Exploring Movement in Cells: Cyclosis, Organ Cells, and Growth Regulation Biology SS 1 First Term Lesson Notes Week 9
Subject: Biology
Class: SS1
Term: First Term
Week: 9
Age (years): 15-16
Topic: Movement
Sub-topic: Types and Mechanisms of Movement in Cells
Duration: 2 hours
Behavioural Objectives:
By the end of this lesson, students should be able to:
- Define movement and explain its significance in cells.
- Describe the process of cyclosis and its role in intracellular transport.
- Identify the organ cells responsible for movement in various organisms.
- Explain how auxins regulate growth movements in plants.
Keywords:
Movement, Cyclosis, Organ Cells, Auxins, Growth Movement
Set Induction:
Begin the lesson by asking students to observe and discuss how plants grow towards light and how some cells move. Use examples from everyday life, such as plant growth and animal locomotion, to illustrate the concept of movement.
Entry Behaviour:
Students should have prior knowledge of cell structure and basic cellular functions from previous lessons.
Learning Resources and Materials:
- Diagrams illustrating cyclosis and plant growth movement
- Videos showing movement in cells and plants
- Charts explaining the role of auxins in growth
- Interactive simulations demonstrating cell movement
Building Background / Connection to Prior Knowledge:
Connect this lesson to previous discussions about cell functions, emphasizing how movement is crucial for processes like nutrient transport and growth in organisms.
Embedded Core Skills:
- Analytical skills: Understanding how and why cells move.
- Collaborative learning: Working in groups to discuss examples of movement in different organisms.
- Research skills: Investigating the role of auxins in plant growth.
Learning Materials:
- Textbook: “Biology for Senior Secondary Schools”
- Online resources for interactive learning about cyclosis and plant movements
- Worksheets summarizing key concepts
Reference Books:
- Biology for Senior Secondary Schools by E. B. Olaniyan
- Comprehensive Biology by J. A. Akintunde
Instructional Materials:
- PowerPoint presentations with graphics illustrating cyclosis and growth movement
- Models demonstrating different types of organ cells involved in movement
- Handouts outlining the role of auxins in regulating growth
Content:
1. Movement: Movement in biological terms refers to the ability of organisms and their cells to change position or location. It can be observed in various forms, such as growth towards stimuli, locomotion, and the movement of cellular components.
2. Cyclosis:
- Definition: Cyclosis is the streaming movement of cytoplasm within a cell, allowing for the distribution of nutrients and organelles. This process ensures that vital substances are transported to various parts of the cell efficiently.
- Process: In plant cells, cyclosis can be observed as a circular movement of the cytoplasm around the vacuole. This movement helps distribute chloroplasts for maximum light absorption during photosynthesis.
- Example: In Elodea (waterweed), cyclosis can be observed under a microscope as chloroplasts move along the cell membrane, enhancing the efficiency of photosynthesis.
3. Organ Cells for Movement:
- Certain specialized cells in multicellular organisms are responsible for movement. These include:
- Muscle Cells: In animals, muscle cells (myocytes) contract and relax to enable movement, such as running or swimming.
- Cilia and Flagella: These are hair-like structures that help certain cells, like sperm cells and some protozoa, to swim.
- Pseudopodia: In organisms like amoeba, extensions of the cell body allow it to move and engulf food.
4. Growth Movement Regulated by Auxins:
- Auxins: Auxins are plant hormones that play a crucial role in regulating growth. They influence the direction of growth in response to environmental stimuli (phototropism and gravitropism).
- Growth Movements: When auxins are concentrated on one side of a plant, they promote elongation of cells on that side, causing the plant to bend toward the light (positive phototropism) or away from gravity (negative gravitropism).
- Example: In a growing plant stem, if light is directed from one side, auxins will accumulate on the shaded side, causing those cells to elongate more than those on the light side, resulting in the plant bending towards the light source.
Evaluation:
Fill-in-the-Blank Questions (15 Questions):
- The streaming movement of cytoplasm within a cell is known as _____. a) Phagocytosis
b) Cyclosis
c) Diffusion
d) Osmosis - Organ cells responsible for movement in animals are called _____. a) Muscle Cells
b) Epithelial Cells
c) Nerve Cells
d) Connective Cells - Auxins are plant hormones that regulate _____. a) Metabolism
b) Photosynthesis
c) Growth Movements
d) Respiration - Cyclosis helps in the distribution of _____ within the cell. a) Proteins
b) Waste
c) Nutrients
d) All of the above - Muscle cells contract and relax to enable _____. a) Growth
b) Circulation
c) Movement
d) Digestion - The movement of cilia and flagella aids in the _____ of certain cells. a) Growth
b) Protection
c) Locomotion
d) Reproduction - In phototropism, plants grow toward _____. a) Water
b) Light
c) Gravity
d) Nutrients - Auxins promote cell _____ on the side of the plant that is away from light. a) Division
b) Expansion
c) Differentiation
d) Specialization - The ability of an organism to move from one place to another is called _____. a) Mobility
b) Irritability
c) Stability
d) Inertia - Cyclosis can be observed in _____ cells. a) Animal
b) Plant
c) Both a and b
d) None of the above - The _____ of auxins causes the bending of plants toward the light. a) Distribution
b) Absence
c) Production
d) Decomposition - Pseudopodia are extensions found in _____ cells. a) Epithelial
b) Muscle
c) Amoeba
d) Nerve - Cyclosis is important for _____ within the cell. a) Movement
b) Communication
c) Nutrient Transport
d) Both a and c - Auxins are synthesized primarily in _____. a) Roots
b) Leaves
c) Stems
d) Flowers - Organisms that use cilia for movement include _____. a) Amoeba
b) Paramecium
c) Euglena
d) All of the above
Class Activity Discussion: FAQs (15 Questions and Answers):
- Q: What is cyclosis? A: Cyclosis is the streaming movement of cytoplasm within a cell, which helps in the distribution of nutrients and organelles.
- Q: How do auxins affect plant growth? A: Auxins regulate cell elongation, allowing plants to grow toward light and roots to grow downward.
- Q: What types of cells are involved in movement? A: Muscle cells, ciliated cells, and cells with pseudopodia are all involved in movement in different organisms.
- Q: Can you explain phototropism? A: Phototropism is the growth of plants toward light due to the unequal distribution of auxins.
- Q: What role do muscle cells play in movement? A: Muscle cells contract and relax, enabling animals to move.
- Q: What are cilia and flagella? A: Cilia and flagella are hair-like structures that help some cells move through fluids.
- Q: How does cyclosis benefit plant cells? A: Cyclosis facilitates the distribution of chloroplasts and nutrients, enhancing photosynthesis and overall cell function.
- Q: What happens if auxin levels are too high? A: Excess auxin can lead to abnormal growth, including excessive elongation or deformation of plant structures.
- Q: How do auxins influence root growth? A: Auxins promote cell elongation on the side of the root that is away from gravity, allowing roots to grow downward.
- Q: Can cells move without muscle cells? A: Yes, many unicellular organisms and some plant cells can move through other mechanisms, such as cyclosis or the use of cilia.
- Q: What is gravitropism? A: Gravitropism is the growth response of plants to gravity, with roots growing downward and stems growing upward.
- Q: How do auxins interact with other plant hormones? A: Auxins work with other hormones like gibberellins and cytokinins to regulate growth and development.
- Q: What are some examples of organisms that use pseudopodia for movement? A: Amoeba is a classic example of an organism that uses pseudopodia for movement and feeding.
- Q: Why is movement important for cells? A: Movement is essential for processes like nutrient transport, waste removal, and overall cellular function.
- Q: How does cyclosis differ from other types of movement? A: Cyclosis is a specific intracellular process, while other movements refer to the movement of whole organisms or organs.
Presentation:
Step 1: Review the previous topic on cellular respiration and energy release, connecting it to how movement requires energy.
Step 2: Introduce the new topic on movement, explaining cyclosis, organ cells, and the role of auxins using diagrams and videos.
Step 3: Encourage student contributions by discussing how different organisms move and how that relates to their environments.
Activities:
Teacher’s Activities:
- Demonstrate cyclosis using live cell samples under a microscope.
- Use animations to illustrate the effect of auxins on plant growth.
- Facilitate discussions on the importance of movement in both unicellular and multicellular organisms.
Learner’s Activities:
- Observe and document cyclosis in plant cells during microscope sessions.
- Engage in group activities discussing real-life examples of movement.
- Complete fill-in-the-blank questions and participate in evaluation exercises.
Assessment:
Evaluation Questions (10 Questions):
- What is cyclosis?
- Name three types of cells involved in movement.
- How do auxins affect plant growth?
- Explain the significance of muscle cells in animals.
- Describe how plants respond to light and gravity.
- What are cilia and their function?
- How does movement benefit unicellular organisms?
- Discuss the effects of excess auxin on plant growth.
- What is the difference between phototropism and gravitropism?
- How do pseudopodia assist amoeba in movement?
Conclusion:
The teacher will review students’ responses and assess their understanding of movement mechanisms in cells. Students will be encouraged to reflect on how these processes are essential for life, adaptation, and survival in different environments.