Unit 1: CELLS: Structure and Function
Week #1
7-1
Life is Cellular
Pgs169-173
Questions
1. What three statements make up the cell theory?
All living things are composed of cells. Cells are the basic units of structure and function in living
things. New cells are produced only from existing cells.
2.
What are the differences between prokaryotic cells and eukaryotic cells?
Prokaryotic cells are generally smaller and simpler than eukaryotic cells. Eukaryotic cells contain a
nucleus; prokaryotic cells do not. Eukaryotic cells generally contain dozens of structures and
internal membranes.
3.
Compare the processes used to produce a TEM and an SEM.
A TEM is produced by passing electrons through an extremely thin sample. A SEM is produced by
scanning a pencil-like beam of electrons over the surface of an object.
4.
What structures do all cells have?
A cell membrane and DNA
5.
How did the invention of the microscope help the development of the cell theory?
The microscope was essential in that development because it allowed biologists to observe cells in
living things.
Constructing a Chart
Make a three-column chart comparing prokaryotes with eukaryotes. In the first column, list the traits
found in all cells. In the second column, list the features of prokaryotes. In the third column, list the
features of eukaryotes.
7-2
1.
Cell Structure
Pgs 174-184
Questions
Describe the functions of the endoplasmic reticulum, Golgi apparatus, chloroplast and
mitochondrion.
Rough ER makes membranes and secretary proteins. Smooth ER makes lipids and helps in
detoxification. The Golgi apparatus modifies, sorts, and packages proteins and other materials from
the ER for storage or secretion. Chloroplasts capture the energy of sunlight and convert it into
chemical energy. Mitochondria convert stored chemical energy into compounds that the cell can use.
2.
Describe the role of the nucleus in the cell.
It is the control center of the cell.
3.
What are two functions of the cytoskeleton?
It helps the cell maintain its shape and also is involved in movement.
4.
How is a cell like a factory?
Answers may vary. A typical response will compare ribosomes to factory machines and the
cytoskeleton to a supporting structure. Students should also compare other organelles to various
parts of a factory.
5.
You examine an unknown cell under the microscope and discover that the cell contains chloroplasts.
What type of organism could you infer that the cell came from?
Students should infer that the organism would either be a plant or some other organism that carries
out photosynthesis.
Creating Artwork
Create a work of art – such as a painting or sculpture – depicting a cross section of a plant cell or an
animal cell. Include all the different organelles described in this section that would be found in that
type of cell. Label each organelle in your artwork.
7-3
1.
Transport
Pgs 183-189
Questions
Describe the functions of the cell membrane and cell wall.
The cell membrane regulates what enters and leaves the cell and also provides protection and
support. The cell wall provides support and protection for the cell.
2.
What happens during diffusion?
Particles tend to move from an area where they are more concentrated to an area where they are less
concentrated.
3.
Describe how water moves during osmosis.
Osmosis is the diffusion of water through a selectively permeable membrane.
4.
What is the basic structure of a cell membrane?
The basic structure is a double-layered sheet called a lipid bilayer, in which proteins are embedded.
5.
What is the difference between phagocytosis and pinocytosis?
In phagocytosis, extensions of cytoplasm surround a particle and package it within a food vacuole. In
pinocytosis, tiny pockets form along the cell membrane, fill with liquid and pinch off to form vacuoles
within the cell.
6.
What is the main way that active transport differs from diffusion?
Active transport requires the input of energy, but diffusion does not require additional energy.
Homeostasis
What is the relationship between active transport and homeostasis? Give one example of active
transport in an organism, and explain how the organism uses energy to maintain homeostasis.
7-4
1.
Cell Diversity
Pgs 190-193
Questions
In what kinds of organisms is cell specialization a characteristic?
Multicellular organisms have cell specialization.
2.
List the levels of biological organization in multicellular organisms from most simple to most
complex.
Individual cells, tissues, organs and organ systems
3.
How are unicellular organisms similar to multicellular organisms?
Both unicellular and multicellular organisms grow, respond to the environment, transform energy
and reproduce.
4.
Using what you know about the ways muscle moves, predict which organelles would be most
common in muscle cells.
Muscle cells have a large number of mitochondria, because mitochondria release energy from stored
food molecules and muscle cells need great amounts of energy to do the tasks they do.
Using Analogies
Use an organized area in your life – such as school, sports, or extracurricular activities – to construct
an analogy to explain how the levels of organization in that chosen area can be compared with those
of living organism.
Week#2
10-1
Limits to Growth
Pgs 241-243
Questions
1. Give two reasons why cells divide.
The larger a cell becomes, the more demands the cell places on its DNA and the more trouble the cell
has moving enough nutrients and wastes across the cell membrane.
2.
How is a cell’s DNA like the books in a library?
The information that controls a cell’s function is stored in DNA, just as information needed by the
public is stored in the books of a library. A cell’s DNA, then, is a “genetic” library.
3.
As a cell increases in size, which increases more rapidly, its surface area or its volume?
Its volume
4.
Calculate the surface area, volume, and ratio of surface area to volume of an imaginary cubic cell
measuring 4 cm on each side.
The surface area is 96 cm2, the volume is 64 cm3, and the ratio of surface area to volume is
96/64 = 3 : 2.
Cellular Basis of Life
Select two cell organelles and describe how their functions might be impaired if the cell were to
become too large. A review of Chapter 7 may help you with this task.
10-2
Cell Division
Pgs 244-249
Questions
1. Name the main events of the cell cycle.
A cell grows, prepares for division, and divides to form two daughter cells.
2.
Describe what happens during each of the four phases of mitosis.
Students should describe what happens during prophase, metaphase, anaphase and telophase, as in
Figure 10-5.
3.
Describe what happens during interphase.
Students should describe what happens during the G1 phase, S phase and G2 phase.
4.
What are chromosomes made of?
DNA, which carries the cell’s coded genetic information and proteins.
5.
How do prokaryotic cells divide?
A prokaryotic cell first replicates its genetic information before cell division begins. In most
prokaryotes, the rest of the process of cell division is a simple matter of separating the contents of
the cell into two parts.
6.
How is cytokinesis in plant cells similar to cytokinesis in animal cells? How is it different?
Cytokinesis is the division of the cytoplasm in both types of cells. The difference is that in plant cells
a cell plate forms midway between the divided nuclei.
Creative Writing
Suppose you were small enough to hitch a ride on a chromosome located in a plant cell that goes
through mitosis and cytokinesis. Describe what you would see happening during each phase of the
process.
10-3
1.
Regulating the Cell Cycle
Pgs 250-252
Questions
What chemicals regulate the cell cycle? How do they work?
Cyclins regulate the timing of the cell cycle in eukaryotic cells. Cyclin may cause a mitotic spindle to
form and trigger cell division.
2.
What happens when cells do not respond to the signals that normally regulate their growth?
Such cells, called cancer cells, divide uncontrollably and form masses of cells called tumors that can
damage the surrounding tissues.
3.
How do cells respond to contact with other cells?
Normal cells respond by not growing.
4.
Why can cancer be considered a disease of the cell cycle?
The cell cycle is the series of events that cells go through as they grow and divide, and cancer is a
disorder in which some of the body’s cells lose the ability to control growth.
5.
Write a hypothesis about what you think would happen if cyclin were injected into a cell that was in
mitosis.
A typical hypothesis might suggest that cyclin would have no effect because the cell was already in
mitosis.
Problem Solving
Imagine that you are developing a drug that will inhibit the growth of cancer cells. Use your
knowledge of the cell cycle to describe how the drug would target and prevent the multiplication of
cancer cells. Use the Internet to compare your anticancer drug with those currently in use.
40-4
1.
Cancer
Pgs 1052-1054
Questions
Describe the environmental factors that affect your health.
Students should describe air and water quality, poisonous wastes in landfills and exposure to solar
radiation.
2.
Name three things you can do to maintain your health.
Any three of the following: eating a healthful diet, getting enough exercise and rest, abstaining from
harmful activities, and having regular checkups.
3.
List some of the causes of cancer.
Cancers are caused by defects in the genes that regulate cell growth and division. These defects may
be inherited or caused by viruses, or they may result from mutations in DNA produced by radiation
or chemicals.
4.
Why are regular medical checkups and self-examinations important?
Regular medical checkups and self-examinations are important for detecting problems early so that
there is a better chance of treating them successfully.
5.
Should cancer be considered an infectious disease? Explain your answer.
Most cases of cancer are not infectious. However, cancer-causing viruses can be passed from person
to person.
Cellular Basis of Life
Recall the cell cycle from Section 10-2. In which phase do you think cells would be most vulnerable to
damage from radiation? Explain your choice. What characteristic of cancer cells might make them
especially vulnerable?