Transcript Interactive questions: Viruses, bacteria and fungi

INTERACTIVE
MULTIPLE CHOICE
QUESTIONS
Viruses, Bacteria and Fungi
The answers are provided.
Explanations of why the alternatives
are unsatisfactory are also offered
These multiple choice questions are similar to the ones set
by the GCSE and IGCSE Examination Boards except that,
in some cases, there may be more than one acceptable
answer.
For this reason, even if you select a correct answer at your
first attempt, it is worth looking at all the alternatives
(a) to see if there is a better answer and
(b) to see why some of the alternatives are unacceptable.
First slide
Question 1
Which of the following are characteristics of a virus?
(a) Respiration
(b) Growth
(c) Excretion
(d) Reproduction
Question 2
No
Viruses do not respire
No
Viruses do not grow but they do reassemble
themselves in the host’s cell
No
Viruses do not excrete
Yes
Viruses do reproduce inside the host’s cell. Their DNA (or
RNA) replicates and they assemble new protein coats
using the host’s resources
Question 2
Viruses can reproduce only…
(a) at certain temperatures
(b) inside a living cell
(c) in dry conditions
(d) inside bacteria
Question 3
No
Reproduction of viruses is not dependent on temperature.
They will produce at any temperature which does not
damage their host’s cells
Yes
Viruses can reproduce only in the cells of their host organism
No
Unless the host is harmed by dry conditions, the virus
reproduces in the cytoplasm of the host’s cells
No
There are certain viruses, called bacteriophages, which
reproduce inside bacteria but this does not apply to all
viruses
Question 3
Which of the following diseases is caused by a virus?
(a) Influenza
(b) Tuberculosis
(c) Syphilis
(d) Sore throat
Question 4
Yes
Influenza (‘flu’) is caused by a virus
No
Tuberculosis is caused by a bacterium, Mycobacterium
tuberculosis
No
Syphilis is caused by a spirochaete bacterium, Treponema
pallidum
No
Sore throat is caused by a Streptococcus bacterium.
Question 4
A bacterial cell differs from a plant cell by having …
(a) no cell wall
(b) no central vacuole
(c) no nuclear membrane
(d) no cytoplasm
Question 5
No
A bacterial cell does have a cell wall but, unlike a plant cell
wall, it does not contain cellulose
Yes
A bacterial cell has no central vacuole
Yes
A bacterial cell has no nuclear membrane
No
A bacterial cell does have cytoplasm
Question 5
Most bacteria can be killed by …
(a) cooking
(b) refrigeration
(c) freezing
(d) canning
Question 6
Yes (within limits)
If the temperature is high enough and the cooking reasonably
prolonged, the majority of bacteria will be killed.
There will probably be a residual population of bacteria but not in
sufficient numbers to cause disease.
However, if the cooked food is left at room temperature, this
small population will multiply rapidly
No
Refrigeration at 4oC does not kill bacteria but slows down
their rate of reproduction so that the food remains safe for
longer periods
No
Freezing at about minus 18oC stops bacteria from reproducing
but does not kill them
Yes
Food is canned at high temperatures and pressures to kill
bacteria
Question 6
Which of the following is a bacterium?
(a) Penicillium notatum
(b) Candida albicans
(c) Plasmodium vivax
(d) Salmonella typhimurium
Question 7
No
Penicillium notatum is a mould fungus. It grows on
decaying fruit and other organic matter and is the source
of the antibiotic, Penicillin
No
Candida albicans is a yeast-like fungus. It causes a disease
called ‘thrush’
No
Plasmodium vivax is a protozoan parasite which
causes malaria
Yes
Salmonella typhimurium is a bacterium which causes
one form of food poisoning
Question 7
Which of the following diseases is caused by bacteria?
(a) Tinea
(b) The common cold
(c) Typhoid fever
(d) Diabetes
Question 8
No
Tinea is a skin infection caused by one of a number of fungal
parasites which cause inflammation between the toes (‘athletes’
foot’), on the scalp or in the pubic region
No
The common cold is caused by a virus, (a ‘rhinovirus’).
Yes
Typhoid fever is caused by a bacterium, Salmonella typhi.
No
Diabetes is not an infectious disease. It arises as a result of
either (a) a failure of the pancreas to produce sufficient insulin
or (b) an inability of the body to use insulin effectively
Question 8
A fungus is made up of …
(a) hyphae
(b) cells
(c) cytoplasm
(d) chitin
Question 9
Yes
Hyphae are the living, thread-like structures which form
a fungus
No
Fungi are made up of hyphae which have a wall, cytoplasm
and nuclei like plant cells but are in the form of long threads
No
A fungus is made up of hyphae which do contain cytoplasm,
but the fungus is not made solely of cytoplasm
No
Chitin is a component of the hyphal wall but the fungus is
not made up of chitin
Question 9
The drawing represents a
mushroom partly in section.
Which of the following
structures represents the
mycelium?
soil level
(a) A
A
C
B
(b) B
(c) C
(d) D
Question 10
D
No
This is the ‘cap’ of the mushroom
No
These are the ‘gills’ of the mushroom. They carry
the spores.
No
This is the mushroom’s ‘stalk’
Yes
This network of hyphae constitutes a ‘mycelium’
Question 10
Fungi have the potential to produce large numbers of
offspring by ...
(a) producing many seeds
(b) sexual reproduction
(c) producing fruits
(d) producing many spores
No
Fungi do not produce seeds
No
Fungi do have methods of sexual reproduction but they do
not result in the production of large numbers of offspring
No
Mushrooms, toadstools and bracket fungi are sometimes
called the ‘fruiting bodies’ of the fungus but this is a
misleading term. These structures produce spores.
Yes
Fungi produce a huge number of single-celled, microscopic
spores. Each one can produce a mycelium if it lands in a
suitable place, but only a tiny minority succeed.
The giant puffball produces trillions of spores which appear
as a brown dust cloud if you tread on it.
End of questions
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