Unit 3

Unit 3, Introduction to Biology

Pictured above is a replica of Anton van Leeuwenhoek's famous microscope (left), Robert Hooke's instant best-seller in 1665 (center), and Robert Hooke's microscope (right).

California Content Standards in this Unit:

Cell Biology

All living organisms are composed of cells, from just one to many trillions, whose details usually are visible only through a microscope. As a basis for understanding this concept:

Students know cells function similarly in all living organisms.
Students know the characteristics that distinguish plant cells from animal cells, including chloroplasts and cell walls.
Students know the nucleus is the repository for genetic information in plant and animal cells.
Students know that mitochondria liberate energy for the work that cells do and that chloroplasts capture sunlight energy for photosynthesis.

Investigation and Experimentation

Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will:

Select and use appropriate tools and technology (including calculators, computers, balances, spring scales, microscopes, and binoculars) to perform tests, collect data, and display data.
Construct scale models, maps, and appropriately labeled diagrams to communicate scientific knowledge (e.g., motion of Earth's plates and cell structure).

Robert Hooke's Drawing of Thinly Sliced Cork

Robert Hooke gets the credit for naming "cells" since they resemble a small monk's room called a cell.

About Unit 3:
In this unit, there are three major activities that help address several main ideas. The three activities are Microscope Labs, Study of a Living Organism, and Building a Cell Model. You should find activity sheets used in class below. Please be aware that activity sheets may vary depending on your teacher.

More on Microscopes:

Click HERE to watch that old video on Using Microscopes that we took notes on!

Basic microscope parts.

More on the Study of a Living Organism:

Mealworms in bran as a food source (left) and the adult stage beetle (right).

Additional links for Darkling Beetle/Mealworm:
Darkling Beetle/Mealworm - Center for Insect Science, University of Arizona
Darkling Beetle/Mealworm Rearing - Center for Insect Science, University of Arizona
Darkling Beetles - FOSSWeb
Mealworm - Wikipedia
Mealworm - EnchantedLearning
Here's the species we used in our study: Zophobas morio - Wikipedia

More on Building a Cell Model:
Scientists and students build models to better understand science concepts. They can also develop new ideas and hopefully make new discoveries after studying a model. This project requires each student to construct a realistic model of either a plant cell or an animal cell. Students are encouraged to use inexpensive materials to construct their model. Store purchased models will not be accepted for credit. Each model should contain all of the cell structures and organelles diagrammed in the class textbook. A legend listing each of the structures and organelles with their function and a small-scale version of each structure or organelle should also be included. There will be some class time allocated for students to work on their projects, but a student may find it necessary to work on their project outside of class in order to successfully complete the project by the assigned due date. Projects turned in after the assigned due date will have points deducted from the total.

HELPFUL HINTS FOR STARTING YOUR CELL MODEL AND SUCCESSFUL COMPLETION:
1. Choose either a general animal cell OR a general plant cell to build as your model.
2. Collect materials to build your cell model (must be 3D). Inexpensive materials like an old shoe box, yarn, pipe cleaners, etc., would be a great beginning. You can choose to show the organelles accurately or be more creative by intelligently selecting objects to represent the organelles.
3. Use your text book (page 22) as a guideline to which organelles you are required to include in your plant or animal cell. Please be aware that the cytoplasm (cytosol) is not shown in that diagram. The cytoplasm is the liquid (gelatin-like) area of the cell located between the nuclear membrane and the cell membrane. The cytoplasm is diagrammed and discussed on p.20 of your textbook. Review your cell model rubric for a list of each type of organelle which is required to be in your model.
4. Build your model. Your model should also have label pins (or another similar technique) for identifying each cell type of organelle or structure in your model.
5. Create a legend that tells the parts of your cell, descriptions, and functions. Your legend should also include an accurate colored drawing or smaller version of each organelle or cell structure in your model.
6. When you think you are finished, review the rubric your teacher has provided to make sure you have completed all of the requirements for your model.
7. Ask your teacher for assistance if you are confused or have any questions about how to construct your cell model.