Ch 2 review Flashcards
What structures of a virus help it enter a host
cell and take over the cell’s reproductive
structures?
The protein coat that surrounds a virus is like a key to a door. Patterns on the viral coat unlock an entryway into a host cell
Some viruses also have outer membranes that merge with a host cell’s membrane, making it easier for the virus to infect the cell.
Archaea are a type of prokaryote. What
differentiates archaea from bacteria?
archaea don’t have peptidoglycan
they also live in some of the most extreme
environments on Earth, which may resemble conditions that existed on early Earth and are more complex than bacteria
Describe the process of binary fission
cells DNA duplicates –> cell begins to divide –>
produces 2 genetically identical daughter cells
Why is the term Harmful Algal Bloom a more
appropriate term for the phenomenon known
as a red tide?
the tide is not always red or associated with the sea
Scientists studying bacteria will often rely on
three major characteristics to classify bacteria.
Describe the importance of each
- cell shape: allows us to identify them by species
- cell wall structure: helps differ between archaea
and bacteria - motility: classified based on if they don’t move,
have flagella or use a corkscrew motion
to move
What is the taxonomic definition of a protist?
All eukaryotes that are not animals, plants, or fungi are classified as protists
What is the difference between the terms
“hyphae” and “mycelium”?
Hyphae are tiny threads of cytoplasm surrounded by a plasma membrane and covered by a cell wall
The hyphae of a single fungus typically branch as they grow, forming an interwoven mat called a mycelium
What feature of the avian flu virus makes
containing its spread more difficult than a
typical virus like the tobacco mosaic virus?
The avian flu virus can infect many different types of birds and mammals.
the protein coat of this virus is like a master key, unlocking many different types of cells.
Why do biologists often classify protists
according to “lifestyle”? What problems may be
associated with this type of categorization?
-the protist group is very diverse and it’s hard to find similarities between different protists
-some protists may act similar but aren’t alike at all
Suppose you are given a sample of pond water
and observe a single-celled organism with
the following characteristics: moves through
water with the aid of a long whiplike tail; is
green in colour; appears to have a number of
smaller structures within the cell. Identify the
organism. Be as specific as possible and justify
your reasoning
Euglena
-green
-has a flagellum
-photosynthetic (has structures)
Many bacteria and protists have the ability
to switch between sexual and asexual
reproduction. Why would this reproductive
strategy be successful for these organisms?
when conditions are unfavourable, they can switch between methods
Describe how conjugation offers a better chance
of success for an organism. Use a specific example.
In conjugation, two bacterial cells temporarily join
and directly exchange genetic material. Conjugation usually involves plasmids.
-genetic recombination
Suppose a person who has been exposed to
a virus has blisters on her arm that appear at
least once a year and seem to be associated
with some type of environmental trigger.
Does this virus exhibit a lytic or lysogenic
reproductive life cycle? Explain your answer
-lysogenic cycle
in the lysogenic cycle, an environmental change in
temperature or pH triggers the viral DNA to separate from the host DNA and start a lytic cycle
In which of the four fungi phyla does the fungus shown at the right belong (has a club)?
Club-shaped cell = Basidiomycota
