unit 2 Flashcards
(34 cards)
During which eon did life
appear first?
2nd eon
Which gas was reduced in
the atmosphere before life
formed?
oxygen
- Discuss evolution of
metabolism
Primitive organisms may have been autotrophic or
heterotrophic
Landmarks in the evolution of metabolism
* Oxygenic photosynthesis.
* Carbon fixation.
* Nitrogen fixation.
RNA may have been first genetic material
Lipid bubbles could increase the probability of metabolic
reactions
* Leads to cell membranes.
Single-celled organism = first life-form
What is endosymbiosis?
Mitochondria and chloroplasts entered early eukaryotic
cells by endosymbiosis
* Mitochondria are the descendants of the parasite
Rickettsia, incorporated into cells early in the evolution of
eukaryotes
* Chloroplasts are derived from cyanobacter
Is a virus alive?
No
- What is the basic structure
of a virus?
Capsid, which is a protein sheets around the nucleic acid core
- Discuss host range and
tissue tropism
Host range is the types of organisms affected and tissue. Tropism is inside a host. The virus may only affect certain tissues.
- Compare and contrast the
lysogenic and lytic cycles.
Lysogenic
Virus isn’t immediately killed the affected. Cell phase allows for the virus supplication host data when host when the cell gets stressed it turns on genes necessary for the cycle to continue.
Lytic
Looks like all is steps
Attachment
Penetration where pierces the cell wall and inject it in the actual
Then synthesizes the material needed to create
Assembly all the components are assembled
Then it is released
What is the difference
between acute and
persistent viral infections?
With acute infection symptoms shows rapidly, and the host gets well or dies with persistent. It is latent or chronic and last a lot longer if not for the lifetime.
- Which process has caused
the changes in the flu virus
that cause pandemics?
Antigenic shift, Causes major changes in proteins and produces strains of viruses with novel combination of ha and na
- What is reverse
transcriptase?
Convert virus RNA two double-stranded DNA
- Why are herpes infections
never truly “cured”?
Because it’s a persistent viral infection. The virus can be in the host for years or for life
Which domain are many
extremophiles part of?
Archaea
What shape chromosome
do prokaryotes have?
Single Circular double-stranded DNA
- Discuss the key differences
in bacteria and archaea
They differ in four areas which are plasma, membranes, cell walls, and DNA replication and gene expression.
What part of a bacterial cell
does a gram stain test?
The cell wall
- What are the features that
can be found on the outside
of a prokaryote?
Capsule
S layer
Flagella
Pili
- Why do bacteria produce
endospores?
To protect itself basically, and this word developed a thick wall around their gum and some of the cytoplasm when they’re exposed to I environmental stress. Unconditioned to improve, they can garment in return to normal cell division.
- Discuss prokaryotic gene
transfer
There are three types of horizontal gene. Transfers transformation is an uptake of DNA from the environment, transduction is by viruses and conjugation is cell the cell contact
What causes a bacterial
mutation to spread through
a population so quickly?
Imitation to rise, spontaneously and through radiation and chemicals, it can increase its likelihood. It’s spread quickly through a population because how fast it came replicated so
- What are some ways
prokaryotes are beneficial
to their ecosystems?
Decomposition releasing dead organisms, atoms to the environment and fixation. Phasers fix carbon sugars ancient cyano bacteria added oxen to the air, nitrogen fixtures, reduce ammonia
- What process does bacteria
have to go through to cause
disease in another
organism?
The cause disease it must first gain to the body second colonize at the site of infection, three invade the immune system for spread other sides of the body damage by the production of toxins or triggering inflammatory responses
How is it hypothesized that
eukaryotic nuclei and ER
evolved?
The nucleus and the ER arose from the infoldings of a pre-prokaryotic cell membrane
- Why is classifying protists as
a whole group not
accurate?
Classify pros is a whole group is not entirely accurate because they don’t share. They united only because not fungi, not plants or animals so they’re classified by exclusion. They don’t belong to any group.
