Exam 1 Flashcards
What is ecology?
the study of the distribution and abundance of organisms
What is environment?
the sum of all the conditions surrounding us that influence life
What is environmental science?
the field that looks at interactions among human systems and those found in nature
What does it mean when we say systems?
by systems, we mean any set of interacting components that influence one another by exchanging material
What is an ecosystem?
a particular location on earth whose interacting components include living, or biotic, components and nonliving, or abiotic, components
What do environmental indicators help us do? What are the 5 environmental indicators?
they help us describe the current state of an environmental system; the 5 environmental indicators are biodiversity, food production, average global surface temperature and CO2 concentrations, human population, and resource depletion
What is sustainability?
the practice of living on Earth in a way that allows humans to use resources without depriving future generations of those sources
What is the primary focus of ecology?
explaining variation in the abundance, distribution, and diversity of species
What are 5 approaches ecologists use to answer questions about the natural world?
1) theoretical approaches: mathematical models
2) observational studies in the field
3) natural experiments
4) controlled experiments in the lab
5) experiments in the field
How does the physical environment influence an organism’s success?
It affects the ability to obtain energy and resources and it affects survival.
What is salinity?
concentrations of dissolved salts in water (e.g. NaCl, Mg, Ca)
Are freshwater vertebrates hypertonic or hypotonic to their environment? What are they always struggling to do?
Freshwater vertebrates are hypertonic to their environment. They are always struggling to get water out.
Are marine vertebrates hypertonic or hypotonic to their environment? What are they always struggling to do?
Freshwater vertebrates are hypotonic to their environment. They are always struggling to get water in.
What are acidity and alkalinity measured as? Define it.
They are measured as pH. pH is the log10 of the concentration of H+.
What do bases take up and give up? Acids?
Bases take up H+ or give up OH-, while acids are compounds that give up H+ to the solution.
How is acid rain formed and what does it do?
1) Acidic gases (CO2 and NO) are released into the environment from factories, etc.
2) Gases are carried by the wind and dissolve in rainwater to form acid rain.
3) Acid rain kills plant life, pollutes rivers and streams, and erodes stonework.
What do all organisms do? What do most organisms need?
All organisms respire. Most need oxygen.
What is hypoxia?
an area of low oxygen levels
Every organism has optimum levels of what?
salinity, pH, and oxygen
Why are metabolic reactions temperature sensitive?
because of the sensitivity of enzyme, which catalyze the reactions; most enzymes become denatured between 40 degrees and 70 degrees Celsius
What does temperature effect in cells?
the properties of cell and organelle lipid membranes and water loss
What is conduction? What is convection?
Conduction is when energy has to move physically from hot to cool (heating a metal rod). Convection is when you move energy through air (wind, fan).
How is the temperature of organisms determined?
by exchanges of energy with the external environment
What is latent heat transfer?
water absorbs heat as it changes state from liquid to gas
What is a pubescence?
hairs on leaf surfaces that reflect solar energy
What do stomata do?
they help reduce water loss and allow cooling
What are endotherms? What is their tolerance to temperature change?
They rely primarily on internal metabolic heat generation. They have a lower tolerance to temperature change (mammals and birds).
What are ectotherms? What is their tolerance to temperature change?
They primarily regulate body temperature through energy exchange with the environment. They have a higher tolerance to temperature change (reptiles).
What is heat exchange with environment a function of?
the organism’s surface area to volume ratio
How do ectotherms regulate body temperature?
by basking, migration, dormancy, and movement to local microsites (burrowing into the soil)
How do endotherms regulate body temperature?
They keep warm with things such as feathers, fur, and fat. They cool off by panting, sweating, hibernation, migration. and many other things.
What is water?
Water is the medium in which all biochemical reactions necessary for life occur.
How do plants deal with low water levels? (4)
They close the stomata, shed leaves in dry seasons, increase thickness of leaf cuticles (sclerophyllous plants), or increase the ratio of root biomass to the rest of the plant.
From what to what does energy flow?
Energy flows from producers to consumers to decomposers.
What is the first law of thermodynamics?
Energy can be transformed, but it is neither created or destroyed.
What is the equation for photosynthesis?
6CO2 + 6H2O –> C6H12O6 + 6O2
What happens when energy is transformed?
the quantity of energy remains the same, but its ability to do work diminishes
How do you calculate efficiency?
multiply the percent of energy that is not lost in a system; energy could be lost in the form of light, heat, etc.
What are autotrophs?
organisms that assimilate energy from sunlight or from inorganic compounds
What are heterotrophs?
Organisms that obtain their energy by consuming energy-rich organic compounds from other organisms. The energy ultimately comes from autotrophs.
Where does most of the biologically available energy on Earth come from?
photosynthesis
In the Calvin cycle, what does the dark reaction produce? Light reaction?
The dark reaction produces carbohydrates, while the light reaction produces ATP and NADPH.
What does system analysis show?
It shows how energy and matter flow in the environment.
What is the difference between open and closed systems?
In an open system, exchanges of matter or energy occur across systems, while in closed systems, matter and energy exchanges across system boundaries do not occur.
What does it mean when someone says a system is in a steady state?
the input of energy equals the output of energy
What is weather?
Weather refers to the short term conditions of the atmosphere in a local area. Conditions include temperature, humidity, clouds, precipitation, wind speed, and atmospheric pressure.
What is climate?
Climate is the average weather that occurs in a given region over a long period (typically over decades).