Viruses and bacteria

Grade 11 · Biology

Semester 1 | Period 1 | Week 1

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Subject: Biology

Semester: 1

Period: 1

Week: 1

School Name:
Teacher’s Name:
Subject: Biology
Grade Level: Grade 11
Date: Week 1
Lesson Duration: 45 minutes
Week & Term: Week 1, Period I
Topic: Viruses and Bacteria
Sub-topic:
• Introduction to Viruses
• General Characteristics and Structure of Viruses
• Classification of Viruses – DNA and RNA viruses

 

Learning Objectives

By the end of the lesson, students should be able to:

  1. Define a virus
  2. List the general characteristics of viruses
  3. Identify and label parts of a virus
  4. Classify viruses based on their genetic material – DNA or RNA

 

Previous Knowledge

Students already know:
• Living and non-living things
• Characteristics of microorganisms

 

Instructional Materials

  • Chart showing viral structures
    • Video clip or animation of virus attacking a cell
    • Models or drawings of bacteriophage, HIV, Influenza virus
    • Flashcards with DNA/RNA virus names
    • Students' notebooks and pencils

 

Lesson Development – ABC Model

A – Anticipation (Warm-up / Starter)

Time: 5–10 mins
Activity:
Ask: “Have you ever had the flu or chickenpox? What do you think caused it?”
Let learners brainstorm and share prior knowledge about common illnesses and what they think viruses are.

Teacher’s Role: Prompt students to connect real-life experiences to viruses.
Learner’s Role: Share observations and respond to open-ended questions.

 

B – Building Knowledge (Main Lesson Body)

Time: 25–30 mins
Teacher explains:
• Definition of Virus: A virus is a tiny infectious agent that can only reproduce inside the living cells of a host organism.
• Characteristics:
– Not considered truly living: they cannot reproduce, feed or grow on their own.
– Lack cell structure but have genetic material (either DNA or RNA).
– Extremely small; visible only under electron microscope.
• Structure:
– Consist of a protein coat (capsid) and genetic material (DNA or RNA).
– Some viruses have an envelope made of lipids.
• Classification:
– DNA Viruses: Examples include Herpes virus, Smallpox virus
– RNA Viruses: Examples include Influenza virus, HIV

Learners’ Activities (Expanded):
• Watch a short video or diagram animation showing a virus invading a cell
• In pairs, draw and label a virus structure (capsid, genetic material, envelope if present)
• Group classification activity: Sort virus names into DNA or RNA categories using flashcards
• Complete a short matching game: virus name ↔ genetic material type

Assessment Checks:
✓ Oral questioning after video viewing
✓ Label virus parts correctly on diagram
✓ Group feedback and quiz on classification

 

Notes (Expanded):

Viruses are not fully alive because they cannot grow or reproduce on their own. They are much smaller than bacteria and require a host to multiply. Every virus has a core of DNA or RNA surrounded by a protective protein shell called a capsid. Some viruses also have an outer envelope.
Viruses are classified based on their nucleic acid:

  • DNA viruses store genetic material as deoxyribonucleic acid.
  • RNA viruses use ribonucleic acid as their genetic material.
    Examples of viral diseases include chickenpox (caused by a DNA virus) and HIV (caused by an RNA virus).

 

C – Consolidation (Conclusion & Assessment)

Time: 5–10 mins
Summary:
Teacher recaps key points: definition of virus, characteristics, structural parts, and classification by DNA/RNA.

Evaluation Method (Expanded):
• Individual worksheet with a fill-in-the-blank diagram of a virus
• Written short answer quiz: “What makes viruses different from living organisms?”
• Oral review quiz: DNA or RNA? Students raise cards to show correct classification

 

Assignment (Expanded):

  1. In your notebook, list 3 examples of DNA viruses and 3 RNA viruses.
  2. Draw a labelled diagram of any virus (e.g., HIV or bacteriophage).
  3. Interview an adult about a time they had a viral disease—write 3–5 sentences about what they shared.
  4. Research: What is the difference between a virus and a bacterium? Come prepared to share next week.

 

Differentiation / Inclusive Strategies

  • Struggling Learners: Use labeled visuals and teacher-guided drawing
    • Advanced Learners: Research a new or emerging virus (e.g., coronavirus variants)
    • Students with Disabilities: Provide pre-labeled diagrams with large print and audio description

 

Teacher’s Reflection (After Class)

• What worked well?
• What needs improvement?
• Students’ engagement level: □ High □ Medium □ Low
• Next steps: Introduce common viral diseases and the viral life cycle next week.