Bio 173 final Flashcards
Dependent variable
affected in response to the independent variable.
Ex. enzymatic activity of catalase
Independent variable
Manipulated/ Changed by researchers
not changing
positive controls
variable with known effect, expect a specific effect
negative control
no treatment, control/placebo, no effect
hypothesis
A testable statement that provides a possible explanation for a phenomenon. It is usually based on prior knowledge, observations, or theories.
Example: Catalase in potatoes requires Fe to function OR Fe is a cofactor for catalase.
prediction
A prediction is a specific forecast about the outcome of a study or experiment based on a hypothesis. It states what you expect to happen if the hypothesis is correct. An if-then statement, of what you expect to observe if your hypothesis is true. “If the level of sunlight increases, then the rate of photosynthesis will increase, resulting in more oxygen production.”
why are freezer stocks prepared
preserved the bacteria for longterm storage, used to make new probiotics during clinical trial
three steps of each cycle in PCR
denaturation, annealing, extension
PCR cocktail (master mix) component and functions of each
“Tiny primers need buffers too”
T - Taq Polymerase (heat-stable enzyme that extends DNA from the primers).
P - Pair for Primers (DNA or RNA to start DNA synthesis).
N - Nucleotides (building blocks of DNA).
B - Buffer (maintains pH for optimal enzyme activity).
T - Thermocycler (device to cycle temperatures and melt DNA)
positive control in PCR
shows your setup works
negative control in PCR
SHOULD have no result
if there is a result, contamination present - unwanted DNA in reagents or something is in your sample accidentally
scientific method
Question→Hypothesis→Experiment→Data→Conclusion
evolution and descent with modification
Change in genetic composition in a population over time (does not happen in an individual)
natural selection
Changes in genetic composition and gene frequencies in a population over time favor one that is more advantageous, species with the specific gene frequency are more likely to survive and reproduce - making it more prominent in the gene pool and population. Advantageous variations will eventually accumulate in the population, and the less favorable will diminish.
macroevolution
new life forms derived from older forms of life (birds from dinosaurs)
Law of succession
living organisms in a region will resemble fossils in the SAME region - fossils will appear in layered strata (rocks) with predictable sequence all around the world
anatomical homologs
structure that was evolutionarily derived from a single feature in an ancestor - an inherited PHYSICAL feature from an ancestor
molecular homology
similarities between species on a DNA/molecular level from an ancestor
convergent evolution
When organisms that are not closely related evolve similar behaviors or features, often as solutions to a common problem (similar body shapes, color patterns, behaviors)
microevolution
occurs over generations, short time scales
artificial selection
when humans take steps to amplify a “desirable trait” in animals and plants in future generations (like dog breeds, colors of flowers, scents of plants)
antibiotic resistance in bacteria
Antibiotic resistance occurs when bacteria mutate, survive antibiotics, and multiply, making treatments ineffective—a major threat to humanity.
vestigial structure
structures that have no apparent function and appear to be residual parts from a past ancestor (pelvic bone of a snake, our appendix and wisdom teeth)
speciation
occurs when a group within a species separates from other members of its group (a physical barrier) and develops its own unique characteristics (genetic drift)
