C H A P T E R
12
R E V I E W
Chapter Expectations
Language of Biology
Briefly explain each of the following points.
Write a sentence using each of the following words or
terms. Use any six terms in a concept map to show
your understanding of how they are related.
• Archaea are prokaryotes that live in extreme
environments. (12.1)
• Bacteria may be classified by their shape.
(12.2)
• Bacteria are either Gram-positive or
Gram-negative. (12.2)
• Bacteria may be autotrophs or heterotrophs;
phototrophs or chemotrophs. (12.2)
• Bacteria reproduce asexually by binary
fission and sexually by conjugation. (12.2)
• Bacteria are an essential part of ecosystem
processes such as chemical cycles and food
chains. (12.2)
• Protists may be classified as animal-like,
plant-like, or fungus-like. (12.3)
• Protozoa are classified in four phyla based
on their methods of locomotion. (12.3)
• Algae are classified into six phyla based on
their type of pigment and whether they are
unicellular or multicellular. (12.3)
• Fungus-like protists consist of slime moulds
and water moulds. (12.3)
• Fungi are heterotrophs. (12.4)
• Fungi may reproduce sexually or asexually.
(12.4)
• Fungi are classified in four major groups.
(12.4)
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
methanogens
halophiles
thermoacidophiles
cocci
bacilli
spirilli
diplostaphylostreptogram-positive bacteria
gram-negative bacteria
binary fission
conjugation
pili
plasmids
endospores
antibiotics
cyanobacteria
protozoa
algae
slime moulds
water moulds
pseudopodia
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
cilia
sporozoites
gametocytes
saprotrophs
plasmodium
sporangia
pseudoplasmodium
hyphae
mycelium
septa
extracellular digestion
haustoria
mycorrhiza
fragmentation
zygospores
stolons
rhizoids
sporangiophores
basidiocarps
basidiospores
basidia
asci
conidia
UNDE RSTAN DIN G CON CEPTS
1. Describe a characteristic that allows archaea to
survive in extreme environments.
5. Sketch a diagram showing the life cycle of the
malaria-producing sporozoan Plasmodium vivax.
2. In your notebook, state whether each of the
following statements is true or false. If the
statement is false, explain why.
(a) Most bacteria cause diseases.
(b) There are three main shapes of bacterial
cells.
(c) Gram-negative bacteria have thick cell walls.
(d) Bacterial cells can reproduce by mitosis but
not meiosis.
6. (a) What is an advantage of sexual
reproduction over asexual reproduction?
(b) Why is sexual reproduction the preferred
reproductive method of many protists when
environmental conditions are unfavourable?
3. Explain why the Kingdom Protista might be
considered an artificial taxon.
4. What characteristics do algae have in common
with plants?
7. Why are red algae found at greater depths in
the ocean than brown or green algae?
8. In what way do slime moulds resemble
(a) fungi, (b) plants, (c) protists?
9. Describe the difference between plasmodial
slime moulds and cellular slime moulds.
10. How do fungi obtain their food? Describe the
process in detail for one type of fungus.
Mostly Micro-organisms • MHR
459
11. A mushroom is only a small part of a fungus.
Explain what the bulk of a club fungus consists
of. What is the function of a mushroom in the
life cycle of the fungus?
16. What shape is Pneumococcus, the organism
that causes bacterial pneumonia?
12. What argument could you use to support the
idea that archaea were the first kinds of
organisms on Earth?
17. In coastal areas of Canada where shellfish are
harvested for human consumption, local
authorities monitor the populations of
dinoflagellates in the water during the
harvesting season. Why do they do this?
13. Many unicellular green algae have flagellae and
are able to swim. What is the advantage of
movement to these plant-like protists?
18. What evidence might you find in a limestone
cliff that tells you the rock material it is made
of originated in the ocean?
14. Name three ways in which a protozoan
resembles a human and three ways in which
it differs from a human.
19. Fish may be preserved from spoiling by adding
salt. Fruits may be preserved by adding sugar.
Explain how salt and sugar protect foods from
invasion by bacteria.
15. What characteristics of bacteria make them
useful tools for genetic engineers?
20. When might you deliberately eat (a) bacteria,
(b) fungi, and c) algae?
IN QU IRY
22. You have designed an experiment to show that
mould spores landing on a favourable surface
will germinate and produce hyphae. You have
placed two slices of bread on a plate for several
hours, and then sealed them into plastic bags
and put the bags into the dark. Complete the
procedure for this experiment. How long
would you wait before checking the bread?
What would you look for? Would you check
both slices at the same time? What data would
you collect? Create a data table showing results
from your two pieces of bread if (a) conditions
were not adequate to support the growth of
mould, and (b) conditions were adequate to
support the growth of mould.
23. In an experiment, a species of freshwater
protozoa was observed to study its behaviour
in different circumstances. Water, vinegar, and
sugar water were added to the protozoan’s
environment while the temperature stayed the
same. Answer the following questions
concerning the experiment.
(a) What was the control situation?
(b) What were the variables in the different
trials?
(c) Write a hypothesis that might go with this
experiment.
460
MHR • Diversity of Living Things
24. During an ecology field trip, a group of
students collected data about unicellular algae
at a site in the middle of a pond. They
measured the number of cells in the water a
various depths. They produced the following
graph based on their data.
Locations of Diatoms
Location of highest
concentration of diatoms
21. Design an experiment that could help you
decide if a particular type of bacteria could
grow in anaerobic conditions. Be sure to
include a control and to list the different
variables you would use.
Surface
50 cm
100 cm
12 A.M.
12 P.M.
12 A.M.
12 P.M.
Time
Use the graph to answer the following
questions.
(a) At what time were the highest
concentrations of diatoms at the surface?
(b) At what time were the highest
concentrations of diatoms about half a
metre below the surface?
(c) Why might the diatoms show the pattern
found by the students?
COMMU N ICATIN G
25. Construct a table comparing the characteristics
of archaea and bacteria. Use the information
from your table to describe one way in which
these organisms are similar and one way in
which they are different.
26. A museum has a collection of four algae
specimens which they need to classify to
display in an exhibit. Two of the algae have
chlorophyll a and b and two have chlorophyll
a and c. Two of the algae are unicellular and
two are multicellular. Both the unicellular
algae have flagellae. Based on this information,
name the four different groups to which the
algae belong, listing the identifying
characteristics beside each.
27. There are approximately 85 000 species of
fungi presently named in the world and
30 000 of these are sac fungi. Using these data,
calculate the percentage of fungi that are sac
fungi. If there are 25 000 species of imperfect
fungi, 25 000 species of club fungi,
1500 species of zygospore fungi, and
20 000 species of lichens, create a pie chart
showing the relative sizes of these groups. For
the purposes of this question, include lichens
as a type of fungi.
M A KIN G CON N ECTION S
28. There are many products on the market such as
soaps, hand lotions, and bathroom cleansers,
that claim to be anti-bacterial. Do you believe it
is a good idea to rely on these products to keep
our homes and bodies free of harmful bacteria?
Explain your answer, supporting it with
information about bacterial resistance. Based
on your answer, create a poster to give
information about these products to consumers
at grocery stores.
29. What precautionary steps can be taken to
prevent food poisoning? Create a checklist that
consumers could use to ensure the food they
are eating is safe from dangerous bacterial
infection.
30. The American chestnut tree was once a
common deciduous tree in North America.
Unfortunately, it has become increasingly rare
as a result of a disease called chestnut blight
caused by the fungus Cryphonectria parasitica.
The spores of the fungus germinate on the bark
of the chestnut tree, and the hyphae spread
underneath the bark. The spores of
C. parasitica are carried by the wind, or
passively on birds and insects, to other trees,
which then become infected. The Japanese
chestnut tree is somehow chemically resistant
to chestnut blight. You are a scientist reviewing
ideas to reduce infection of American chestnut
trees. One solution is to apply fungicide on the
bark of chestnut trees. Based on your
knowledge, why is this not likely to solve the
problem? Suggest a solution that involves
biotechnology and the Japanese chestnut tree.
31. A tiny bacterium called Mycobacterium
tuberculosis causes the often fatal disease
tuberculosis (TB) in humans. TB, which attacks
the lungs, was thought to be almost eradicated
from North America, but in recent times this
disease is making a comeback. The bacterium
is easily passed between people. As social
problems such as homelessness increase,
people are crowding in shelters in larger and
larger numbers. As well, many strains of the
bacteria are becoming resistant to antibiotics.
Some people feel that new technology is the
answer to this disease. Science and technology
should produce new medicines, and discovering
these drugs should be a priority to the medical
community. Others feel that prevention is the
solution. Society must eliminate conditions
that support passing the bacteria, and ensure
that infected people finish prescribed
medications. Write an essay about your ideas
concerning this problem. What do you feel the
priorities should be? Outline a strategy to deal
with the rise in cases of TB in Canada.
32. In the 1800’s, malaria was a relatively common
disease in parts of North America. One
approach to fighting the incidence of malaria
was to fill in swampy and marshy areas.
Explain why this would make a difference in
the prevalence of the disease. If this is a
successful method to fight malaria, why is this
approach not being taken in areas of the world
where malaria still exists?
Mostly Micro-organisms • MHR
461