BIOD 101 MODULE 4 KEY CONCEPTS AND
BIOLOGY REVIEW NOTES 2026
◉ Bacteria with rod-shaped cells connected end-to-end are called
_________. Answer: bacilli
◉ Binary fission produces __________. Answer: two genetically
identical bacterial cells
◉ What do the following groups of organisms have in common:
methanogens (methane-producing organisms), halophiles (salt-
loving organisms), and thermophiles (heat-loving organisms)?
Answer: They are all archaea.
◉ Which one of the following soil-borne organisms can convert
atmospheric nitrogen gas into ammonium and other nitrogen
compounds that can be taken up and used by plants? Answer:
Nitrogen-fixing bacteria
◉ How does a bacterial cell obtain new DNA during the process of
transformation? Answer: Naked DNA from the surrounding
environment is taken up by a bacterium.
,◉ Which eukaryotic structures are thought to have been the result
of extensive inward folding of the plasma membrane of an ancestral
prokaryotic cell? Answer: The endoplasmic reticulum
◉ Protists are ___________. Answer: all eukaryotic
◉ How long ago did the first humans appear on earth? Answer: 2.5
million years ago
◉ The introduction of smallpox to the Americas by Europeans in the
colonial era devastated populations of Native Americans. However,
now very few people are vaccinated against the smallpox virus.
Why? Answer: Smallpox virus has been eliminated from the earth by
vaccination of most of the people alive today.
◉ The outer protein coat of a virus is called the ______________.
Answer: capsid
◉ Patients with advanced AIDS often die from infections that do
little harm to healthy people. Why? Answer: HIV infects and destroys
the helper T cells of the immune system.
◉ Which of the following pathogens causes mad cow disease?
Answer: A prion
,◉ Which of the following is NOT a characteristic of living things?
Answer: creating energy
◉ Homeostasis is a living organism's Answer: ability to maintain
constant internal conditions even when environmental conditions
change.
◉ Which of the following can be found in bacteria, but not viruses?
Answer: a cell membrane
◉ Viruses are Answer: not alive because they are not made of cells
and require a host cell for reproduction.
◉ Which of the following statements about viruses is FALSE?
Answer: The widespread use of antibiotics has led to resistant
strains of viruses.
◉ Why is combination drug therapy for HIV/AIDS less likely to lead
to resistance than single drug therapy? Answer: The likelihood of
one virus spontaneously mutating to be resistant to several different
drugs at the same time is extremely small.
Submit
◉ Suppose you were in charge of sending an unmanned space probe
to a new planet in search of life. The probe would be able to collect
, and test samples and make observations, but the planet is too far
away for the probe to be able to bring samples back to Earth. The
probe is small and would only be able to run a few tests, so you want
to pick a test for evidence of life that is broad enough to incorporate
all forms of life as we know it. Which one of the following tests
would be the best to use in this situation? Answer: a test for the
presence of cells that contain DNA
◉ Fungi are multicellular decomposers that obtain nutrients by
_____________. Answer: extracellular digestion
◉ What is the primary component of fungal cell walls? Answer:
Chitin
◉ In what way are plants similar to algae? Answer: Both can do
photosynthesis.
◉ Which of the following components is part of a plant's shoot
system? Answer: Flowers
◉ Fungicides are used to treat fungal diseases of plants. However,
experts have warned gardeners that application of a fungicide can
sometimes kill the plant as well as the fungal disease. Propose an
explanation for how this might happen. Answer: Fungicides might
kill fungi that are part of the plant's mycorrhizae.
BIOLOGY REVIEW NOTES 2026
◉ Bacteria with rod-shaped cells connected end-to-end are called
_________. Answer: bacilli
◉ Binary fission produces __________. Answer: two genetically
identical bacterial cells
◉ What do the following groups of organisms have in common:
methanogens (methane-producing organisms), halophiles (salt-
loving organisms), and thermophiles (heat-loving organisms)?
Answer: They are all archaea.
◉ Which one of the following soil-borne organisms can convert
atmospheric nitrogen gas into ammonium and other nitrogen
compounds that can be taken up and used by plants? Answer:
Nitrogen-fixing bacteria
◉ How does a bacterial cell obtain new DNA during the process of
transformation? Answer: Naked DNA from the surrounding
environment is taken up by a bacterium.
,◉ Which eukaryotic structures are thought to have been the result
of extensive inward folding of the plasma membrane of an ancestral
prokaryotic cell? Answer: The endoplasmic reticulum
◉ Protists are ___________. Answer: all eukaryotic
◉ How long ago did the first humans appear on earth? Answer: 2.5
million years ago
◉ The introduction of smallpox to the Americas by Europeans in the
colonial era devastated populations of Native Americans. However,
now very few people are vaccinated against the smallpox virus.
Why? Answer: Smallpox virus has been eliminated from the earth by
vaccination of most of the people alive today.
◉ The outer protein coat of a virus is called the ______________.
Answer: capsid
◉ Patients with advanced AIDS often die from infections that do
little harm to healthy people. Why? Answer: HIV infects and destroys
the helper T cells of the immune system.
◉ Which of the following pathogens causes mad cow disease?
Answer: A prion
,◉ Which of the following is NOT a characteristic of living things?
Answer: creating energy
◉ Homeostasis is a living organism's Answer: ability to maintain
constant internal conditions even when environmental conditions
change.
◉ Which of the following can be found in bacteria, but not viruses?
Answer: a cell membrane
◉ Viruses are Answer: not alive because they are not made of cells
and require a host cell for reproduction.
◉ Which of the following statements about viruses is FALSE?
Answer: The widespread use of antibiotics has led to resistant
strains of viruses.
◉ Why is combination drug therapy for HIV/AIDS less likely to lead
to resistance than single drug therapy? Answer: The likelihood of
one virus spontaneously mutating to be resistant to several different
drugs at the same time is extremely small.
Submit
◉ Suppose you were in charge of sending an unmanned space probe
to a new planet in search of life. The probe would be able to collect
, and test samples and make observations, but the planet is too far
away for the probe to be able to bring samples back to Earth. The
probe is small and would only be able to run a few tests, so you want
to pick a test for evidence of life that is broad enough to incorporate
all forms of life as we know it. Which one of the following tests
would be the best to use in this situation? Answer: a test for the
presence of cells that contain DNA
◉ Fungi are multicellular decomposers that obtain nutrients by
_____________. Answer: extracellular digestion
◉ What is the primary component of fungal cell walls? Answer:
Chitin
◉ In what way are plants similar to algae? Answer: Both can do
photosynthesis.
◉ Which of the following components is part of a plant's shoot
system? Answer: Flowers
◉ Fungicides are used to treat fungal diseases of plants. However,
experts have warned gardeners that application of a fungicide can
sometimes kill the plant as well as the fungal disease. Propose an
explanation for how this might happen. Answer: Fungicides might
kill fungi that are part of the plant's mycorrhizae.
