Midterm 2 review Flashcards
An organism displays the following characteristics:
- a bilayer of phospholipids
- is an extremophile
- a circular chromosome
- contains histone proteins
- a cell wall
- absence of organelles
It is:
An archaea
The growth of a bacterial population in the log-phase displayed on a log-scale is:
Linear
In the Long Term Evolutionary Experiment (LTEE) conducted by Dr. Richard Lenski, which of the following is (or are) important to show that the population has adapted to low-glucose utilization through the accumulation of beneficial mutations?
1) The measure of population growth (in the log-phase) in the presence of glucose
The comparison of growth rate to the ancestral population
2) The daily transfer of the population into a fresh glucose medium
3) The sequencing of the ancestral and the evolved populations
Concentration of a nutrient becomes a limiting factor:
When the graph begins to plateau
What characteristic makes the F factor a selfish-element?
The genes it contains code for the formation of a sex pilus, which facilitates its own transmission.
You wish to create and isolate a recombinant bacteria that carries an ampicillin-resistance gene. How would you proceed?
You perform a transformation of the bacteria with a plasmid containing the ampicillin-resistance gene, treat the transformed cells with ampicillin before picking a colony that survives.
Why is treating the transformed cells with ampicillin the right course of action?
d
What is one of the roles of the outer membrane in Gram (-) bacteria?
It protects against the entry of water-soluble antibiotics
Humans are:
Chemoheterotrophs
What are chemoheterotrophs?
Organisms that get their energy source and carbon source from organic sources. Chemoheterotrophs must consume organic building blocks that they are unable to make themselves. Most get their energy from organic molecules such as sugars.
What are phototrophs?
Organisms that capture light energy from the sun and convert it into chemical energy inside their cells.
What are chemotrophs?
Organisms that break down either organic or inorganic molecules to supply energy for the cell
What are photoheterotrophs?
Organisms that capture light energy to convert to chemical energy in the cells, but they get carbon from organic sources (other organisms).
What are photoautotrophs?
cells that capture light energy, and use carbon dioxide as their carbon source
What are chemoautotrophs?
cells that break down inorganic molecules to supply energy for the cell, and use carbon dioxide as a carbon source
The presence of bacteria in the gut of mammals is a good example of:
Commensalism
Bacteria living in their host gut provide their host with:
Vitamins
Sort the following steps of the origin of life in the correct chronological order
1) synthesis of organic monomers
2) transmission of self-replicating molecules (inheritance)
3) formation of protocells
4) synthesis of organic polymers
1 4 3 2
Which of the following is not a living organism?
One that is able to multiply
One that uses DNA as genetic material
One that needs a host to perform all of its metabolic reaction
One that does not react to a change in temperature
One whose number of cells does not increase over time
One that needs a host to perform all of its metabolic reaction
Which domain is thought to be responsible for the increase in atmospheric oxygen in the early history of life?
Domain bacteria
What are consequences of horizontal gene transfers?
The low resolution in the root of the Tree of Life
The acquisition of new metabolic pathways (metabolic flexibility)
True or False? The genetic code is identical in all living organisms without exception.
False
What is adaptive radiation?
A process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available
What is an isotopic half-life?
The amount of time it takes for 50% of a radioactive isotope to decay
Which came first during the history of organisms on earth?
The increase of atmospheric oxygen
What is the result/consequence of bilateral symmetry?
Development of a complex nervous system
What is the result/consequence of an exoskeleton?
New ecological relationships
What is the result/consequence of mitochondria?
Aerobic respiration in eukaryotes
What is the result/consequence of vascularization?
Colonization on land
What is the result/consequence of multicellularity?
Increase in size
What is convergent evolution?
Organisms in similar biomes evolve similar adaptations.
Why does convergent evolution occur?
Organisms converge in appearance and function since they are adapting to similar environments
What is important to remember about convergent evolution?
Organisms may look similar, but have different evolutionary history and mechanisms
Desert biomes experience ___ precipitation and ___ evapotranspiration.
Low, high
What is evapotranspiration?
the amount of water plants lose due to climate
Rain forests experience ___ precipitation and ___ evapotranspiration
High, high
List weaknesses of the biological species concept:
1) It cannot easily be applied to fossils
2) Quantifying reproductive barriers is hard when populations are allopatric
3) It is unclear/subjective how strong reproductive barriers must be
4) It doesn’t apply to asexual organisms
Explain how the biological species concept defines species
The biological species concept defines species as groups that actually or potentially interbreed and produce FERTILE offspring, and do not form offspring with members of other groups
