Plant and Animal Cells

 10th/11th grade Biology

 3 class blocks (or ~ 4 hr, over 2 days)

 Students should understand the characteristics of living things

 Structure and function of plant, animal and prokaryotic cells.

 Introduction to DNA, cell division and mitosis.
 Lab activity - observing cells using the light microscope

• Students should be able to explain and apply cell theory

• Students should be able to describe the major components of a cell, including the cell membrane, cytoplasm, nucleus, ribosome, endoplasmic reticulum etc.

• Students should appreciate the differences between a plant and animal cell.

• Students should have a basic understanding of chromosomes, mitosis and cell division.
  

Lab activity: toothpicks, glass slides, iodine, coverslips, microscope

Mitosis activity: String, toothpicks, glue, markers, poster paper

Procedure

Opener

a. Do now - students read chapter on cells and living things using SQ3R method for 5-10 minutes. (Pg 35 - 38)  Teacher and students discuss SQ3R responses for 5-10 minutes. Teacher should use this opportunity to discuss spontaneous generation and pros and cons of this theory. Finally, highlight the contributions by various scientists over the years towards Cell Theory.  

b. Analogies -  Using the textbook, students come up with analogies comparing cell organelles to a factory (e.g., mitochondria is the power supply). Students practice asking each other questions (e.g., what is the control center of the cell?) to reinforce their understanding of the vocabulary.

Development

a. Lab activity - Students will have the opportunity to visualize plant (onion) cells and animal (human cheek) cells using a microscope. Students will practice mounting a sample and using the microscope using paper alphabets before moving on to real specimens. At the end of the lab, students will compare and contrast their observations with a plant cell vs. an animal cell.

Part I: Onion cells - Onion cells were mounted and stained by the teacher before the lab. Students will practice focusing the microscope and draw their observations using the 4x and 10x objectives. Students should take note of the cell morphology and identify organelles in the cell.

Part II: Cheek cells - Students make a smear of their own cheek cells on glass slides. They will then stain the cells and image them using the light microscope. Students will draw their observations using the 4x and 10x objectives. Students should take note of the cell morphology and identify organelles in the cell.

b. Mitosis activity - Students are introduced to cell division, specifically mitosis, and come up with mnemonics (e.g., "Plant My Apple Tree" for Prophase, Metaphase, Anaphase and Telophase) to aid them in remembering the various stages of mitosis. Students are each assigned one phase of mitosis and will use the provided materials to create a model of the cell and the arrangement of the chromosomes in that phase. 

Closure

a. Cell model - Students are given a Ziploc bag and will create a cell model containing at least 5 representative organelles using any materials they can find at home or in the school.

b. Cell crossword - As a review, students work individually or in small groups to complete a crossword puzzle reviewing cell structure and function.

Download Cell Crossword - PDF

  Students will be quizzed on the components of the cell and their ability to describe their function using an appropriate analogy. Students will be evaluated on their ability to independently create an accurate cell model using everyday materials. The best models will be displayed in the classroom.
For the lab, students should be able to compare and contrast their observations with an appropriate analysis and conclusion that demonstrates their understanding of the concepts and vocabulary.

   Cancer: Cancer occurs as a result of uncontrolled cell division. Students will research one type of cancer and present their findings in the form of an oral presentation to the class. Alternatively, discuss a case study with the class. 

 SQ3R reading method: http://www.collegeboard.com/student/plan/college-success/26666.html
Contemporary Biology: Exploring the Science of Life (Textbook)