A Detailed lesson Plan in Biology for Grade 9
By Mitchelle Dawn E. Paye
I. Objective
At the end of this activity, the students are expected to:
1. Explain the different patterns of non-Mendelian inheritance
II. Subject Matter
A. Topic: Different Patterns of Non-mendelian inheritance
B. Materials:
“find the end” map
Visual Aids
Chalk
C. Ideas
Non-Mendelian Inheritance- do not follow the dominant-recessive traits of Mendel.
-traits can be controlled by more than one gene
-alleles are neither dominant nor recessive
D. Process: Discussion, Activity, Evaluation
E. Values: Passion, Curiosity
III.Procedure
TEACHER’S ACTIVITY
STUDENT’S ACTIVITY
A.P reparatory Activity
1.Prayer
Everyone please stand up, and let us have
our prayer . Ms.
please lead the
Christian prayer and Mr. Baulo for the
Muslim prayer.
•
(Students standing up)
(Students praying.)
Greetings
Good Afternoon class!
Please take your seats.
How are you feeling today?
That’s great!
3.Checking of Attendance
Good afternoon Ma’am!
We’re good Ma’am.
Miss Secretary, who are absent today?
4. Collecting of Assignment
(secretary reporting the absent)
Please pass the assignment that I have
given to you last meeting. Pass it forward
silently in 10seconds(teacher count 10
seconds)
Ok , all papers in?
Yes ma’am!
5. Drill
I have here with me a simple activity before
we start our lesson. It’s like a map
wherein you imagine that you are
strolling outside and all you have to
do is to trace it based on the
instruction there. Now, group
yourselves into four. So, are you
ready? You have 5 minutes to do it.
After 5 min….
Ok time’s up! Did you have fun in the
activity?
What did you observe in the activity?
Very good! Who can add the idea of
Princess?
Yes it has different colors.
•
Review of Past lesson
What was our topic last meeting?
Very good! So can you still
remember what is genotype?
(students group themselves)
Yes Ma’am!
(Some will say yes)
Ma’am there are many animals
and plants.
It has different colors ma’am.
Ma’am our topic last meeting is
about the Mendelian genetics.
How about phenotype?
Well said Ms. Pacut.
Genotype is the set of genes in
our DNA which is responsible for
a particular trait.
Since we were finished with that, I
assume that you alreadt knew the
terms that I will be using later.
Phenotype is the physical
expression, or characteristics, of
that trait.
B. Lesson Proper
1. Motivation
Who among you here love animals?
Do you have pets in your house? What is
your pet Ms.
?What is its
color? Have you ever wondered
about their colors or why they got
that color?
(teacher will show a picture of cat)
(Some students raise their
hands)
Yes ma’am.
Dog mam.
Brown.
No mam.
Have
you
seen a
cat
that
looks
like
this?
Now who loves plants? (teacher will post a
picture of flower)
Especially flowers?
(Some will say yes and no)
So I
guess
girls
love
Yes Ma’am.
flowers right?
2.Discussion
Our lesson for today is about NonMendelian genetics. Do you have any idea
about this?
Non-Mendelian genetics, from the name
itself, it does not follow Gregor Mendel’s
Laws.
In Mendel’s Laws, If he were given a
mommy black mouse & a daddy white
mouse & asked what their offspring would
No Ma’am.
look like, he would've said that a certain
percent would be black & the others would
be white. He would never have even
considered that a white mouse & a black
mouse could produce other color of
mouse! For Mendel, the phenotype of the
offspring from parents with different
phenotypes always resembled the
phenotype of at least one of the parents.
Now, there are other patterns of inheritance
that do not follow these rules as I have said
earlier.
One of these is incomplete dominance.
With incomplete dominance, a cross
between organisms with two different
phenotypes produces offspring with a third
phenotype that is a blending of the parental
traits.
We can still use the Punnett Square to solve
problems involving incomplete
dominance. The only difference is that
instead of using a capital letter for the
dominant trait & a lowercase letter for the
recessive trait, the letters we use are both
going to be capital. Why do you think so?
Mr. Gapo?
Thank you. It’s because neither trait
dominates the other.
If you have a red flower cross with white
flower, what would be the color of the
offspring?
Why do say so?
(Teacher post a picture)
So the cross would look like this:
I think Pink Ma’am.
Because you said a while ago
that they are blending.
Because both of them are
dominant Ma’am.
So the cross would look like this:
(Teacher explains while writing on the
board)
A = allele for red flowers
B = allele for white flowers
Homozygous red flower crossed with a
homozygous white flower.
red (AA) x white (BB) ---> pink AB---> 100%
A
A
B
AB
AB
B
AB
AB
It's like mixing paints, red + white will make
pink. Red doesn't totally block (dominate)
the pink, instead there is
incomplete dominance, and we end up with
something in-between.
Another is co- dominance.
Given this example. (Teacher would show a
picture)
In co-dominance, the "recessive" &
"dominant" traits appear together in the
phenotype of hybrid organisms.
When we cross the alleles, (teacher draw a
Punnett square on the board)
Consider that these red cattle here is RR and
this white cattle is WW. If we cross these,
we yield all RW offsprings which means to
say that they are all red and white spotted.
Let’s proceed to sex-linked trait.
Sex-linked trait is also called as “X-linked”.
Why do you think? Do you have an idea Ms.
Agnes?
Because it occurs in X
chromosome Ma’am.
Very good! So which do you think is more
affected in this type of inheritance? Male or
I think Female Ma’am.
Female?
Ms. Bontilao?
Let’s find out!
As we all know, females have XX
chromosomes and males have XY
Yes Ma’am.
chromosomes. Right?
These chromosomes determine sex, so
genes located on these chromosomes are
known as sex-linked genes. The X
chromosome is much larger than the Y, so it
carries more genes than the Y chromosome.
Disorders that are sex-linked are much more
common in males, because they would only
need 1 recessive allele to have the trait;
rather than the two recessive alleles the
females need.
Take a look at this picture.
(teacher post a picture)
(teacher explain)
Another inheritance is Multiple Alleles. An
example of this is human blood type. In
humans, how many alleles for blood do we
have?
Another answer?
Who answered four? Three?
Ok, so There are three common alleles for
the gene that controls this characteristic.
The alleles IA, IB and i. IA and , IB are
dominant over i. Out of this three, only two
will exist in a diploid individual.
My question is, can an offspring will have a
type O blood if her parents are type A and
B?
Of course a child can be type O! Recall the
following:




Type A blood: IAIA, IAi
Type B blood: IB IB, IB i
Type AB blood: IAIB
Type O blood: ii
(teacher explain)
Another inheritance is polygenic
inheritance. From the word itself, polygene
which means that it is composed of many
genes not just one. Example of this is skin
color, eye color height, and etc.
Let us have the eye color as an
example. This trait is thought to be
influenced by up to 16 different genes.
Two of the genes that
influence eye color have been
identified on chromosome 15 (OCA2
and HERC2). Several other genes that
determine eye color also influence
skin color and hair color.
Understanding that eye color
is determined by a number of
different genes, for this example, we
will assume that it is determined by
two genes. In this case, a cross
Four Ma’am.
Three Ma’am.
(Some will say yes, some will say
no)





between two individuals with light
brown eyes (BbGg) would produce
several
different phenotype possibilities. In
this example, the allele for black
color (B) is dominant to the recessive
blue color (b) for gene 1. For gene 2,
the dark hue (G) is dominant and
produces a green color. The lighter
hue (g) is recessive and produces a
light color. This cross would result in
five basic phenotypes and
nine genotypes.
Black eyes: (BBGG)
Dark Brown eyes: (BBGg), (BbGG)
Light Brown eyes: (BbGg), (BBgg),
(bbGG)
Green eyes: (Bbgg), (bbGg)
Blue eyes: (bbgg)
Having all dominant alleles
results in black eye color. The
presence of at least two
dominant alleles produces the black
or brown color.
The presence of one
dominant allele produces the green
color, while having no dominant
alleles results in blue eye color.
The last one is the environmentallyinfluenced.


Genes play an important part in
determining our adult height. However,
factors such as poor nutrition can
prevent us from achieving our full
genetic potential.
Genes are a major determinant of
human skin color. However, exposure to
ultraviolet radiation can increase the
amount of pigment in the skin and make
it appear darker.
2. Practice Exercises
Go back to your group in performing the
drill. Choose a representative to pick your
task. Present your output in class. You have
five minutes to prepare and a maximum of
5 minutes to present your output in class.
1. Describe the relationship between
environment and phenotype.
2. Differentiate incomplete dominance
and
3. What are multiple alleles? Is there
dominance in multiple alleles?
co-dominance.
4. What is polygenic inheritance?
How does it work?
(students proceed to their
group)
After 5 minutes…
Ok . lets start with group 4.
5. Generalization
What is the common non-mendelian
inheritance that you observe in your
environment?
IV. Evaluation
V. Assignment
(start presenting)