Science Practices

Structure and Function

1. Develop an understanding of the basic structure and function of cells
2. Understand the relationship between cells, tissues, organs, and system
3. Analyze the different types of cells
4. Explain how cells maintain homeostasis
5. Understand the role of DNA in cell function and reproduction

• ATP – adenosine triphosphate, a molecule that provides energy for cellular processes.
  • Energy is released when an ATP molecule is converted to an ADP (adenosine diphosphate) molecule.
• Bacteria – unicellular organisms that contain cell walls and ribosomes but do not contain a nuclear membrane around their genetic material or other organelles common to plant and animal cells.
• Carbon dioxide – a colorless, odorless gas that is produced during respiration and combustion (burning).
  • Carbon dioxide is used by plants during photosynthesis.
  • The chemical formula of carbon dioxide is CO₂.
• Cell – the smallest structural and functional unit of all organisms that is said to be alive.
• Cellular respiration – a process by which energy is released from food.
  • When oxygen is present, oxygen and glucose combine to produce energy in the form of ATP molecules. The by-products of cellular respiration in the presence of oxygen are carbon dioxide and water.
  • When oxygen is not present, a smaller amount of energy is produced from the breakdown of glucose. Possible by-products include lactic acid and alcohol.
• Compound light microscope – an instrument used to magnify small objects. Two or more lenses (an eye piece and one of several objective lenses) collect light and bend it to create the larger image.

• Eukaryote – an organism in which the genetic material inside of cells is contained within a distinct nucleus.

• Multicellular – consisting of many cells.
  • Animals, plants, most fungi, and some protists are multicellular.

• Muscle cell – a long, contractile cell that forms the muscles of the body.
  • Muscle cells contract (shorten) and relax (lengthen) to produce movement.

• Neuron – a cell that is able to transmit nerve impulses (signals) from one part of the body to another.
• Organelle – a cell structure that performs a specific function.
  • Some examples of organelles are nuclei, cell membranes and chloroplasts.
    • A nucleus is an organelle that contains DNA and controls the cell by regulating when genes are turned on and off.
    • The cell membrane surrounds and protects the cell by regulating what can go in and out.
    • Chloroplasts are organelles that perform photosynthesis.

• Photosynthesis – the process by which light energy is used to combine water and carbon dioxide to produce glucose and oxygen.

• Prokaryote – single celled organisms that do not contain distinct nuclear membranes around their genetic material.
  • Bacteria are prokaryotes.

• Protist – eukaryotic organisms that are neither fungi, plants nor animals.
  • Most protists are unicellular.
  • Examples of protists are amoeba, Paramecium and Euglena.

• Red blood cell – a cell that uses hemoglobin to carry oxygen to the cells and tissues of the body. Red blood cells also carry carbon dioxide back to the respiratory organs.

• Root hair cell – a cell found in the roots of plants that absorbs water and nutrients from the soil.

• Tissue - a group of similar cells that work together to carry out a specific function.

• Together, several groups of tissues can form an organ.

• Unicellular – consisting of a single cell.
  • Unicellular organisms include bacteria, microalgae, and most protists.

• White blood cell – Cells in the blood that protect against invading pathogens.

• White blood cells are part of the immune system.

Sure, here are some of the main parts of a plant cell and their functions:

1. Cell Wall: This is the rigid outer layer that provides support and protection to the cell. It is made up of cellulose.

2. Cell Membrane: This is the outer layer of the cell that controls the movement of substances in and out of the cell.

3. Nucleus: This is the central part of the cell that contains the genetic material, such as DNA. The nucleus controls the activities of the cell and is responsible for cell division.

4. Chloroplasts: These are the organelles responsible for photosynthesis, the process by which plants make their own food. Chloroplasts contain chlorophyll, which gives plants their green color.

5. Mitochondria: These are the powerhouse of the cell. They convert food molecules into energy that the cell can use.

6. Endoplasmic Reticulum (ER): The ER is a network of membranes that is responsible for protein and lipid synthesis. There are two types of ER - the rough ER, which is studded with ribosomes, and the smooth ER, which does not have ribosomes.

7. Golgi Apparatus: This is a stack of flattened membranes that processes and packages proteins and lipids for transport to their final destination.

8. Ribosomes: These are small structures that are responsible for protein synthesis. They can be found free in the cytoplasm or attached to the rough ER.

9. Vacuole: This is a membrane-bound sac that stores water, ions, and other molecules. Plant cells have one large central vacuole that helps maintain cell turgor pressure and stores nutrients and waste products.

10. Cytoskeleton: This is a network of protein fibers that helps the cell maintain its shape and provides support.

These are some of the main parts of a plant cell and their functions.

Animal cells are eukaryotic cells, which means they have a true nucleus and membrane-bound organelles. Here are some of the main parts of an animal cell and their functions:

1. Cell Membrane: This is the outer layer of the cell that separates the interior of the cell from the external environment. The cell membrane controls the movement of substances in and out of the cell.

2. Nucleus: This is the central part of the cell that contains the genetic material, such as DNA. The nucleus controls the activities of the cell and is responsible for cell division.

3. Mitochondria: These are the powerhouse of the cell. They convert food molecules into energy that the cell can use.

4. Endoplasmic Reticulum (ER): The ER is a network of membranes that is responsible for protein and lipid synthesis. There are two types of ER - the rough ER, which is studded with ribosomes, and the smooth ER, which does not have ribosomes.

5. Golgi Apparatus: This is a stack of flattened membranes that processes and packages proteins and lipids for transport to their final destination.

6. Ribosomes: These are small structures that are responsible for protein synthesis. They can be found free in the cytoplasm or attached to the rough ER.

7. Lysosomes: These are small organelles that contain digestive enzymes. They break down waste materials and foreign invaders, such as bacteria.

8. Cytoskeleton: This is a network of protein fibers that helps the cell maintain its shape and provides support.

9. Centrosome: This is a structure that helps with cell division. It contains two centrioles.

10. Vacuole: This is a membrane-bound sac that stores water, ions, and other molecules. Plant cells have one large central vacuole, while animal cells have smaller, scattered vacuoles.

These are some of the main parts of an animal cell and their functions.

Lesson Plan: Exploring Cell Structure and Function

Objective

- Students will understand the basic structure and function of cells, including the key components of plant and animal cells.
- Students will appreciate how cells work together as a team to keep living organisms alive.

Materials:

- Visual aids (diagrams of plant and animal cells)
- Whiteboard and markers
- Student notebooks

**Duration:** Two 45-minute class periods

**Day 1: Introduction to Cell Structure**

**Introduction (10 minutes):**

- Begin by asking students what they know about cells. Write down their responses on the whiteboard.

**Activity 1: What Are Cells? (15 minutes):**

- Explain that cells are like the building blocks of living things.
- Show images of plant and animal cells and ask students to describe what they see.
- Discuss the basic idea that cells are tiny, but they have different parts with specific jobs, just like a factory.

**Activity 2: Cell Components (15 minutes):**

- Display a diagram of a plant cell and an animal cell.
- Ask students to identify and label the components of both types of cells (nucleus, chloroplasts - in plant cells, mitochondria, cell membrane, cell wall - in plant cells).
- Discuss the function of each component, using simple language.

**Activity 3: Interactive Activity (15 minutes):**

- Provide students with blank diagrams of plant and animal cells.
- In pairs or individually, have them label the components and describe their functions using their notes.
- Circulate to assist and answer questions.

**Day 2: How Cells Work Together**

**Review (10 minutes):**

- Begin with a quick review of the previous lesson, asking students to recall the components of plant and animal cells and their functions.

**Activity 4: Teamwork in Cells (20 minutes):**

- Explain that cells are like teams of workers. Each part has a specific job, but they need to work together.
- Use simple analogies, such as comparing the nucleus to a boss who gives orders and mitochondria to power generators.
- Discuss how teamwork in cells helps maintain life.

**Activity 5: Group Discussion (15 minutes):**

- Divide the class into small groups and give each group a scenario related to cellular teamwork (e.g., making energy, repairing damage).
- Have each group discuss how different cell components would work together to accomplish the task.

**Conclusion (10 minutes):**

- Summarize the key points of the lesson: cells have parts that do specific jobs, and these parts work together like a team.
- Reiterate the importance of understanding cells for understanding life.

**Assessment:**

- Assess student understanding through class participation, including discussions and activities.
- Optionally, assign a simple homework worksheet to reinforce concepts.

**Extensions:**

- For advanced students, provide additional information about cell types (prokaryotic and eukaryotic).
- Explore real-world applications of cellular teamwork, such as medical research or biotechnology.

MS-LS1-2 refers to one of the performance expectations from the Next Generation Science Standards (NGSS) for middle school life science. The objective of this performance expectation is:

MS-LS1-2: Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function.

This objective focuses on helping students understand the fundamental unit of life, which is the cell. Students will learn that cells are the building blocks of all living organisms and that they have specific structures that enable them to carry out their functions.

To achieve this objective, students will need to develop an understanding of the different parts of a cell, such as the nucleus, cell membrane, mitochondria, and ribosomes. They will need to understand the functions of these parts and how they work together to enable the cell to carry out its functions.

In addition to developing an understanding of cell structures and functions, students will need to develop skills in modeling. They will need to create and use models to describe the function of a cell and how its parts contribute to that function. This may involve creating physical models or digital models, as well as using diagrams and other visual representations to communicate their understanding.

By the end of this performance expectation, students should be able to explain the basic functions of a cell, identify the different parts of a cell and their functions, and develop and use models to describe the function of a cell as a whole.

Title: Comparing Animal and Plant Cells

Grade Level: Middle School (6th - 8th grade) NGSS Standard: MS-LS1-2 - Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function.

Objective:

1. Students will compare and contrast the structures and functions of animal and plant cells.
2. Students will develop a model of an animal and plant cell to demonstrate their understanding of cell structure and function.

Materials:

• Textbooks or online resources with information on animal and plant cells
• Poster boards or large paper
• Art supplies (markers, colored pencils, etc.)
• Cell organelle cards or images (optional)
• Microscopes (optional)

Procedure:

1. Introduction (10 minutes):

   • Begin by asking students about the basic unit of life and discuss the importance of cells in living organisms.
   • Explain that cells can be classified into different types, such as animal and plant cells, which have distinct structures and functions.
   • Share the objectives of the lesson with the students.

2. Background Knowledge (15 minutes):

   • Provide students with textbooks or online resources to gather information about animal and plant cells.
   • Guide students to focus on the structures and functions of each cell type, including cell membrane, cytoplasm, nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, vacuoles, chloroplasts (for plant cells), and cell wall (for plant cells).
   • Encourage students to take notes or create a table comparing the structures and functions of animal and plant cells.

3. Comparing Animal and Plant Cells (20 minutes):

   • Divide students into pairs or small groups.
   • Provide each group with a poster board or large paper and art supplies.
   • Instruct students to create a visual representation of an animal cell on one side of the poster board and a plant cell on the other side.
   • Students should label the different cell structures and include brief descriptions of their functions.
   • Encourage creativity and accuracy in their illustrations.

4. Presentations and Discussions (15 minutes):

   • Ask each group to present their posters to the class, explaining the structures and functions of animal and plant cells.
   • Facilitate a class discussion by comparing the similarities and differences between the two types of cells.
   • Encourage students to ask questions and provide additional insights.

5. Optional Extensions:

   • If microscopes are available, students can observe prepared slides of animal and plant cells to visualize the structures discussed.
   • Students can create 3D models of animal and plant cells using modeling clay or other materials.
   • Students can research and present on specialized cells found in different organisms, such as red blood cells, nerve cells, or root hair cells.

6. Conclusion (5 minutes):

   • Recap the main points of the lesson, emphasizing the similarities and differences between animal and plant cells.
   • Emphasize the importance of cells as the building blocks of life and their role in maintaining the functions of living organisms.

Assessment:

• Assess students' understanding through their participation in class discussions, group presentations, and accuracy of their visual representations of animal and plant cells.
• Evaluate students' ability to compare and contrast the structures and functions of animal and plant cells in their notes, tables, or posters.

Note: Adapt the lesson plan duration and activities based on the available class time and resources.

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4. Killer T Cell - The Cancer Assassin
5. Darius Goes West

Assess student understanding of the lesson by asking them to explain the function of a cell and the roles of its different parts. Assess their ability to create and use models to describe the function of a cell as a whole and ways parts of cells contribute to the function.