Genetics, Sexuality, and Evolution

Grade 11 · Biology

Semester 2 | Period 5 | Week 26

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Subject: Biology

Semester: 2

Period: 5

Week: 26


School Name:
Teacher’s Name:
Subject: Biology
Grade Level: Grade 11
Date: Week 26
Lesson Duration: 45 minutes
Week & Term: Week 26, Period V
Topic: Genetics, Sexuality, and Evolution
Sub-topic: Mendel’s Work, Genetic Terms, Hereditary Traits, Blood Grouping

 

Learning Objectives

By the end of this lesson, learners should be able to:

  1. Define genetics, heredity, and related terms like phenotype, genotype, alleles, homozygous, heterozygous, hybrid.
  2. Explain Mendel’s experiment with garden peas and how it led to modern genetics.
  3. Predict outcomes using Mendel’s laws of inheritance.
  4. Identify examples of hereditary traits in humans.
  5. Describe ABO blood grouping and Rh factor.

 

Previous Knowledge

Students have studied DNA structure and protein synthesis. They understand traits are controlled by genes.

 

Instructional Materials

  • Picture charts of pea plant traits
  • Punnett square boards
  • Flashcards of genetic terms
  • Charts showing human hereditary traits
  • Diagram of blood groups and Rh factor

 

Lesson Development – ABC Model

A – Anticipation (Warm-up / Starter)

Time: 5–10 mins
Ask students: “Do you look more like your mother or your father? Why do you think that is?”
Lead into how traits are passed from parents to offspring.

 

B – Building Knowledge (Main Lesson Body)

Time: 25–30 mins

Notes (Expanded and Detailed):

  • Genetics is the study of how traits are passed from parents to offspring.
  • Heredity is the transmission of traits.
  • Gregor Mendel was a monk who studied pea plants and discovered how traits are inherited in predictable patterns.
  • Key terms:
    • Gene: A section of DNA that controls a trait.
    • Alleles: Different forms of a gene (e.g., tall or short).
    • Phenotype: The visible trait (e.g., tall).
    • Genotype: The genetic makeup (e.g., TT, Tt, tt).
    • Homozygous: Two identical alleles (TT or tt).
    • Heterozygous: Two different alleles (Tt).
    • Hybrid: Another name for heterozygous.
  • Mendel’s Law of Segregation: Each parent passes only one allele to offspring.
  • Law of Independent Assortment: Genes for different traits sort independently.
  • Human Traits: e.g., earlobe shape, tongue rolling, dimples, blood types.
  • ABO Blood Groups:
    • A, B, AB, and O.
    • Controlled by alleles: A and B are dominant; O is recessive.
  • Rh Factor: Rh+ (dominant), Rh− (recessive). Important in blood transfusions.

 

Learners’ Activities (Expanded)

  • Use Punnett squares to predict the outcome of genetic crosses (e.g., TT x tt, Tt x Tt).
  • Role-play alleles and form "offspring" genotypes.
  • Match flashcards of genetic terms to definitions.
  • Identify dominant and recessive traits in classmates through surveys.
  • Class discussion: What blood groups can safely donate to whom?

 

Assessment Checks

  • Quick quiz: Define genotype and phenotype with examples.
  • Punnett square problem: “If a Tt plant mates with a Tt, what percentage will be tall?”
  • Peer-to-peer questioning using trait cards.

C – Consolidation (Conclusion & Assessment)

Time: 5–10 mins
Recap how Mendel’s laws explain how traits are passed on, and why some may appear or skip generations.

 

Assignment (Expanded)

  1. Draw a Punnett square for a cross between a homozygous tall plant and a homozygous short plant.
  2. Write a paragraph explaining Mendel’s first law.
  3. Research and list five inherited traits in your family.
  4. Make a diagram showing the ABO and Rh blood groups with compatible donors.

 

Differentiation / Inclusive Strategies

  • Struggling learners: Use color-coded alleles and simplified charts.
  • Advanced learners: Predict dihybrid crosses (e.g., TtRr x TtRr).
  • Students with disabilities: Offer audio explanations and tactile Punnett square kits.

 

Teacher’s Reflection (After Class)

  • Were learners able to grasp basic genetic concepts?
  • Did the Punnett square activity reinforce learning?
  • What areas need revision or extra support?