The Good Shepherd School of Imelda, Inc.
RIVERSIDE, IMELDA, ZAMBOANGA SIBUGAYSEC. REG. #G19700393
GOVERNMENT PERMIT No. 37 S. 2015 (PRESCHOOL TO COMPLETE ELEMENTARY)
GOVERNMENT RECOGNITION (R-IX) NO. 002, S. 2008 (COMPLETE SECONDARY COURSE)
LESSON PLAN
Name of Teacher Christy P. Betita Subject SCIENCE
Grade Level 9 Time Allotment 1 Hour
Time Schedule August/Daily Time Frame 1:00pm-2:00pm
Quarter 1st/ Week 4 Evaluation Items 10 items
TOPIC Non-Mendelian Patterns of Inheritance
UNIT STANDARD CONTENT STANDARD
The learners demonstrate understanding how genetic information is organized in
genes on chromosomes 2. the different patterns of inheritance
PERFORMANCE STANDARD
The learners should be Explain the different Non-Mendelian Patterns of Inheritance
PRIOR Reviewing previous lesson.
KNOWLEDGE
A. Reviewing previous
lesson or presenting
the new lesson
ESSENTIAL What distinguishes Mendelian from Non-Mendelian inheritance patterns?
QUESTIONS How do incomplete dominance and codominance differ, and what are examples of
B. Establishing a each?
purpose of the lesson How are sex-linked traits inherited differently in males and females?
What is the significance of multiple alleles in human blood types?
What are sex-limited and sex-influenced traits, and how do they differ in expression
between sexes?
ESSENTIAL Mendelian inheritance follows Gregor Mendel's laws, where traits are determined by
UNDERSTANDING single genes with two alleles that segregate and assort independently, often resulting
in dominant and recessive patterns. In contrast, Non-Mendelian inheritance includes
patterns that do not follow Mendel's laws, such as incomplete dominance,
codominance, multiple alleles, polygenic traits, and sex-linked traits. Incomplete
dominance occurs when a heterozygous phenotype is intermediate between the two
homozygous phenotypes, like pink flowers from red and white snapdragons, while
codominance involves both alleles being fully expressed, such as in speckled
chickens or the AB blood type in humans. Sex-linked traits are associated with
genes on the sex chromosomes and are inherited differently in males and females;
for example, X-linked traits like hemophilia are more common in males, who have
only one X chromosome. Multiple alleles, such as those in the ABO blood group
system, result in more diverse phenotypes, as three alleles (IA, IB, and i) can
combine to produce four blood types. Sex-limited traits are expressed in only one
sex, like lactation in female mammals, while sex-influenced traits, such as pattern
baldness, are expressed in both sexes but more frequently in one due to hormonal
differences.
OBJECTIVES Within the given period the Grade 9 students are expected to do the following with
at least 75% level of accuracy:
1. explain the incomplete dominance pattern of inheritance
2. describe codominant traits
3. determine all possible combinations of genes for a specific blood type
4. determine the probability of having a male and female gender
5. explain the sex-linked and sex influenced trait
VALUES
INTEGRATION
RESOURCES Government of the Philippines, Department of Education. 2015. Grade 9 Learner’s
Material. Manila.
LESSON PROPER
STAGES ACTIVITIES
Exploration Time Allotment: Day: Tuesday
(EXPLORE) Where Do I Belong?
Presenting The following pictures show the cross between organisms based on their phenotypes. Match
examples/insta each given pair of organisms in Column A with its possible offspring in Column B, then
nces of the new write your answer for the following questions on a separate sheet of paper.
lesson
Explanation Time Allotment: 1 hour Day: Tuesday
(FIRM UP) A Mendelian pattern of inheritance refers to reproducing organisms
D. Discussing new sexually. We know that in Mendel’s principles of heredity each parent gives one
concepts and of two possible alleles for a trait. However, Non-Mendelian inheritance is any
practicing new pattern of inheritance wherein traits do not segregate following Mendel’s law.
skills These laws describe the inheritance of traits linked to single genes on
chromosomes in the nucleus.
Incomplete dominance. Snapdragon flower is an example of this pattern of
inheritance in which both alleles are present resulting in an intermediate
phenotype.
A cross between a homozygous red-flowered plant (F RFR) and a homozygous
white-flower plant (FWFW) will produce offspring with pink flowers (F RFW) as shown
in the F1 generation.
A cross between two heterozygotes of F1 generation, however, will result in
an F2 generation with a phenotype of 25% red flowers, 50% pink flowers, and
25% white flowers (phenotypic ratio of 1:2(blended traits):1).
Codominance is a heterozygote condition wherein both traits are present
simultaneously, rather than one fully determining the phenotype. A speckled
chicken is a good example of dominance.
A cross between a black and white chicken will produce chicken with both
black and white feathers. The alleles for black feathers in some varieties
of chicken is codominant with the allele for white feathers.
Another example that shows how the co-dominance pattern of inheritance is determined by
genes is in the blood typing in humans. An antigen is a protein- bound to a sugar molecule found on
the surface of our red blood cells. A pair of alleles (IA and IB) which controls one group of antigens,
help in determining the blood types of an individual.
Table 1. Summary of phenotypes and genotypes of the blood typing in humans.
In the heterozygote condition, both IA and IB alleles are expressed in the red blood cells that will have
the antigens A and B. Three alleles exist in the ABO system: A, B, and O. This result in four blood
types: A, B, O, and the blended AB.
Codominance in Human Blood Types Figure from Creative Commons
Multiple Alleles: (ABO Blood Types)
A single gene that has more than two alleles is called multiple alleles. The ABO
blood groups in humans as an example of a gene that has multiple alleles is the
one that controls the inheritance. There are four blood group systems A, B, AB,
and O.
Sex-Linked Genes
Sex-linked genes are genes found either on X or Y chromosomes which are
inherited differences among male and a female. Sex-linked traits determined by
an X-linked gene when an X chromosome takes control. On the other hand, the
so- called Y-linked genes are those located on the Y chromosome.
A woman suffering from Hemophilia
Figure from Creative Commons
⮚ Hemophilia, an example of an X-linked trait is a rare genetic disorder in
which a person lacks enough blood-clotting proteins caused by a change in one
of the genes.
Since this phenomenon is sited on the X chromosome, females identified to
have affected two X chromosomes cause the disorder. But if there is only one
chromosome affected, the female individual is referred to as “carrier” of the
disorder.
Color-blindness is another condition of the X-linked trait. These traits will be
manifested in females who have two genes of color-blindness. Meanwhile, in
males, there is only one gene of the disorder needed to express the
phenomenon.
Table 3. Genotypes and phenotypes in humans
Genotype Phenotype
XX Normal female
X XC Normal female,
carrier of the gene
XC XC Color-blind female
XY Normal male
C
X Y Color-blind male
Hypertrichosis pinnae auris is a Y-linked trait controlled by a Y chromosome
and characterized by hairy ear in which are expressed in males alone. This
human condition can be inherited from a father who has the disorder, to his
sons who, in turn, will pass it on to their sons.
will pass it on to their sons.
Sex-Limited Trait
Sex-limited traits are those traits limited to only one sex. Lactation is a good
example of a sex-limited trait that is exclusively exhibited among females.
However, cattle carry genes for lactation on both males and females.
Lactating gene (L) is a dominant gene over the non-lactating recessive gene (l).
In female cattle carrying one dominant gene (XXLl), or two dominant genes
(XXLL) lactation will be shown. Nevertheless, neither male cattle having
dominant genes nor in male cattle that have recessive genes will lactate.
Sex-Influenced Traits
Sex-influenced traits are autosomal traits that are expressed in both sexes but
more frequently in one than in the other sex. One classic example of this is
pattern baldness which is expressed in females but is more often manifested
in males.
The gene has two alleles, “bald” (B) and “non-bald” (b), and these genes are
highly influenced by the hormones individually. We know that all humans have
testosterone, but males have higher level of testosterone than females do. This
shows that, although baldness alleles (XY BB, XYBb, or XXBB) behave like a
dominant allele in males, they are recessive in females (XX Bb, XXb).
Exposition Time Allotment: Day: Thursday
(DEEPEN) Non-Mendelian inheritance patterns extend beyond Mendel's classic principles,
E. Making demonstrating more complex genetic interactions. Unlike Mendelian inheritance, where traits
generalizatio follow predictable ratios based on dominant and recessive alleles, Non-Mendelian patterns
ns and
involve phenomena such as incomplete dominance, codominance, multiple alleles, and sex-
abstractions
about the linked traits. Incomplete dominance results in a blended phenotype, as seen in snapdragon
lesson flowers, while codominance presents both alleles simultaneously, exemplified by speckled
chickens and human blood types. Multiple alleles, such as those governing ABO blood
groups, contribute to a range of phenotypes. Sex-linked traits, such as hemophilia and color
blindness, show distinct inheritance patterns based on X and Y chromosomes, affecting
males and females differently. Sex-limited traits, like lactation in cattle, are expressed in only
one sex, while sex-influenced traits, such as pattern baldness, vary in expression between
sexes due to hormonal influences. These patterns highlight the complexity and variability in
genetic inheritance beyond Mendelian expectations.
Integration Time Allotment:
(TRANSFER) RASP Activity: Exploring Non-Mendelian Patterns of Inheritance
F. Creating a Goal:
Realistic To understand and explain Non-Mendelian inheritance patterns (incomplete dominance,
Performanc codominance, multiple alleles, sex-linked traits, sex-limited traits, and sex-influenced traits)
e Output and illustrate their implications through real-world examples.
Role:
You are a genetic counselor or a high school biology teacher.
Audience:
Your audience consists of high school students who are learning about genetics for the first
time, or a group of clients/patients who are interested in understanding their genetic
conditions.
Situation:
You have been tasked with preparing an informative and engaging presentation (as a teacher)
or a detailed report (as a genetic counselor) that clearly explains Non-Mendelian patterns of
inheritance. Your goal is to educate your audience about these patterns, how they differ from
Mendelian inheritance, and their significance in real-world genetics.
Product/Performance:
1. Presentation (for teachers): Create a 10-15 slide presentation using tools like
PowerPoint or Google Slides that includes:
o An overview of Non-Mendelian inheritance.
o Detailed explanations of incomplete dominance, codominance, multiple
alleles, sex-linked traits, sex-limited traits, and sex-influenced traits.
o Real-world examples and visuals (e.g., Punnett squares, diagrams of
inheritance patterns, photos of organisms displaying these traits).
o An interactive component, such as a quiz or group discussion question, to
engage the audience.
Evaluation Time Allotment: 1 hour Day: Tuesday
(TRANSFER) 1. What is the primary difference between Mendelian and Non-Mendelian
inheritance patterns?
o a) Mendelian inheritance involves multiple genes, while Non-Mendelian
involves a single gene
o b) Mendelian inheritance follows predictable ratios based on alleles,
while Non-Mendelian inheritance does not follow these predictable
patterns
o c) Non-Mendelian inheritance follows Mendel's laws, while Mendelian does
not
o d) Mendelian inheritance only occurs in plants
Answer: b) Mendelian inheritance follows predictable ratios based on alleles, while Non-
Mendelian inheritance does not follow these predictable patterns.
2. Which of the following is an example of incomplete dominance?
o a) Blood type AB in humans
o b) A speckled chicken with black and white feathers
o c) Pink flowers from a cross between red and white snapdragons
o d) Color-blindness in humans
Answer: c) Pink flowers from a cross between red and white snapdragons.
3. What is the phenotypic ratio in the F2 generation when two heterozygous
snapdragon plants (pink flowers) are crossed?
o a) 3:1
o b) 1:2:1
o c) 1:3
o d) 2:2
Answer: b) 1:2:1.
4. In codominance, which of the following is true?
o a) Only one allele is fully expressed
o b) Neither allele is expressed
o c) Both alleles are fully expressed simultaneously
o d) A blended intermediate phenotype is produced
Answer: c) Both alleles are fully expressed simultaneously.
5. Which human trait is an example of codominance?
o a) Blood type O
o b) Blood type AB
o c) Red-green color blindness
o d) Lactation in females
6. What are sex-linked genes?
o a) Genes located on autosomes
o b) Genes found on the X or Y chromosomes
o c) Genes that are only found in males
o d) Genes that determine blood type
7. Which of the following is an example of an X-linked trait?
o a) Pattern baldness
o b) Hemophilia
o c) Blood type O
o d) Lactation
Answer: b) Hemophilia.
8. What is the inheritance pattern for hypertrichosis pinnae auris (hairy ears)?
o a) X-linked dominant
o b) Y-linked
o c) Autosomal recessive
o d) Autosomal dominant.
9. What defines a sex-limited trait?
o a) A trait that is only found in males
o b) A trait that is expressed in only one sex but can be carried by both
sexes
o c) A trait that is equally expressed in both sexes
o d) A trait that is influenced by hormones
Answer: b) A trait that is expressed in only one sex but can be carried by both sexes.
10. Which of the following describes a sex-influenced trait?
a) A trait expressed equally in both sexes
b) A trait expressed only in females
c) A trait influenced by sex hormones and expressed differently in males and
females
d) A trait carried on the Y chromosome
Answer: c) A trait influenced by sex hormones and expressed differently in males and
females.
Criteria for 21-24 points: Excellent understanding, presentation, and creativity; exceeds expectations in
Evaluation all areas.
16-20 points: Good understanding and presentation with creative elements; meets most
expectations.
11-15 points: Satisfactory understanding and presentation; some creativity present but needs
improvement in several areas.
6-10 points: Needs significant improvement in understanding, presentation, and creativity.
Performance Time Allotment: Day: Monday
Output The students will present their output in front.
(TRANSFER)
Advance Study how changes in the environment may affect species extinction
