Download chapter2 review

Students can use BLM 0.0-6 Three-Column Table to complete
question 1.
2. (e)
3. (b)
4. (a)
5. (e)
6. Unicellular organisms are often called micro-organisms because they
are so small that they cannot be seen with the unaided eye. They can
only be seen with the help of a microscope.
7. (a) Three harmful effects of unicellular organisms:
• Some protists and bacteria cause diseases such as malaria and
conditions such as pneumonia, strep throat, and athlete’s foot.
• Some bacteria spoil food.
• Some bacteria and protists contaminate drinking water.
Time
45–60 min
Skills and Processes
The Chapter Review provides
an opportunity for students to
demonstrate their
understanding of and their
ability to apply the key ideas,
vocabulary, and skills and
processes.
Program Resources
BLM 0.0-9 Chapter Key Ideas
BLM 2.0 Chapter 2 Quiz
BLM 0.0-6 Three-Column
Table
Nelson Science Probe 8
Web site
www.science.nelson.com
Organ system Organs contained Tissues contained
respiratory trachea, lungs connective, nerve, blood,
muscle, epithelial
digestive intestines, esophagus,
stomach
connective, nerve, blood,
fat, muscle, epithelial
circulatory heart connective, nerve, blood,
fat, muscle, epithelial
(b) Three ways in which unicellular organisms are useful:
• Fungi can be used for making food (e.g., yeast for bread, wine,
and beer).
• Bacteria can be used for making food (e.g., buttermilk, cottage
cheese, and yogurt).
• Unicellular organisms help the body (e.g., production of
vitamin K in the intestines).
8. (a) The volume of cell A is 6 _m _ 6 _m _ 6 _m _ 216 _m3
The volume of cell B is 3 _m _ 3 _m _ 3 _m _ 27 _m3.
(b) The surface area of cell A is (6 _m _ 6 _m) _ 6 sides _ 216 _m2
The surface area of cell B is (3 _m _ 3 _m) _ 6 sides _ 54 _m2
(c) The ratio of surface area to volume for cell A is
216 _m2/216 _m3 _ 1 _m2/1 _m3
The ratio of surface area to volume for cell B is
54 _m2/27 _m3 _ 2 _m2/1 _m3
(d) The smaller cell should be better at absorbing nutrients and
removing waste because it has a 2:1 ratio of surface area to volume.
It has twice as much surface area as the larger cell, for the same
amount of volume.
9. Tissues, organs, and organ systems are required in large multicellular
organisms because individual cells depend on diffusion to obtain
nutrients and get rid of wastes. An individual cell that is surrounded
by layers of other cells would not be able to obtain nutrients by
diffusion directly from the source or get rid of wastes directly to the
outside. It needs some way to have nutrients delivered to it.
Specialized cells, tissues, and organs fulfill these special functions. An
individual cell in a large multicellular organism must also have a way
to communicate with the external environment, so that it can
respond appropriately. Specialization of cells, tissues, and organs
allows this communication to take place.
10. Cell specialization means that a cell is designed to perform only one
main function and does not have to use any energy for other
functions, as in a unicellular organism. Specialization allows a cell to
develop the specialized structures or take on a particular shape
required to do a job well. A cell that is required to do multiple jobs
must have a shape and structures that permit diversity and versatility.
11. Viruses are only active once they invade a living cell. The genetic
information from a virus directs the host cell to begin producing virus
particles. Once the virus particles are produced, the cell ruptures. This
releases a new batch of viruses that can attack other cells, which will,
in turn, produce more viruses. Living cells become virus factories.
12. An antibody produced against the influenza virus will not lock onto
a common cold virus. Each antibody has a specific shape to lock
onto the marker molecules of a specific invader, so it can only
lock onto this invader.
NEL