Ultimate Test 2 Study Guide Flashcards
what kind of information do phylogenies provide?
they show the patterns of evolution and how species are related to each other through ancestry
on what infromation are phylogenies based?
based on data from morphology, DNA and development
Phylogenies are hypotheses based on data. What does that mean?
it means that it uses morphology, DNA and development to estimate evolutionary history
why are traits that are the result of convergent evolution misleading for making phylogenies?
they create the illusion of shared ancestry between distantly related organisms, masking their true evolutionary relationships
Why is it not appropriate to clssify life as either prokaryotes or eukaryotes?
it is an oversimplification because archea are more closely related to eukaryotes than bacteria
what do prokaryotes and archea have in common (3)
no nucleus or membrane-bound organelles, single-celled, reproduce by binary fission
why don’t we use the term prokaryote in classification?
it’s a paraphyletic group, meaning it doesn’t include all descendants of a common ancestor, and doesn’t accurately reflect the evolutionary relationships of Bacteria and Archaea
What do you think might explain the closer relationship between archaea and eukaryotes then between archaea and bacteria? (2)
shared genetic traits in RNA (rRNA) and the metabolic pathways are more similar to eukaryotes than bacteria
What is the relationship between the structure of cell walls in bacteria and their function?
Peptidoglycan, is a mesh-like structure that provides rigidity and strength which helps with holding shape and serving as a target for certain antibiotics
gram-positive bacteria have …
a single membrane
gram negative bacteria have…
double membranes
capsule definition
a sticky outer layer surrouunding the cell walls of many bacteria
capsule function (3)
more efficient adhesion, protection from dehydration, prevent invasion from pathogens
Endospores
dormant structures that help bacteria survive in unfavorable conditions
What is necessary for natural selection to occur in the experimental population in the Cooper and Lenski experiment? (3)
variation in traits, inheritance of those traits, and differential reproductive success (or fitness)
what is the source of variation in the cooper and leneski experiment?
mutations that increased the rate of mutation to cit+
what trait is favored in the cooper and linesky experiment?
the ability to use citrate
What are the sources of genetic diversity in bacteria? (3)
mutation, horizontal gene transfer and the movement of mobile genetic elements
what is the difference between horizontal transfer and vertical transfer of genes?
Vertical gene transfer involves passing genes from parent to offspring, while horizontal gene transfer is the transfer of genetic material between organisms that are not direct descendants
what are 3 implications of horizontal transfer of genes?
the rapid spread of antibiotic resistance, the evolution of new traits, and the emergence of novel species, particularly in prokaryotes
what are the 3 ways that horizontal transfer happens?
transformation (taking up DNA from the environment), conjugation (transferring DNA between cells via direct contact), and transduction (virus-mediated transfer of DNA
What types of resources can prokaryotes use to generate energy? (4)
light (phototrophs) or chemical compounds (chemotrophs), and carbon from carbon dioxide (autotrophs) or organic compounds (heterotrophs)
What features of archaea do you think has contributed to the delayed discovery of archaea? (3)
Morphological Similarity to Bacteria, Extreme Habitat Preference, Resistance to Standard Antibiotics
What are some of the roles that prokaryotes play in a functioning ecosystem? (3)
Decomposers (Nutrient Recycling), nitrogen fixation, and Oxygen Production (Photosynthesis)