Download Biology 1Pre-AP/GT - 2011 Unit 3: Cells

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Biology 1Pre-AP/GT - 2011 Unit 3: Cells/ Cell Processes
Chapters 7-10
A. 1. Recall and list the characteristics of living organisms. (chapter 1, page 16)
2. What is the cell theory? What are the basic points? (chapter 7)
3. Read the history of the discovery of the cell. Answer the following questions. Section 7-1
a. What scientist first used the microscope?
b. Which three scientists developed the cell theory? What were their contributions?
c. What scientist first observed tiny living organisms in water?
d. Approximately how many years have passed since the microscope was first used?
4. List the similarities and differences between prokaryotic and eukaryotic cells.
5. What is a virus and how is it different from living cells (page 478)? Sketch a virus (any virus) and label the
parts.
6. Label the handout of a plant and an animal cell. (class assignment)
7. Complete the chart/activity on the cellular organelles. (we will discuss this in class)
 Cell membrane
 Cytoplasm
 Ribosomes
 Nucleus
 Rough and smooth endoplasmic reticulum
 Golgi apparatus
 Chromosomes
 Nucleolus
 Mitochondria
 Chloroplast
 Lysosomes
 Cytoskeleton
 Centrioles (p.246)
 Flagella (p 473)
 Vacuole
 Cell Wall
8. What is meant by cell specialization?
9. All cells have many characteristics and functions in common, but in large multicellular organisms,
these cells take on specific functions. How does cell specialization allow for a more efficient and complex
organism?
10. Furthermore, cells join together to form tissues, which also have specific functions. What other
levels of organizations have biologists developed to describe this increase in complexity?
Describe each level (page 192-93).
11 .Distinguish between the terms unicellular and multicellular.
Activity #1: CELL COMPARISON ACTIVITY
Follow teacher instructions
Activity #2: OBSERVING DIFFUSION
Conduct the following procedure, record your observations, and discuss in your
conclusion what happened.
 Into a baggie, pour 50 ml of a starch solution.
 Completely seal the baggie to prevent leakage. Immerse it in a beaker filled with Lugol’s.
 Wait 20 minutes and record your observations.
 During the wait time, place a drop of Lugol’s on a piece of potato. Record your observations and note
that this is a positive test for starch.
 In your conclusion, discuss the results of what you have observed. Include the following points in your
discussion:
o What does the baggie represent?
o What happened inside the baggie and why?
o Why didn’t the same thing happen outside the bag?
o What was occurring with regard to the water?
B.
1. What is one of the most important functions of the cell membrane?
2. Sketch a small section of a cell membrane. Label the lipid bilayer, channel proteins, and marker proteins.
What are the functions of each?
3. What is concentration? p.183
4. Define diffusion.
5. What is equilibrium?
6. Define osmosis.
7. Describe the movement of water during osmosis in terms of solute concentration.
8. How will a plant cell react to a hypotonic solution? Animal cell?
9. Penicillin affects cell walls in bacteria causing them to become weak. What will happen when the bacteria
are placed in a hypotonic solution?
10. Compare figure 7-14 to figure 7-17? Explain how facilitated diffusion is different from simple diffusion.
11. Does the size of the molecule have anything to do with what moves across the cell membrane and what
doesn’t?
12. Are there any other factors that might have an impact on movement of molecules?
Activity #3: OBSERVING OSMOSIS
Activity #4: OSMOTIC EFFECTS ON LIVING CELLS (PLASMOLYSIS)
Complete the following procedure and record your results
 Place a leaf of Elodea on a glass slide. Add a drop of water and cover with a cover slip.
 Observe with the microscope and sketch on high power. Label as many cell parts as you can see.
 Add a drop of concentrated salt water using a piece of paper towel to “pull” off the water and pull in the
salt water. Observe under the microscope and sketch on high power. Label.
 In your conclusion, explain what happened. Include the following terms: hypotonic, hypertonic,
selectively permeable membrane, concentration gradient and plasmolysis.
C.
1. How do small molecules move against a concentration difference (low to high)? Refer to fig
7-19
2. Why are endocytosis and exocytosis considered forms of active transport?
3. How are endocytosis and exocytosis different? Sketch your answer.
4. What is the difference between pinocytosis and phagocytosis?
5. In summary, compare and contrast active transport with passive transport.
Activity #5: HOW ONE CELL BECOMES TWO – Mitosis
We have established that not all cells are alike in structure and function and we have also noted that cells can
group together to form tissues. Typically an organism begins as one cell and grows into a multicellular one. How
is this possible? In other words, how does an organism grow?
Part 1: You will be given a set of different cards. Study these cards and place them in a sequence that would
show how one cell becomes two. Then, with your lab group, write a description explaining in such detail that
another group would be able to place the cards in the proper order.
Part 2: Obtain a slide of an onion root tip. (Note that this is a tissue made of many cells.) Locate each of the
stages represented by the cards. Sketch each in your journal. Next observe computer images of whitefish cells
undergoing cell division. Compare to the onion cells. List the differences between animal and plant cells that are
undergoing this process.
D.
Chapter 10
1. Why do cells divide?
2. What is the cell cycle? Sketch the phases to show where mitosis fits into this.
3. In Activity #4 the process of one cell becoming two (mitosis) is seen as a nonstop event. Yet for study
purposes, it is divided into phases. Sketch and label the stages.
4. How do cells “know” when to undergo mitosis?
5. Under what conditions will the cell divide erratically? What is uncontrolled cell division called?
6. Read the article on page 253.
 What are stem cells?
 Why are they at the front of much research today?
 Explain the controversy that surrounds this area of study.