Lesson 3.1 Teacher’s Guide

Cells: Introduction to Cells

Standards:

• 9.4.1.2 Cells and cell structures have specific functions that allow an organism to grow, survive and reproduce.

Benchmarks:

• 9.4.1.2.3 Describe how viruses, eukaryotic, and prokaryotic cells differ in relative size, complexity, and general structure.

Tentative Timeline:

Lesson 3.1 Introduction to cells suggested answer key

3.1.1 Activity:

For this opening activity, accept reasonable responses to the K-W-L organizer.

3.1.2

Quick quiz on introduction to cells

1. Answers will vary but should include that cells are living, and the basic unit of life. Some students may also include prior knowledge about cells possessing a cell membrane, cytoplasm, ribosomes, and nucleic acids.

2. All living organisms are composed of cells.

        Cells are the basic unit of structure and function in organisms.

         All cells come from pre-existing cells.

3. Two categories of cell types: prokaryotic cells and eukaryotic cells

Activity: Cell observations and groupings

Cell set A: human cheek cells

Cell set B: onion cells (in mitosis)

Cell set C: Salmonella typhosus (bacterium)

Cell set D: Camphylobacter (a genus of bacteria)

Cell set E: rose petal cells

1. Observations should include: color, cell shape, any structure they may be able to identify, approximate number of cells present

2. similarities: overall cell shape, dark spot in cells (nucleus)

        Differences: color (due to stains used), size, number of cells

3. similarities: shape

         Differences: color, size, tails on Cell set C

4. cell set A and or cell set E because all of them have dark staining structures inside (nucleus/DNA)

5. Cell set C and/or Cell set D because of over shape and size differences, as well as the cells in these sets appear to lack internal structures

3.1.3

Microscope activity:

The activity provided is a very basic review of the light microscope. Once students are comfortable with using a microscope, consider having them view and sketch prepared slides of bacterial, plant and animal cells. Once sketched,students can label individual structures as they proceed through the lessons on prokaryotic and eukaryotic cells.

 Formative quick quiz for cell membrane KEY

1. What is a function of the cell membrane?

 a. to create nutrients for the cell

 b. to separate the inside of the cell from its environment

 c. to prevent any materials from getting into the cell.

 d. to allow the cell to move

 2. The cell membrane is mostly composed of which of the following?

 a. protein

 b. carbohydrate

 c. nucleic acid

 d. phospholipid

 3. Which statements regarding a cell membrane is true?

 a. It is composed of one type of molecule.

 b. It is needed to break down materials before they enter the cell.

 c. It protects the cell from being destroyed by bacteria.

 d. It contains chemical markers.
^[1]4. Identify which structure represents a phospholipid..

 a. structure 1

 b. structure 2

 c. structure 3

 d. structure 4

5. The most likely function of structure 3 is to:

 a. help the cell to breathe

 b. help the cell to attach to other cells

 c. digest nutrients

 d. allow materials to pass through

6. Identify structure 4.

 a. phospholipid

 b. carbohydrate

 c. glycolipid

 d. glycoprotein

7. This model of the cell membrane is referred to as the

 a. Dynamic equilibrium model

 b. Fluid mosaic model

 c. Phospholipid/protein model

 d. Integrated molecular model