ch1 Flashcards
Put these terms in order from most broad to most specific: phylum, species, kingdom, class, family, order, genus
kingdom, phylum, class, order, family, genus, species
which class contains the most living species?
insects (insecta)
species richness
the number of species present at a particular time.
species evenness
the relative abundance of each species
species evenness and richness mean?
both measures contribute to estimates of overall species diversity in a habitat - more species, and higher evenness among those species both indicate higher diversity in a habitat or ecosystem
What process drives the difference in vegetation between the western- and eastern-facing slopes of the Sierra Nevada mountains?
the rainshadow effect. As air masses move east from the pacific, they encounter the sierra nevada mountains and must rise over them. as air masses rise, the water vapor in them condenses into liquid water and rains out on the ‘front’ (windward) side of the mountains, which is the western side of the Sierra’s. As the air masses move down the back (leeward) side of the mountains, they produce dry conditions on the eastern side of the mountains. this difference in precitpation drives differences in the plant community in each habitat (more drought-tolerant plants on the eastern side, and less drought-tolerant plants on the western side)
How does the tilt of the Earth’s axis drive seasons?
because the earth’s axis is tilted, the northern and southern hemispheres do not always receive the same amounts of solar energy. from the march equinox to the the september equinox, the northern hemisphere is tilted towards the sun and recieves more solar energy than the southern hemisphere, and so this time of the year is the warmer seasons in the northern hemisphere, and the colder seasons in the southern hemisphere. from the september equinox to the march equinox, the southern hemisphere is tilted towards the sun, receiving more solar energy and making it the warmer seasons in the south and colder seasons in the northern hemisphere.
How do current concentrations of greenhouse gasses (carbon dioxide, methane, and nitrous oxide) compare to historic levels?
in all three cases, atmospheric concentrations of greenhouse gases have been increasing since we have been directly measuring them (1970’s for CO2, 1980s for methane, 1990’s for nitrous oxide). For CO2, we can look further back than our measurement records by studying ice cores in Greenland and Antarctica, which show that current CO2 levels are much higher than they were in the oscillations that occurred throughout the last ~800 years (which varied from ~180 to ~300ppm, compared to today’s value of over 420 ppm).
Using the Principle of Allocation, explain the concept of a trade-off.
the principle of allocation states “each organism has a limited amount of energy that can be used for all life purposes” and that “energy allocated to one function cannot be applied to another function” this means that organisms must make life directions about how to invest resources in different life functions (example: growth versus reproduction). the fact that an increased investment in one factor must be balanced by reduced invest in other factor(s) imposes trade-offs, whereby every decision has a benefit and a cost.
Give an example of a tradeoff involving adaptations or strategies for Resource acquisition:
root: shoot rations, optimal foraging theory, and photosynthetic pathways
Give an example of a tradeoff involving adaptations or strategies for Reproduction:
semelparity vs iteroparity and the tradeoff between offspring and number
evolution
relates to genetic changes in populations through time
ecology
focusing on how species and individuals interact with one another and with the environment
ecology & evolution
these relate to one another in that ecological interactions can drive evolutionary changes, and genetic changes can influence or alter ecological interactions
species diversity
in terms of the (D) value is a metric by which we compare diversity across ecosystems. the D value is calculated in respect to two important components: species richness (the number of species in the ecosystem) and species evenness (the similarity in relative abidance of each species)
Endotherm and ectotherm
these terms are the two ‘ends; of the continium of how organisms regulate body temp.
endotherm
endothermic organisms primarily regulate their temperature metabolically (though they will also often have some behavioural components as well).
ectotherm
regulate body temp behaviourally by relying on ecosystem temperatures
Weather and climate
weather is the short-term, current conditions in the atmosphere whereas climate represents long term averages in conditions or patterns
Rhizobia and mycorrhizae
Rhizobia and mycorrhizae are similar in that they both form mutualisms with plant roots in which they provide nutrients to the plant and receive sugar from photosynthesis in return. they differ in that Rhizobia are bacteria, while mycorrhizae are fungi; Rhizobia associate only with legumes while mycorrhizae associate with all types of plants
Fundamental niche and realized niche
the fundamental niche is the abiotic conditions and organisms can physically tolerate, and represents all the conditions under which the organisms might be found. the realised niche incorporates biotic interactions, and represents where the organisms will actually be found given its requirements for hosts/symbionts, or exclusion of some habitat by competition, predation etc
r-selected traits/organisms and K-selected traits/organisms
check lecture
hypertonic, hypotonic, isotonic
these all relate to osmoregulation, specifically which components
