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RNR 316 > Exam 1 > Flashcards

Exam 1 Flashcards

1
Q

what is ecology?

A

the scientific study of the abundance and distribution of organisms in relation to other organisms and environmental conditions. “study of the house”

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2
Q

describe our ecological systems from smallest to largest

A

individual –> population –> community –> ecosystem –> biomes –> biosphere

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3
Q

define individual. what do they require and produce? provide an example

A

an individual has a membrane boundary that separates internal processes from the external environment. they require nutrients and energy and produce waste. lizard

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4
Q

define population. provide an example

A

all the members of a species in a given area at a given time. bighorn sheep in the Santa Catalina mountains.

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5
Q

individuals ______, populations ______. individuals are the unit of ________, while populations are the unit of ______.

A

adapt, evolve. natural selection, evolution.

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6
Q

define community. what is the research approach?

A

association of interacting populations defined by the nature of their interactions or the place in which they live. (boundaries are often artificially defined for research). research approach = species interactions and relative abundance and diversity of species living together

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7
Q

define ecosystem. what is the research approach?

A

assemblage of communities of organisms (biotic) along with their abiotic, physical and chemical environment. research approach = energy flow, nutrient cycling, and element pools (N2, O2 , C2)

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8
Q

define the biosphere, what is the research approach?

A

integrated system of all environments and organisms on earth. research approach = global study of air and water and how those influence individuals, populations, communities, and productivity

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9
Q

what is teleconnection?

A

distant ecosystems are linked together by exchanges of wind and water and by the movement of organisms.

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10
Q

what are the physical principles that govern ecology?

A

matter and energy cannot be created nor destroyed but can change form. (law of conservation of matter and energy)

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11
Q

when does a dynamic steady state occur?

A

occurs when the gains and losses are in balance.

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12
Q

define evolution and state the 3 mechanisms in which evolution can occur through.

A

evolution is a change in the genetic composition of a population over time. 1) natural selection 2) artificial selection 3) genetic drift (random chance).

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13
Q

define and describe the scientific method.

A

the scientific method is an iterative process of gaining knowledge. observations –> hypothesis –> test the hypothesis (w/ proper controls) –> revise hypothesis if unsuccessful or make additional predictions and test them

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14
Q

what is a genotype and a phenotype?

A

a genotype is the genetic makeup of an organism. a phenotype is the outward expression of environmental affects on an organism’s genotype.

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15
Q

define natural selection.

A

a change in the frequency of genes in a population through differential survival and reproduction of individuals that possess certain phenotypes.

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16
Q

evolution through natural selection has been around for ________ years

A

3.8 billion years

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17
Q

describe the process of evolution through natural selection.

A

1) individual’s will have varying traits within its species (mutations)
2) some of these variations are passed onto offspring (heritability)
3) individuals with better fitness are those with randomly generated variations that best suit their current environment
4) those individuals will pass more copies of their genes to the next generation and that phenotype will come to dominate

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18
Q

what are the three domains of life?

A

bacteria, archaea, and eukarya (over 1.6 million described species)

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19
Q

what are prokaryotes?

A

they were the first, single-celled bacterium and archaea (without distinct organelles) to inhabit earth. they can use sources of energy that most organisms cannot (H2S and N2 gas). cyanobacteria can photosynthesize.

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20
Q

what are eukaryotes?

A

organisms with distinct cell organelles that evolved from prokaryotes.

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21
Q

what is endosymbiosis?

A

mutualistic relationship between a host and an organism living within its body or cells that benefits both and improves fitness

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22
Q

what is the endosymbiosis theory?

A

one bacterium or archaea engulfed another bacterium, the engulfed bacterium became a mitochondria and this gave rise to all eukaryotes.

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23
Q

what is a habitat?

A

an area with a combination of resources (food, water, cover) and environmental conditions (temp, precipitation) where individuals of a given species settle, survive and reproduce. typically distinguished by physical features like dominant plant type.

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24
Q

what is a niche?

A

the range of abiotic and biotic conditions an organism can tolerate (function and position of a species in the environment)

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25
Q

can two species have the same niche?

A

no 2 species can have the same niche because each specie has unique phenotypes that determine the conditions it can tolerate. (otherwise, they will compete for resources until one has outcompeted the other)

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26
Q

what are the 3 types of ecological inquiries?

A

1) observational (maximizes realism)
2) experimental (maximizes precision)
3) theoretical (maximizes generality)

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27
Q

what percentage of Earth is covered in water? what is the percent breakdown?

A

71% of Earth’s surface is water; 97% ocean, 1% fresh water and 2% ice caps/glacier

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28
Q

5-25% of global freshwater use exceeds _______________________.
15-35% irrigation withdrawals exceed _______

A

long term accessible water
supply rates

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29
Q

what are the important properties of water?

A

1) high absorption of light energy
2) high specific heat (thermal, energy required to rais temp 1 degree celcius)
3) 800+ times dense as air
4) 55 times as viscous as air
5) important solvent of inorganic nutrients

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30
Q

describe how sunlight penetrates bodies of water

A

most solar radiation is absorbed within the upper meters; only the surface water is heated. deep water is very cold as <1% of light reaches the lower depths. hence, photosynthesis is restricted to near the surface (photic zone).

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31
Q

how have organisms adapted to waters’ high viscosity?

A

many larger organisms have evolved to have streamlined bodies that reduce the drag caused by the high viscosity. smaller organisms have evolved long, filamentous appendages that increase drag.

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32
Q

describe why water is a powerful solvent

A

water is a polar molecule (hydrogen bonding, partial negative charge) therefore, it attracts charged atoms or molecules (ions) which causes many substances to dissolve. (NaCl)

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33
Q

every mineral has an upper limit of solubility in water, known as _________

A

saturation. beyond saturation, minerals precipitate outside of water (calcium carbonate precipitates out and forms limestone).

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34
Q

explain how acid rain occurs

A

acid rain occurs when high concentrations of pollution from smoke is burned into the atmosphere, creating sulfur oxides and nitrogen oxides, which then react with water in the atmosphere and form sulfuric acid and nitric acid which are very powerful acid and solvent

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35
Q

explain how acid rain is a threat to freshwater

A

acid rain falls directly onto bodies of water which lowers the pH of the water. they also fall onto soils which draws out naturally occurring Aluminum from soils into watersheds, lakes, streams, oceans etc. this decreases the pH even more. Al in high concentrations is highly toxic for fish and invertebrate reproduction and has a negative effect on enzyme activity.

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36
Q

what are solutes?

A

dissolved substances in water.

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37
Q

what is osmosis?

A

(Passive transport across a semipermeable membrane.) the movement of water from low solute concentration to an area of high solute concentration until they’re both equal.

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38
Q

what is the semipermeable membrane?

A

membranes that allow only particular molecules to pass through; reduces free movement of solutes

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39
Q

what is osmoregulation?

A

the mechanisms organisms use to maintain a proper solute balance, including active transport.

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40
Q

what is active transport?

A

the movement of molecules through a membrane against a concentration gradient, from a region of low solute concentration to a region of high concentration. requires cellular energy to move. allows an organism to maintain a preferred concentration of solutes (specific to aquatic/marine organisms).

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41
Q

what is hyperosmotic?

A

when an organism has a higher solute concentration in its tissue than the surrounding water (ex: freshwater fish are saltier than water; osmotic gain of water; active mineral uptake (kidney’s process), urine to get rid of water)

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42
Q

what is hypoosmotic?

A

when an organism has a lower solute concentration in its tissue than the surrounding water (the water is saltier than inside of saltwater fish). fish drinks in water, losses water through its gills, but kidneys will be working to conserve as much water and get rid of salts

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43
Q

explain how road salt can be fatal for aquatic animals

A

road salt is put onto roads in winter –> much of that salt is washed away with precipitation into nearby ponds, lakes, streams etc., –> increases in salt concentrations cause major die-off in larval stages

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44
Q

how have mangrove trees faced challenges of salt balance?

A

mangrove trees maintain high concentrations of organic solutes in their roots to increase osmotic potential. mangroves have adapted to salt imbalances by being able to secrete excess salt from leaves and some exclude salts from roots by active transport

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45
Q

CO2 diffuses _____ through water. plants use CO2 _____ than it diffuses into leaf tissues.

A

slowly
faster

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46
Q

what is CO2 rapidly converted into when dissolved in water?

A

bicarbonate (HCO3-) or carbonate (CO3-) ions, which accumulate in massive quantities and can be used for photosynthesis. even when they’re abundant, they diffuse slowly and limit plant growth

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47
Q

what is the boundary layer?

A

a region of unstirred air or water that surrounds the surface of an object. removed gases from this region are slow to be replaced; this further limits carbon availability

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48
Q

what is the percent of oxygen in water? how have deep ocean organisms adapted to survive this?

A

1%
many organisms have low activity rates (metabolism is lower) which reduces O2 demand.

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49
Q

what is an example of a mutualistic relationship that helps the organisms adapt to their environment (in terms of low CO2 and O2 demands)

A

spotted salamander eggs living within algae cells. the eggs provide CO2 to the algae and the algae provides O2 to the eggs. eggs in algae hatched larger and faster

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50
Q

when an environment becomes completely depleted of O2, it is called what

A

anoxic or anaerobic. many microbes live in anaerobic environments by using other sources of metabolic energy (sulfur)

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51
Q

what is eutrophication?

A

the process by which excess nutrients (nitrogen + phosphorus) flow into an aquatic ecosystem, causing an algal bloom in photic zone. that algal bloom then all dies off, sinks and decays which depletes O2 and causes anoxic/anaerobic conditions. this hypoxia is fatal for fish and invertebrates and typically causes microbe and plant diversity to decline.

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52
Q

explain what happened in Toledo, Ohio (Aug 2014)

A

phosphorus fertilizer runoff from farmland and warm water causes a massive cyanobacterial bloom which produced neurotoxins that are toxic to people and animals. the decaying mats causes hypoxic conditions and the neurotoxins couldn’t be filtered out.

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53
Q

what is thermotolerance?

A

heat and biology interacting.

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54
Q

what is Q10 value?

A

the ratio of a physiological processing rate at one temperature to the rate of that same process when the temperature is 10 degrees Celsius cooler. (usually 2-4 times difference)

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55
Q

heated proteins and other biological molecules become _____ stable, _____ function properly, and may _______ (change shape)

A

less
may not
denature

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56
Q

fat becomes _____ with heat, and ____with cold

A

fluid
stiff

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57
Q

what is thermal pollution?

A

changing the temperature of an environment via human discharges (effluent from nuclear power plants)

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58
Q

some archaebacteria are _______ and can live at temperatures up to 110 degrees celcius

A

thermophilic (heat loving)

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59
Q

the ______ structure of ice can damage living ___.

A

crystalline
cells.
marine vertebrates are susceptible to freezing

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60
Q

what do glycerol and glycoproteins do for marine animals?

A

they are chemicals present in some animals (Arctic cod) that prevent freezing by reducing the strength of hydrogen bonds or via supercooling.

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61
Q

what is supercooling?

A

process when the glycoproteins in blood will prevent ice from forming around its “seed” by coating any potential ice crystal that’s forming and basically shuts down the process immediately

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62
Q

what is thermal optima?

A

the range of temperatures in which an organism best preforms. determined by the properties of the organism that influence the ability to function (enzymes, lipids, body form, the structure of cells and tissues)

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63
Q

provide an example of current treats to thermal optima

A

coral bleaching crisis: high temperatures causing corals to expel their symbiotic algae. bleaching can begin if temp is just 1 degree higher than average

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64
Q

nutrients in plants are obtained as _____ dissolved in water held by the _____

A

ions. soil

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65
Q

provide where plants get their nutrients from. what factors cause the availability of these ions to vary?

A

ammonium (NH4+), nitrate (NO3-), phosphate (PO4 3-), calcium (Ca2+), and potassium (K+). the availability of these ions varies with soil temperature, pH, and the presence of other ions

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66
Q

what is water potential? what are the units of water potential?

A

a measure of water’s potential energy; affects the movement of water in soil from one location to another. water potential is quantified in units of pressure, mega pascals (MPa).

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67
Q

what is matrix (matric) potential?

A

the potential energy generated by the attractive forces between water molecules and soil particles; occurs because both water and soil molecules have electrical charges.

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68
Q

in saturated soil, most water does not touch other soil particles and is not strongly held by the soil; hence its matric potential is ______

A

0 MPa

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69
Q

when gravity drains the water in soil, the matric potential drops to _____

A

-.01MPa

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70
Q

what is the field capacity of a soil?

A

the maximum amount of water held by the soil against the force of gravity

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71
Q

matric potential ________ as plants extract more water from the soil.

A

decreases.

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72
Q

what is the wilting point?

A

the wilting point is the minimum amount of water in a soil that the plant requires not to wilt. (-1.5MPa). Creosote King Clone is extremely drought tolerant and has a -5MPa

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73
Q

what are the three particle sizes of soil?

A

sand (>.05mm diameter) largest
silt (.002-.05mm diameter)
clay (.002mm diameter) smallest

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74
Q

what type of soil particles holds more water, more tightly and why?

A

smaller particles (clay) have a higher surface area relative to their volume, allowing them to hold more water

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75
Q

what type of soils are the best for growing plants?

A

Loam–a mixture of sand, silt and clay (~20% clay, 40% silt, and 40% sand)

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76
Q

_____________ affects field capacity and wilting point

A

soil composition

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77
Q

how do plant roots uptake water from the soil?

A

1) water moves into the roots by osmosis and then into the xylem
2) water molecules form a cohesive column in the xylem, roots, and stem
3) tension pulls the water column upwards and outwards in the xylem of veins in the leaves
4) water evaporates from mesophyll cells and water vapor diffuses out of the stomates.

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78
Q

what is root pressure?

A

osmotic potential in the roots of a plant draws in water from the soil and forces it into the xylem. osmotic potential can raise water ~20m

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79
Q

water is carried from the roots to leaves through the ___

A

xylem cells

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80
Q

what is cohesion?

A

mutual attraction of water molecules (hydrogen bonds); this allows water to move up through the empty remains of xylem cells.

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81
Q

what is transpiration?

A

the process by which leaves can generate water potential as water evaporates from the surfaces of leaf cells

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82
Q

______ are pores on the underside of leaves that allow CO2 inside the cell and water out. The _______ control when they open and close

A

Stomata, guard cells

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83
Q

what is the cohesion-tension theory?

A

the mechanism of water movement from roots to leaves is due to water cohesion and water tension.

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84
Q

when was the first photosynthetic bacteria? when was the first cyanobacteria? when was the first green algae?

A

3.4 billion years ago (Sulfur was produced)
2.7 billion years ago (first O2 producing organism)
.75 billion years ago

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85
Q

is Earth a closed or open system? what is Earth’s primary source of energy?

A

closed system; sunlight

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86
Q

briefly describe the food chain

A

primary producers –> primary consumers –> secondary consumers –> apex predators –> decomposers –> inorganic nutrient pool

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87
Q

light from the sun is either …

A

absorbed (heat), transmitted or reflected

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88
Q

explain why plants are green

A

plants can’t absorb green light, and they reflect the green light back to our eyes

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89
Q

what are the units of electromagnetic radiation?

A

photons

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90
Q

what is PAR?

A

Photosynthetically Active Radiation (400nm (violet) to 700 nm (red)). visible light only represents a small part of the light spectrum and includes PAR.

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91
Q

photon energy is _____ related to frequency and ______ related to wavelength.

A

positively
inversely

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92
Q

what are chloroplasts? what do they contain?

A

specialized cell organelles found in eukaryotic photosynthetic organisms. chloroplasts contain stacks of thylakoid membranes surrounded by fluid-filled space (stroma).

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93
Q

_______ and ______ are pigments found inside of the thylakoids that absorb light. _______ is found in all plants and is primarily responsible for photosynthesis

A

Chlorophylls and Carotenoids.
Chlorophyll A

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94
Q

write the photosynthetic formula

A

6 CO2 + 6 H20 + photons –> C6H1206 + 6 02

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95
Q

describe the two different steps of C3 photosynthesis

A

1) “photo” light reactions: light photon is absorbed by the chlorophyll, electrons are released, H20 in plant is split into O2 and H+ ions (O2 is released as a product). H+ ions and electrons produce ATP and NADPH. plants take in CO2 via stomata.
2) Calvin Cycle: Rubisco enzyme combines RuBP (5 Carbon sugar) with CO2 to form organic carbon containing compounds (glucose, starch)

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96
Q

explain the tradeoff plants face in regard to their stomata

A

when plants keep their stomata open, they lose a lot of water via transpiration. however, when they keep their stomata closed for a long time, they have low levels of CO2 within their leaves which slows plant growth and may cause them to photo respirate

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97
Q

explain how transpiration has a cooling affect?

A

it takes energy (in the form of heat) to convert liquid water into gas

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98
Q

when conditions are hot and dry, stomata like to _____ and Rubisco can capture ____ instead of _____. this process is called ______ and results in no net gain in energy for the plant, instead a loss of carbon and energy.

A

close
O2 instead of CO2.
photorespiration

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99
Q

is C3 photosynthesis optimal in hot and dry conditions?

A

no, plants will end up in net loss of energy/carbon

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100
Q

what is the most abundant enzyme on Earth?

A

RUBISCO (Ribulose biphosphate Carboxylase/ Oxygenase)

high N content, responsible for the C fixation in Calvin Cycle

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101
Q

what are 4 different plant adaptations to decrease water loss?

A

1) modified photosynthetic pathways (C4 and CAM photosynthesis)
2) reduce leaf area to root area ratio
3) dormancy/leaf loss during droughts
4) create boundary layer (spines and hair)

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102
Q

explain how the boundary layer aids in conserving water

A

air flow is lower with a boundary layer due to increased resistance to flow which decreases evaporation and traps moisture

103
Q

explain what C4 photosynthesis is

A

CO2 uptake and carbon fixation are physically separated in space. CO2 is temporarily stored in 4 carbon acids and then the carbon fixation reactions occur in Bundle Sheath Cells instead of Mesophyll cells.

104
Q

what percentage of land photosynthesis is done using C4 photosynthesis?

A

~25%. more water efficient, less light efficient (require high light)

105
Q

explain what CAM photosynthesis is

A

CO2 uptake and carbon fixation are separate in time (temporal separation). early morning/night: uptake of CO2 through stomata, C is stored in 4C molecule
daytime: stomata close to reduce water loss, energy is available from light reactions and the stored CO2 moves to the Calvin cycle for the carbon fixation process to continue.

106
Q

C4 and CAM plants are more __________________ than C3 plants, but less energy efficient when water is not ________

A

water-use efficient
limiting

107
Q

convergence: C4 pathways evolved _____ times in ___ families of angiosperms; >8000 species evolved adaptations to minimize losses to photorespiration

A

45 times in 19 families

108
Q

what type of plants tend to use C4 and CAM photosynthesis?

A

cacti and plants in very dry, arid climates

109
Q

explain why leaf size is important for leaf energy balance

A

when leaves overheat, they require more transpiration for evaporative cooling = more photorespiration = bad. small leaves with a high density of veins prevent loss of leaf tissue via embolisms which are common in water-stressed environments

110
Q

what are embolisms?

A

air bubbles in plant veins

111
Q

explain how root depth impacts a plants ability to maintain its water balance

A

long roots can access deeper water (roots are 90% of plant biomass is desert and semiarid grasslands).
shallow roots can take up water after brief rainfall events (roots are ~25% of plant biomass in coniferous forests).

112
Q

what are the 6 primary nutrients essential for plant growth?

A

carbon, hydrogen, oxygen, potassium, nitrogen and phosphorus

113
Q

what is homeostasis?

A

an organism’s ability to maintain constant internal conditions in the face of a varying external environment.

114
Q

what is negative feedback?

A

internal response mechanisms that restores a system to a desired state or set point when the system deviates from that state.

115
Q

land plants transpire ______ of grams of H2O for ________ of biomass they create.

A

100s
each gram

116
Q

how do plants excrete excess salts taken up in water from soil?

A

their roots serve as kidneys, and they expend energy (active transport) to pump excess salts back into soil.

117
Q

how do animals adapt to salt and water imbalances?

A

the desert kangaroo rat conserves water by only hunting during the night and staying below ground during the day; they also have larger kidneys that allow increased water retention.

animals that live near saltwater have special adaptations that allow them to limit salt consumption through special salt-secreting organs (modified tear, nose and ear glands).

118
Q

there are adaptive tradeoffs between water and energy conservation. animals need to invest _____ to conserve _____ when it is limited. however, when water availability is high, the need to conserve carbon is _______

A

carbon (energy) to conserve water
low

119
Q

animals excrete nitrogen waste in different forms…. aquatic organisms secrete ______.
mammals secrete ______.
birds and reptiles secret _______

A

ammonium (NH3)
Urea
Uric Acid

120
Q

what are Notothenioids? How did they adapt to freezing temperatures?

A

122 marine species found in Antarctic waters. they have antifreeze glycoproteins in their blood, <1% of hemoglobin (red blood cells). their optimal temperature range is -2-4 degrees Celsius. they will die at temperatures above 5 degrees C.

121
Q

explain how White Nose Syndrome (WNS) in North American bats is a threat to their ability to thermoregulate

A

WNS is a fungal infection that covers the muzzle of the bat and disrupts bats’ torpor (short term hibernation when they lower their metabolism) by waking them up during their torpor which causes them to starve to death.

122
Q

what is the difference between climate and weather?

A

weather is the variation in temperature and precipitation over periods of hours or days; describes current conditions and is largely unpredictable. climate is the typical atmospheric conditions that occur through a year; describes long-term patterns based on past decades

123
Q

what factors drive climate?

A

change in solar radiation, ocean circulation patters, albedo (reflectance) of earth’s surface and topographic variation

124
Q

climate, land topography, and soil type describes ________ _______ _______ variation

A

large scale spatial

125
Q

plant structure and animal behavior describes _______ ________ variation

A

small scale

126
Q

the extent of the space affected by an event is usually related to an event’s ________ in ______

A

duration in time

127
Q

variations in topography and geology are generated at a ______ pace than aquatic and atmospheric variations

A

slower

128
Q

what terms are key in describing organisms’ adaptations to their environment?

A

evolution by natural selection (individuals with better fitness are those with randomly generated (heritable) variations that best suit their current environment. those individuals will pass more copies of their genes, and that phenotype will come to dominate)

129
Q

_______ result from genes interacting with environments; organisms have a genetic basis, but the environments also sends signals to the specific genes which have the ability to turn on and off, which causes ________ ________ to develop

A

phenotypes
different phenotypes

130
Q

what is a phenotypic trade-off?

A

a situation in which a given phenotype experiences higher fitness in one environment, whereas other phenotypes experience higher fitness in other environments.

131
Q

what is phenotypic plasticity?

A

the ability of a single genotype to produce multiple phenotypes

132
Q

phenotypic plasticity allows organisms to achieve ________ if environmental conditions vary

A

homeostasis

133
Q

how do plants of the same species vary at different elevations?

A

typically, plants located at lower elevations have taller stems and those at higher elevations have shorter stems

134
Q

when environmental variation results in phenotypic trade-offs, natural selection will favor the evolution of __________ _________

A

phenotypic plasticity

135
Q

what is the difference between humans acclimating (responding to low oxygen levels) and humans adapting?

A

acclimation is rapid and reversible (behavioral/physiological) and occurs when individuals adjust to their environment (faster heart rate, greater production of red blood cells). vs adapting is long-term, evolutionary process that is not easily reversible (genetically determined) and occurs when a population becomes better suited to its habitat (higher hemoglobin levels).

136
Q

how do many species respond to the presence of predators?

A

many species alter their growth, body shape, and behavior in response to predators. these adaptations improve prey’s fitness by making it more difficult for the predator to find or consume the prey.

137
Q

plants also have the ability to respond to the presence of herbivores by producing what?

A

plants develop leaf hairs (trichomes) and glucosinolate compounds that makes the leaves difficult to consume/breakdown.

138
Q

organisms have evolved a variety of phenotypically plastic strategies for high and low _______

A

competition. ex: some organisms alter their digestive morphology so they can extract more nutrients from ingested food. (Burmese python)

139
Q

what are hermaphrodites?

A

individuals that produce both male and female gametes; individuals are able to fertilize their eggs with their own sperm.

140
Q

what is inbreeding depression and how do species avoid this?

A

inbreeding depression is the decrease in fitness caused by the mating of close relatives due to offspring inheriting deleterious alleles from both the egg and sperm. species avoid this inbreeding depression by waiting until self-fertilization is their last chance for reproduction.

141
Q

many organisms can adjust their __________ to maintain activity across different environmental __________.

A

physiology
temperatures

142
Q

many organisms respond to temperature by moving to microhabitats. what are microhabitats and what is an example of one?

A

microhabitats are locations within a habitat that differ in environmental conditions from the rest of the habitat. ex: the desert iguana regulates in body temp by burrowing in the ground when it’s too hot and by basking on rocks when it’s too cold.

143
Q

most animals can move to different microhabitats where water is more available. in response to scarce water resources, what can plants do to adapt?

A

many plants will close their stomata or adjust relative allocations of energy and material to grow longer roots. they can also use modified photosynthetic pathways (C4, CAM), create a boundary layer, and go dormant during droughts.

144
Q

how do organisms respond to extreme environmental conditions?

A

1) migration (moving)
2) storage (hiding)
3) dormancy (avoidance)

145
Q

what is migration?

A

seasonal movement of animals from one region to another. occurs when conditions are so severe that changes would not be worth the cost.

146
Q

the decision to migrate is a ______ ________ in response to changing environmental conditions such as temperature or food supplies

A

plastic behavior

147
Q

when resources are limited and migration is not possible, storage of resources can be an adaptive strategy. how can animals store excess food resources? what about plants?

A

animals accumulate fat or hide/store food supplies as a reserve of energy for periods of harsh weather when food is inaccessible. plants can store excess nutrients and energy in their roots.

148
Q

what is dormancy? how many different types of dormancies are there?

A

a condition in which organisms dramatically reduce their metabolic processes. there are 4 different types of dormancies.

149
Q

what are the four types of dormancies?

A

1) Diapause
2) Hibernation
3) Torpor
4) Aestivation

150
Q

what is Diapause?

A

involves a partial or complete physiological shutdown in response to unfavorable conditions; common in insects.

151
Q

what is hibernation?

A

individuals reduce the energetic costs of being active by lowering heart rate and reducing body temperatures; common in mammals.

152
Q

what is Torpor?

A

a brief period of dormancy in which individuals reduce their activity and body temp; common in birds and mammals.

153
Q

what is Aestivation?

A

the shutting down of metabolic processes in the summer in response to hot or dry conditions; common in desert tortoises, snails, and crocodiles.

154
Q

how do organisms adapt to prevent freezing?

A

-some animals burrow in places where temperatures are warmer.
-many amphibians can freeze solid underground by producing antifreeze compounds that form ice crystals around the cells rather than in them.

155
Q

what is central place foraging?

A

acquired food is brought to a central place (ex: a nest with young birds). as an individual forages farther away from its’ central place, it finds more resources, but this increases the energetic costs and the amount of food that the individual has to bring back.

156
Q

what do foraging decisions depend on?

A

-the time needed to travel round trip to site with resources (travel time)
-the time spent obtaining food at the site (searching time)

157
Q

what is handling time?

A

the amount of time a predator takes to search, handle, and consume a captured prey.

158
Q

the amount of energy gained per unit time is …

A

the energy benefit of a resource divided by the handling time. a predator should always eat the prey species that provides the highest amount of energy per unit time.

159
Q

more foragers consume a _______ _______ because one type of food may not provide all of the necessary ________.

A

varied diet
nutrients

160
Q

what did Joseph Fourier discover?

A

The greenhouse effect. Without the greenhouse effect, there would be no life on earth.

161
Q

What is the greenhouse effect?

A

The process of solar radiation striking the Earth, being converted to infrared radiation and being absorbed and re-emitted by atmospheric gases.

162
Q

Human produced gases, ______, exist at ____ concentrations but absorb relatively more infrared radiation and persist in the atmosphere for ________ of years

A

CFCs (chlorofluorocarbons)
low
hundreds

163
Q

what are some examples of greenhouse gases?

A

H20, CO2, N2O, CH4, and O3

164
Q

How and why do global temperatures vary depending on latitude?

A

The sun strikes Earth at the equator at a much more perpendicular angle than in the northern or southern poles where the suns energy is spread over a larger area. At the equator, the earth receives more intense and direct sunlight

165
Q

What is albedo?

A

the fraction of solar energy reflected by an object. Some surfaces have higher albedo than others do.

166
Q

______ _____ surfaces reflect more light back than ______ ____ surfaces do

A

Light colored
dark colored

167
Q

The _____ albedo of forests at the equator _____ average temperatures. The ____ albedo of snow at the poles ____ average temperatures

A

Low, increases
High, decreases

168
Q

The change is albedo of arctic ice creates a ________ _________ _____

A

Positive feedback loop

169
Q

How much of arctic ice has melted since the 1970s?

A

40% decline since 1970s. thickness decline from 3-4m to 1-2m.

170
Q

What other factor contributes to the change is albedo seen in arctic ice?

A

Combustion, industrial pollution, and wind blown sand create little dark specks on the glacial ice which changed the albedo of that surface and decreases the amount of sunlight reflected back.

171
Q

What are atmospheric convection currents?

A

The circulation of air between the surface of Earth and the atmosphere, caused by the properties of air

172
Q

As air temperatures increase, air can hold _____ water vapor. If water vapor exceeds saturation, what happens?

A

More
If water vapor exceeds saturation, water condenses to liquid or ice and produces a cloud or precipitation.

173
Q

_______ occurs when the temperature of saturated air decreases

A

Condensation

174
Q

What is Adiabatic cooling?

A

Cooling effect of reduced pressure on air as it rises higher in the atmosphere and expands

175
Q

What is Adiabatic heating?

A

Heating effect of increased pressure on air as it sinks towards the surface of Earth and decreases in volume.

176
Q

_______ ________ _________ is when water releases energy in the form of heat and warms the air when water vapor is converted back to liquid

A

Latent heat release

177
Q

Explain how Hadley cells form//why are there deserts at 30° N and S from the equator?

A

At the equator, the sun heats up the moist, tropical air which causes it to rise, this rising air experiences Adiabatic cooling which condensation and rain. The condensation of water vapor produces latent heat release which causes the air to expand and rise further up into the atmosphere. The warm, rising air displaces the cooler, drier air above it to the north and south. The cool, dry air experiences Adiabatic heating so it reaches the surface as warm, dry air and flows back to the equator.

178
Q

What is the Coriolis effect?

A

The deflection of an objects path due to the rotation of Earth. Winds push the layers of ocean beneath them into the same rotating gyres.

179
Q

Surface currents control the motion of the top ___% of water, while deep ocean currents mobilize ___% of water.

A

10
90

180
Q

What is upwelling?

A

The upward movement of ocean water that occurs along continents where surface currents move away from the coastline. Since deep waters tend to be high in nutrients, upwelling zones are often highly biologically productive and have high fish biomass

181
Q

what is the thermohaline circulation?

A

A global pattern of surface and deep water currents that flow as a result of variations in temperature and salinity that change the density of the water

182
Q

Is the global conveyor belt (thermohaline circulation) speeding up or slowing down and why?

A

Slowing down because more glacial ice is melting and adding in a flux of freshwater.

183
Q

What is ENSO?

A

El niño southern oscillation. Has a 3-10 year cycles and is an example of teleconnection. (Jacob Bjerknes)

184
Q

Under El Niño conditions, the thermocline ______ and the upwelling of nutrients _____, and fisheries become ______ productive.

A

Flattens, stops, less

185
Q

In El Niño, describe South America and south east Asia

A

South America: warm water and los pressure storms
SE Asia: droughts

186
Q

What factors are used to determine if we are in El Niño, La Niña, or neutral?

A

sea surface temperatures, atmospheric pressure, air temperature, cloudiness, and wind velocity (E, N) over tropical Pacific Ocean

187
Q

In the south west US, the winters are ___ during El Niño, and winters are ____ during La Niña

A

Wet
Dry

188
Q

oceans and lakes cover ___% in the northern hemisphere and ___% in the southern hemisphere. since water generates _____, more rain falls in the ______ hemisphere

A

61%
81%
precipitation
Southern

189
Q

_____ moderates land temperature by warming air in the winter and cooling air in the summer, so land temperatures in the _______ hemisphere tend to vary more.

A

water
Northern

190
Q

the interior of a continent usually experiences ____ _______ than its coasts because it lies further away from the ocean, therefore the interior varies _____

A

less precipitation
more

191
Q

describe what a rain shadow is

A

a rain shadow is a region with dry, arid conditions found on the leeward (far) side of a mountain range as a result of humid winds from the ocean causing precipitation (adiabatic cooling) on the westward side of the mountain.

192
Q

Hadley circulation review: warm air rises, expands, and cools, _______ _______, losing its capacity to hold water. as the cool air sinks, it warms, _________ __________ and increases its water holding capacity

A

adiabatic cooling
adiabatic warming

193
Q

how many biomes do we have and what factors are they predominantly determined by?

A

9 and they’re based on temperature and precipitation.
there are three temp. ranges: <5 degrees C, 5-20 degrees C, and >20 degrees C

194
Q

______ are highly productive soils, containing high organic matter and calcium

A

Mollisols

195
Q

_______ are deeply old and weathered soils with high clay + iron content; not very fertile/productive due to a lot of leaching and chemical weathering

A

Oxisols

196
Q

what are 5 determining characteristics of soil?

A

parent material (bedrock)
climate
vegetation (feedback)
local topography
age (weathering)

197
Q

what is the definition of soil?

A

soil is the layer of chemically and biologically altered material that overlays bedrock or other unaltered material at the Earth’s surface

198
Q

what are horizons?

A

distinct layers of soil; referred to as letters

199
Q

describe soil master horizons

A

O horizon: organic matter
A horizon: additions, topsoil
E horizon: eluviation, exiting
B horizon: illuviation, accumulation
C horizon: consolidated parent material
R horizon: bedrock

200
Q

what does leaching mean?

A

process in which groundwater dissolves substances, moving them down to lower soil horizons.

201
Q

what is weathering?

A

physical and chemical alteration of rock near Earth’s surface; occurs when water penetrates into parent material and dissolves soluble minerals. this produces insoluble materials such as clay

202
Q

what is the cation exchange capacity of a soil?

A

the ability of soils to retain cations (Ca and potassium).

203
Q

younger soils have _____ weathering time, _____ cations and are _____ fertile.

A

less
fewer
less

204
Q

what is laterization?

A

breakdown of clay in which silicon (Si) is leached from the soils, and iron (Fe) and aluminum (Al) dominate throughout the soil profile. this lowers the soil fertility and occurs in tropical and subtropical biomes where soils weather to great depths

205
Q

what is podsolization?

A

occurs when plant material is broken down slowly, clay particles break down in E horizon and soluble ions are transported to lower B horizon, leaving sandy layer with low nutrients. this produces acidic soils with distinct horizon bands. common in cool, moist biomes with mild precipitation (spruce/fir forests)

206
Q

soil is a _______ resource and ____ % of land is moderately to highly degraded

A

non-renewable resource
33%

207
Q

what are the action priorities for restoring soils?

A

1) minimize soil degradation and restore productivity of degraded soils
2) target regions where people are most vulnerable
3) stabilize or reduce global use of fertilizers
4) stabilize global stores of organic matter (carbon and organisms)
5) improve our knowledge of soil health trends

208
Q

what is the definition of biomes?

A

geographic regions that contain communities composed of organisms with similar adaptations. this occurs because of convergent evolution.

209
Q

what are terrestrial biomes determined by?

A

temperature and precipitation

210
Q

what is convergent evolution?

A

a phenomenon in which species descended from unrelated ancestors are similar because they have evolved under similar selective forces. ex: desert plants across different biomes adapt similarly to conserve water

211
Q

what determines saguaro distributions?

A

1) tolerance tradeoffs to physical factors: drought adapted, cold intolerant.
2) species interactions: predation (rodents, bacteria), competition, and symbiosis (nurse plants, pollinators)
3) history and chance: disturbance (cattle, fires, invasives)

212
Q

why are there no terrestrial cacti in Africa?

A

cacti evolved only in the Americas after Pangea had separated.

213
Q

plants in a particular biome experiences similar ________ _______ – characteristic adaptations evolved independently

A

selective pressures

214
Q

boundaries between biomes can be ______. there is often an association between the _______ forms in a biome and the ______ forms that live there.

A

unclear.
plant forms
animal forms

215
Q

why don’t cold biomes with high rainfall exist?

A

cold air molecules cannot physically hold enough water against gravity to exist in high rainfall conditions

216
Q

which desert biome is very very diverse in plant species, bee species, and animal species

A

Sonoran desert

217
Q

what is a climate diagram?

A

graphs that plot the average monthly temperature and precipitation of a specific location on Earth.

218
Q

what is the growing season for plants?

A

months that are warm enough to allow plant growth. temp must be warmer than 0 degrees Celsius. plant growth is restricted by temperature when the temp line goes below the precipitation line, and vice versa.

219
Q

what are Anthromes? what’re the different types of Anthromes?

A

anthropogenic biomes.
dense settlements, villages, croplands and rangelands

220
Q

what does CLM stand for?

A

Community Land Model

221
Q

describe the tundra biome

A

the coldest biome, characterized by treeless expanse above permanently frozen soil (permafrost). soils are acidic and nutrient pool and the upper soils thaw during the brief summer growing season. plants grow low to the ground to gain protections under snow and ice

222
Q

describe the Boreal Forest biome

A

densely populated by evergreen needle-leaved trees, with a short growing season and severe winters. soils are acidic and podsolized. litter decomposes slowly and accumulates, forming the largest reservoir of organic carbon on Earth. species diversity is low, but the biome is a major source of lumber and paper.

223
Q

describe the temperate rainforest biome

A

known for mild temperatures and abundant precipitation and is dominated by evergreen forests. warmer conditions are due to nearby warm ocean currents. these forests typically support low species diversity. in NA, these forests are dominated by redwoods and Douglas fir that can be 60-70m tall.

224
Q

describe the temperate seasonal forest biome

A

moderate temperature and precipitation conditions, dominated by deciduous trees (oak, maple, beech). conditions fluctuate because forests are not near warm ocean currents. precipitation exceeds transpiration. warmer and drier parts of this biome are dominated by pines. soils are podsolized, slightly acidic and support a layer of small plants under the dominant trees.

225
Q

describe the woodland/shrubland biome

A

characterized by hot, dry summers and mild, wet winters, a combination that favors the growth of drought-tolerant grasses and shrubs. there is a 12-month growing season, but dry summers, cold winters and frequent fires limit plant growth. dominated by Sclerophyllous vegetation, which has small and durable leaves that resist desiccation

226
Q

describe the temperate grasslands/cold desert biome

A

hot, dry summers and cold winters; dominated by grasses, non-woody flowering plants and drought-adapted shrubs. soils are low in acidity and nutrient-rich with lots of organic matter. unproductive, cold deserts occur when precipitation falls below 250mm.

227
Q

describe the tropical rainforest biome

A

warm and rainy (2,000mm) biome with multiple layers of lush vegetation. there is a canopy of 30-40m trees with an understory containing smaller shrubs, trees, epiphytes, and vines. species diversity is higher than anywhere else in the world. organic matter decomposes quickly; vegetation rapidly takes up nutrients. soils are devoid of humus and clay, and retain nutrients very poorly

228
Q

describe the tropical seasonal forests/savannas biome

A

warm temperatures and pronounced wet and dry season, dominated by deciduous trees that shed leaves during the dry season. savannas have long dry periods and contain grasses and occasional trees. fire and grazing maintain savannas. soils do not hold nutrients but the warm weather favors rapid decomposition and fast growth

229
Q

describe the subtropical desert biome

A

hot temperatures, scare rainfall, long growing seasons, and sparse vegetation. associated with dry, descending air of Hadley cells. soils are shallow and devoid of organic matter, and neutral in pH. moister sites support succulent cacti, shrubs, and small trees (palo verde, mequite)

230
Q

what are aquatic biomes determined by?

A

flow, depth and salinity

231
Q

what are the three major types of aquatic biomes?

A

1-marine (salinity = 35pp thousand)
2-freshwater (salinity = 0.5pp thousand)
3-brackish (mix of fresh + salt)

232
Q

what are the two biome classifications of freshwater?

A

rivers + streams
lakes + ponds

233
Q

describe what a Lotic biome is

A

flowing fresh water (rivers and streams).
-has a Riparian zone: terrestrial vegetation along rivers; influenced by seasonal flooding and elevated water tables.
-allochthonous: organic matter inputs (leaves) that come from outside of an ecosystem
-autochthonous: organic matter that is produced by algae and aquatic plants inside of an ecosystem.

234
Q

describe what a Lentic biome is

A

non-flowing water (ponds and lakes).

235
Q

what are lakes formed by (4)?

A

1-glacial retreat
2-geological activity (tectonic shifts)
3-dams (artificially)
4-broad bend of river cut off by channel shift (Oxbow Lake)

236
Q

artificial lakes (dams) trap a lot of _______

A

sediments. Lake Powell traps 100 million tons of sediments annually causing nutrient starvation

237
Q

what is the littoral zone (Lentic biome)?

A

the shallow area around the edge of a pond or lake containing rooted vegetation

238
Q

what is the limnetic (pelagic) zone (Lentic biome)?

A

the open water beyond the littoral zone, where the dominant photosynthetic organisms are floating algae (phytoplankton)

239
Q

what is the profundal zone (Lentic biome)?

A

the area in a lake that is too deep to receive sunlight; typically has low concentrations of oxygen

240
Q

what is the benthic zone (Lentic biome)?

A

the area with sediments found at the bottom of lakes, ponds, and oceans; is a habitat for many burrowing organisms.

241
Q

what are the 3 layers of ponds and lakes?

A

1-Epilimnion: the surface layer of water in a lake or pond. high dissolved O2 and PAR light wavelengths mean high productivity
2-Hypolimnion: deeper layer of water in a pond or lake; can include the lower limnetic profundal zone. lack of PAR light and high rates of microbe-driven organic matter decomposition create anaerobic conditions
3-Thermocline: slow mixing between the epilimnion and hypolimnion creates a middle depth of water that experiences a rapid change in temperature over a relatively short distance in depth

242
Q

seasonal temperatures alter water ________

A

density. water becomes more dense as it cools to 4 degrees C and less dense as it cools below 4 degrees C.

243
Q

explain circulation in ponds and lakes

A

during the winter, water less than 4 dC sits beneath the ice. during the spring, surface waters warm and begin to sink. as surface waters continue to heat during the summer, they gain heat faster than deeper waters and float on the surface (stratification). as surface water cool in autumn, they begin to sink. vertical mixing exchanges benthic nutrients and oxygen from epilimnion and can cause algal blooms.

244
Q

what are the two biome classifications of Brackish (mix)?

A

1-Estuaries
2-Wetlands

245
Q

what are wetlands? what are two examples of wetlands?

A

water saturated soil with low oxygen-adapted plants.
1-salt marshes (high latitudes, >30dC)
2-mangroves (tropical/subtropical latitudes, water temp is >16dC)

246
Q

what are the ecosystem services that wetlands provide? what are their threats?

A

1-flood control
2-coastline protection from storms
3-“soak up” toxins (sewage, heavy metals, detergents)
4-habitat for migration water birds, invertebrates, and fish larvae

threats = drained and filled for development

247
Q

what are estuaries?

A

mouth of river, bordered by wetlands. very productive ecosystems (low water stress, and high nutrient loads)

248
Q

what are different types of threats to estuaries?

A

1-eutrophication
2-overfishing/overgrazing
3-drainage and filling of wetlands
4-sedimentation from soil erosion from deforestation upstream
5-pollutants (heavy metals, PCBs, radionuclides, and hydrocarbons)
6-diking or damming for flood control or water diversion

249
Q

___% of the world’s population lives near estuaries

A

60%

250
Q

what are the 4 types of marine biomes?

A

1-coral reefs
2-intertidal regions
3-oceanic pelagic zones
4-abyssal zones

251
Q

what are intertidal zones?

A

a biome consisting of the narrow band of coastline between the levels of high tide and low tide, from rocky coastlines to sloping mudflats. as the tide comes and goes water exhibits widely fluctuating temperatures and salt concentrations.

252
Q

what are coral reefs?

A

a marine biome found in warm, shallow waters that are ~20dC year-round. Corals are tiny animals in a mutualistic relationship with algae; corals produce CO2 and algae produce sugar. Corals live in colonies and their exoskeletons contribute to the structure of the reefs.

253
Q

what is the current threat to coral reefs?

A

cloral bleaching crisis: high temps cause corals to expel their necessary symbiotic algae.

254
Q

what is the open ocean?

A

the open ocean contains the photic zone (top 200m) where sunlight reaches, and the aphotic zone (beneath 200m) where only <1% of light reaches

RNR 316 (5 decks)

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