. Calculate the genotypic and phenotypic ratios (Punnett
square method).
Learning B. Calculate the genotypic and phenotypic ratios until F2
Outcomes generation (Punnett square and branch/fork methods).
Learning Code SBLT-IVF-18-LC
Observing
Classifying
Measuring and using numbers
Making inferences
Predicting
Science Interpreting data
Process Skills Defining operationally
Controlling variables
Making hypothesis
Experimenting
Communicating
HEREDITARY: Trait that is passed from generation to next.
DOMINANT: A trait that is always expressed.
RECESSIVE: A trait that is not always expressed.
HOMOZYGOUS: Two the same allele.
HETEROZYGOUS: Two different allele.
Key
GENOTYPE: The genetic appearance (not seen)
Vocabulary
PHENOTYPE: The physical appearance (seen)
PUNNET SQUARE: The model used to determine the phenotype and genotype
possibilities
PROBABILITY: That chance that a trait will be expressed.
II. CONTENT MENDELIAN GENETICS
III. LEARNING
RESOURCES
A. References
1. Teacher’s 225-230
Guide pages
2. Learner’s 329-350
Materials pages
3. Textbook
pages
4. Additional
Materials from
Learning
Resource (LR)
portal
Internet
B. Other Learning
Science Textbook in Science 8 Based on K-12 Curriculum 2015
Resources
Edition
IV. PROCEDURES
A. The teacher will let the students play a guessing-game called
ELICIT 4 PIC 1 WORD about terms in genetics to activate their
attention towards the lesson and to connect previous lesson
(5 Minutes) learned.
SAMPLE:
A. To captures students interest, the teacher will show of images
of people with different traits, and will ask the students why
do people have different traits, some people have brown eyes,
some have black, some people have earlobes attached directly
to their head, while others have earlobes that hang loose.
Some people have can roll their tongue and some could not,
some people have cleft chin some don’t have, some have
dimples others don’t have.
ENGAGE
(10Minutes)
B. The teacher will ask the students:
Where do people get their different traits?
How are traits passed from one generation to the next?
Students will record their initial thoughts in their
Science Notebook with the expectation that they will
revisit these questions at the conclusion of the lesson.
EXPLORE The students will perform an activity called PICTURE PERFECT
(20 minutes)
Procedure:
1. Show a sample of your family Picture
2. List down traits or characteristics that are manifested in your
family.
3. Identify the traits you got from your father and from your
mother.
4. Handouts will be distributed and students will answer the
guide questions.
TRAIT MOTHER FATHER
The teacher will call some students to share their answer in the
class.
The teacher will introduce the concept of PUNNET SQUARE with the
use of a video clip
Punnet Square is a square diagram that is used to predict an
outcome of a particular cross or breeding experiment. It is named after
Reginald C. Punnett, who devised the approach. The diagram is used
by biologists to determine the probability of an offspring having a
EXPLAIN particular genotype. The Punnett square is a tabular summary of
(10 minutes) possible combinations of maternal alleles with paternal alleles.[1]
These tables can be used to examine the genotypical outcome
probabilities of the offspring of a single trait (allele), or when crossing
multiple traits from the parents. The Punnett Square is a visual
representation of Mendelian inheritance. It is important to
understand the terms "heterozygous", "homozygous", "double
heterozygote" (or homozygote), "dominant allele" and "recessive allele"
when using the Punnett square method.
LEARNING STATION
To apply newly learn concept on context, students will be
ELABORATE grouped into 5 groups, each group is assigned in each
(10 minutes) Learning Station, each learning station has a piece of paper
containing a question on determining the phenotypic and
genotypic ratio.
Each group will be given 3 minutes to answer the question on
each learning station. Music will be played throughout the
activity, as soon as the music stops, each group will move to
another station to answer a new question.
The students will use the Punnet Square to pick the desire
genotype and phenotype of an offspring.
STATION 1
One cat carries heterozygous, long-haired traits (Ss), and its mate
carries homozygous short-haired traits (SS). Use a Punnett square
to determine the probability of one of their offspring having long
hair.
STATION 2
One flower is heterozygous red (Rr) and it is crossed with a
homozygous white (rr) plant. Use a Punnett square to determine the
probability of one of their offspring’s having a red color.
STATION 3
One flower is heterozygous red (Rr) and it is crossed with a
homozygous white (rr) plant. Use a Punnett square to determine the
probability of one of their offspring’s having a white color.
STATION 4
In a certain species of plant, the color purple (P) is dominant to the
color white (p). According to the Punnett Square, what is the
probability of an offspring being white?
STATION 5
In a certain species of pine trees, short needles (S) are dominant to
long needles (s). According to the Punnett square, what is the
probability of an offspring having long needles?
Directions: Using a Punnet Square, compute the phenotypic and
genotypic ratio of the possible offspring of the following up to its
second Filial Generation.
1. Cross a homozygous dominant Black bull with a homozygous Red
EVALUATE Cow. BB= black and bb = red
(10 minutes)
2. Cross a Pure tall plant with a short plant. Write down all possible
outcomes of this cross. TT =Tall tt=short
To further apply students understanding about the concept of
genetics the teacher will require the students to make a doll
model showing trait inherited of offspring from its parents.
EXTEND
V. REMARKS
VI. REFLECTION
A. No. of learners who earned 80% in the
evaluation
B. No. of learners who require additional activities
for remediation
C. Did the remedial lessons work? No. of learners
who have caught up with the lesson
D. No. of learners who continue to require
remediation
E. Which of my teaching strategies worked well?
Why did these work?
F. What difficulties did I encounter which my
principal or supervisor can help me solve?
G. What innovation or localized materials did I
use/discover which I wish to share with other
teachers?
Prepared by:
SARAH C. DONASCO
Teacher 1
Checked by:
ERLYN P. BULAWIN
HT-III Science Curriculum
